05 Symmetrix Foundations [Compatibility Mode]

8/7/2019 05 Symmetrix Foundations [Compatibility Mode]

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Copyright 2009 EMC Corporation. Do not Copy - All Rights Reserved.

The objectives for this module are listed here. Please take a moment to review them.

Symmetrix Foundations - 1


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The Symmetrix DMX series includes the Symmetrix DMX-4 950 and the Symmetrix DMX-4

models to meet a wide range of high-end requirements for scalability, performance, and cost.

DMX-4 models are ideal for high-end configurations that require performance and the scaling

capability to start as small as one Disk Adapter (DA) pair and 96 drives, and grow to amaximum of 4 DA pairs and 2,400 disks. The incremental scalability that the Symmetrix DMX-

prov es a ows you o mee your grow requ remen s y a ng s ap ers, s

channels, and disk drives non-disruptively to the existing DMX frame. This enables true pay-as-

you-grow economics for high-growth storage environments. The Symmetrix DMX-4 950 is an

ideal entry point for high-end configurations requiring one DA pair and between 32 and 360

drives. The same functionality, storage interoperability, and operational efficiency is maintained

across the entire Symmetrix DMX series for the DMX user community. And, the DMX-4 950

.

Key Feature - The massive scalability of Symmetrix is a key feature that enables customer to

reap the benefits of consolidation.



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The Symmetrix V-Max family. It includes two options for scalability and growth. The V-Max

series scales from 48 to 2,400 disks and provide 2 Petabyte of usable protected capacity when

configuring all 1TB SATA disks. The V-Max SE scales from 48 to 360 disks and is intended for

smaller capacity needs that require Symmetrix performance, availability and functionality.

The V-Max s stem can su ort u to 8 hi h availabilit V-Max en ines, with 512GBs of

protected, usable global memory. It provides support for Fibre Channel, iSCSI, Gigabit

Ethernet, and FICON connected hosts. Front end and back end connectivity has doubled over

the DMX-4 with up to 128 host ports and 128 disk channels. The V-Max also leverages 2.3

Gigahertz multi-core processors. The new Virtual Matrix provides the interconnect that enables

resources to be shared across all V-Max engines to enable massive scale out.



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With this launch, EMC announces two variations of the Symmetrix V-Max Series with

Enginuity options: Symmetrix V-Max array, and the Symmetrix V-Max SE array.

The Symmetrix V-Max array may be configured with one to eight Engines. It contains two16Directors, 96-2,400 disk drives, and a maximum of 128 Fibre Channel Front End ports, 64

FICON orts, or 64 Gi E/iSCSI orts.

The Symmetrix V-Max SE array always consists of a single Engine with two Directors.

Depending on expansion bay configuration, the system contains 48-360 disk drives, 16 FC Front

End ports, eight FICON ports, and eight GigE/iSCSI ports.



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Lets summarize our architectural discussion by comparing the Symmetrix V-Max array with the

DMX-4 on various scalability metrics.

On the back end, while both systems can support up to 2400 drives, the Symmetrix V-Max arrayoffers twice the capacity more than 2 PB of usable space. This can be achieved using 2400 1-TB

SATA II drives in a RAID-6 14+2 confi uration. The S mmetrix V-Max arra can also rovide

better performance on the Back End, since it can be configured with twice as many Back End

ports.

Relative to the memory, the Symmetrix V-Max array can be configured with up to 472 GB of

usable cache.

Front End scalability has improved as well for all three supported types of host interconnect,

and for remote replication connections.



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This slide lists some key terms used to describe Symmetrix systems. Please take some time to

review them.



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This slide shows some additional key terms used to describe Symmetrix systems. Please take

some time to review them.



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As service levels for critical applications escalate exponentially over the next decade, so will

requirements for information availability and data integrity.

Symmetrix is the gold standard for mission-critical applications. It has proven itself time andagain, over twelve years, in the worlds most demanding environments, including the data

centers of the lar est financial, insurance and telecommunications com anies.

Symmetrix was engineered to work flawlessly, to continue to run no matter what, and to be

serviced proactively and non-disruptively.

Symmetrix now raises the availability bar even higher with the worlds most advanced fault-

tolerant design featuring full redundancy, proactive monitoring and error detection and

correction.



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The Symmetrix DMX systems feature a high-performance Direct Matrix Architecture (DMX)

supporting up to 128 point-to-point serial connections within the DMX system. Symmetrix

DMX technology is distributed across all channel directors, disk directors, and global memory

directors in Symmetrix DMX systems. The matrix mid-plane provides configuration flexibilitythrough the slot configuration. Each director slot port is hard-wired point-to-point to one port on

eac g o a memory rec or oar . e e egance o s arc ec ure s s mp c y, no cus om

ASICs to interface between Directors and Global Memory, Memory and Disk and Directors and

Hosts .. This translates into less potential for component failure, scalability is easy, just add more

connections and faster CPUs on Directors. No lengthy cycles producing and debugging ASICs

(Application Specific Integrated Circuits). The simplicity of Symmetrix along with support for

more hosts and operating systems makes it the right choice for customers today.

Compare - The Direct Matrix Architecture is a key differentiator for Symmetrix. CLARiiON is

uses dual-controllers and the UltraScale architecture, providing customers with choices with

regard to performance, scalability, and reliability.



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Symmetrix DMX-4 is based on the proven Direct Matrix architecture, but with substantial

increases to communication line speeds and component counts. With point-point connections as

you can see in this diagram, we have eliminated potential bottlenecks, growth concerns and

performance by directly connecting the key components of the DMX including: Cache Memory,Front-End Channel Directors and Back-End Disk Directors. The DMX architecture is easy to

sca e y a ng more p ys ca connec ons as oppose o me-consum ng s pp ca on

Specific Integrated Circuits) that require more time to design and debug.

The connections between the Channel Directors (CDs) and cache, and the Disk Directors (DDs)

and cache run at 1 GB/sec, up by a factor of 2 over the previous Symmetrix model family

(DMX-3). The number of processors per director has also been doubled; there are now 8

processors per director. In addition to increasing the number of processors, the processors speeds

have been increased to 1.3GHz, a bump of 30%. With each new Symmetrix, EMCs

performance and capacity rise to new levels.

There are still four slices to each Channel Director and Disk Director, and each slice

incorporates two processors. The number of memory cards remains at 8, but the capacity of each

card has increased to 64GB of DDR memory, yielding 512 GB total memory.



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Symmetrix V-Max Series with Enginuity is the first implementation of the Virtual Matrix architecture.

The Symmetrix V-Max system is built around a scalable interconnect based on redundant RapidIO

fabrics. The current implementation uses two fabrics.

Engines represent the basic building blocks of a Symmetrix V-Max array. Each Engine contains a pair of

S mmetrix V-Max Directors. Each Director connects to both Ra idIO fabrics via Virtual Matrix

Interface ports.

This ensures that there is no single point of failure in the virtual interconnect.

A Symmetrix V-Max system may scale from one to eight engines. This provides a high degree of

flexibility and scalability. Shown is a logical view of a system that grows to the current maximum of eight

engines and 16 directors.

The design eliminates the need for separate interconnects for data, control, messaging, environmental and

system test. The dual highly-available interconnect suffices for all communications between the Directors,

thus reducing complexity.RapidIO is an industry-standard, packet-switched fabric architecture. It has been adopted in a variety of

applications including computer storage, automotive, digital signal processing and telecommunications. It

is important to note that the use of industry-standard RapidIO fabrics represents just one instantiation of


. . .

itself, the Virtual Matrix Architecture can support any number of redundant fabrics, and any number of

switching elements per fabric. The use of two RapidIO fabrics is a design choice that applies to the

current Symmetrix V-Max only these are not restrictions imposed by the architecture.


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This block diagram illustrates the interconnects between the various components within a

Symmetrix V-Max system. Also shown is the raw bandwidth limit for the current generation of

each interconnect. Of particular interest given the new distributed memory architecture is the

achievable aggregate bandwidth of the Virtual Matrix interconnect.

Data arrives on the left Front end I/O modules then is sent b the two CPU to the SIB module

which transfers in serial mode to the Virtual matrix for storage.



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Symmetrix V-Max array combines front end, back end and memory into a single director, reducing

cost and increasing performance.

As with all Symmetrix systems, the Global Memory is truly global in nature. In the Virtual Matrix

architecture, Global Memory is distributed across all directors. The Virtual Matrix allows access to

all Global Memory from all directors. Each director contributes a portion of the total Global

Memory space. Memory on each director stores the Global Memory data structures including:

Common area, track tables and cache entries.

A distributed Global Memory means that from the viewpoint of a director, some Global Memory is

local and some resides with other directors. The Virtual Matrix Architecture allows direct access to

local parts of Global Memory. Access to Global Memory on other directors is by way of highly

- -, , .

communicate with every other director. The Virtual Matrix Interconnectis a core logical construct of

the architecture, requiring some form of fabric-based, redundant mesh design in contrast to copper

etch on a single backplane. This form of interconnect ensures that the system can scale to large

numbers of directors. It also allows for directors to be dispersed geographically as the system grows

(in the future).



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The Symmetrix V-Max system uses engine-based packaging containing front end, back end and

memory components. The Symmetrix V-Max system implements a virtual matrix interconnect,

enabled by a new version of Enginuity.

As the table shows, the new architecture enables significant increases in scalability. Scalability

has im roved in all as ects: front end connectivit , lobal memor , back end connectivit and

usable capacity.



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The Symmetrix DMX-4 System Bay has:

Up to 12 channel directors

Up to eight disk directors (combined total of directors is 16)

Up to 512 GB global memory

, ,

Up to eight power supplies, each of which has:

A dedicated 2.2-kilowatt standby power supply (SPS)

Three cooling-fan assemblies, each containing three fans

Two power zones with independent power cables, each zone capable of powering the

fully-configured system bay



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The Symmetrix V-Max SE Series System Bay consists of a single V-Max Engine and eight drive

enclosures. The system bay for the Symmetrix V-Max array consists of one to eight V-Max Engines

(starting with Engine 4) and does not contain any drive enclosures. Both System Bays contain three

Standby Power Supply (SPS) trays, one Uninterruptable Power Supply (UPS), a Matrix InterfaceBoard Enclosure (MIBE), and a Server (Service Processor) with Keyboard-Video-Mouse (KVM)

.



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DMX-4 configurations deliver scalable capacity and performance to consolidate systems,

applications, and/or hosts while maintaining high service levels. Base configurations are

composed of a system bay and independent storage.

The DMX-4 Storage Bay is configured for capacities of 120 or 240 disk drives. Each Symmetrix

drive ba has redundant ower su lies with batter backu s to rovide standb ower to

components and two power zones with independent power cables. Each zone is capable of

powering the fully-configured drive bay and can be populated with any combination of

available drives. Speaking of drives, always consult PowerLink or Channel Express to

determine the latest drive offerings from EMC.

The Channel Express Configuration provides the proper number of storage bays, based on drive

.



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The Symmetrix V-Max array Storage Bay is similar to the Storage Bay of the DMX-3 and DMX-4

systems. It consists of eight to sixteen Drive Enclosures, 48 to 240 drives, eight SPS modules, and

unique cabling when compared with the DMX Series. The Symmetrix V-Max array Storage Bay is

configured with capacities of up to 120 disk drives for a half populated bay or 240 disk drives for afully populated bay. Drives, LCCs, power supplies, and blower modules are fully redundant and hot

.



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There are two dimensions to DMX-4 scalability: adding capacity by increasing the length of

existing drive loops or adding more DA pairs to scale capacity and performance.

Each disk director pair has eight redundant FC drive loops supporting up to 480 drives. Forexample, if a system were to be configured with 30 drive loops in quadrants 1 and 2, capacity

could be increased b addin one or two stora e Ba s, 3A and 4A, and increasin the loo

lengths to 45 or 60 drives per loop.

The only exception to this is the single DA pair where the maximum number of drives is 240. If

the starting system was a three DA pair configuration, DAs 6 and 11 could be added, increasing

back-end processing power and enabling an additional 8 drive loops in quadrant 4.

The Symmetrix DMX-4 series offers the ultimate in flexible scaling to allow independent

growth of performance and capacity to meet workload requirements.

As an example, a two-DA pair system with 240 drives could grow to 360 drives simply with the

addition of another drive bay. Or, if there are high workloads on the initial 240 drives, the most

appropriate way to build out the system might be to add one or more additional DA pairs to

support additional workloads, scaling performance upward as capacity increases.



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A fully loaded system either Symmetrix V-Max system or DMX-4 can accommodate up to

2400 disk drives, requiring 10 storage bays and one system bay.

The Symmetrix V-Max system with up to twice as many Back End ports requires shorter daisychains on the Back End.

e ou ng n e num er o rec or-pa rs re a ve o ear er mo e s ns ea o

we now have the notion of octants. The drive enclosures behind a given Director-pair constitute

one octant. This is conceptually similar to drive quadrants in a DMX-4 system.



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Unified Directors can hold different emulations depending on Mezzanine cards in use and can

be configured to support various interfaces.



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The Symmetrix DMX-4 global memory director technology is one of the most crucialcomponents of a Symmetrix system.

The DMX-4 uses global memory directors that use industry-standard Double Data Rate

Synchronous Dynamic Random-Access Memory (DDR SDRAM), the latest generation of DDRSDRAM chip technology. All read and write operations transfer data to or from global memory.

Any transfers between the host processor, channel directors, and global memory directors areachieved at much greater electronic speeds than transfers involving disks.

The DMX-4 global memory directors work in pairs. The hardware writes to the primary globalmemory director first, and then automatically writes data to the secondary global memorydirector. All reads are from the primary memory director. Upon a primary or secondary globalmemory director failure, all directors drop the failed global memory director and switch to anon- ua wr te mo e. Str p ng etween g o a memory rectors s e au t.

Each Symmetrix DMX-4 global memory director accommodates four separately addressable,

simultaneously accessible memory regions, which greatly reduces the probability of contentionfor global memory access.

Each global memory director has 16 ports with point-to-point serial connections between theglobal memory director and channel or disk directors (16 directors) through the direct matrix.


Each memory director port consists of a pair of full-duplex serial linkstwo serial links out(TX) and two serial links in (RX).


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Each of the eight director ports on the 16 directors connect to one of the 16 memory ports on

each of the eight global memory directors.

These 128 individual point-to-point connections facilitate up to 128 concurrent cacheoperations in the system.

e ymme r x sys em can suppor up o e g s o s n e m -p ane e ca e o g o a

memory and 512 GB of global memory (256 GB effective) global memory. Individual global

memory directors are available in 8 GB, 16 GB, 32 GB, and 64 GB sizes.

When configuring global memory for the Symmetrix DMX systems follow these guidelines:

Very large eight disk director configurations may be limited or restricted by currently available

-- .

Global memory directors can be added to the DMX-4 not to exceed the maximum designed for

the systems configuration.

Global memory directors must be configured in pairs of the same capacity.



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Lets take a closer look inside a Symmetrix V-Max Engine, and make some comparisons with DMX-4.

A Symmetrix Engine combines the front end, back end, and memory directors of a Symmetrix DMX system

into a single component. A single engine combines host ports, memory, and disk channels. It is configured to

provide highly available access to drives, as each Director is the primary initiator to the connected disks,and the alternate for the other .

In addition, the new Symmetrix provides twice as many host ports with up to 128 per system and is capable of

supporting thousands of physical and virtual server connections combining Fibre Channel, iSCSI, FICON, and

ESCON support.

The system also supports twice as many back end connections with up to 128 Point to Point Fibre Channel

ports. Twenty-four hundred disks are supported at general availability, and Enterprise Flash Drives, Fibre

Channel and SATA disks can be configured with a total usable protected capacity of over 2 PB in a single

system.

The new Directors introduce support for Multi-core processors that provide a significant increase in processing

power within a smaller footprint that can deliver up to 2X more system performance.

Because 5GB of local memory is reserved by each Director for control store & buffers, the total amount of

Global Cache is up to 944 GB of Global Memory, or 472 GB mirrored, protected memory. Global cache and

CPU complexes are redundant across each Director and allows resources to be dynamically accessed and


shared.

The new Virtual Matrix interface connects resources within and across Engines to share system resources. At

general availability, up to eight engines can be combined to provide massive scalability in a single system.


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This illustrates the layer levels of Enginuity and their functionality:

At the top of the layers is the Host communication point to the Symmetrix, at the bottom is the

actual Symmetrix hardware components, such as memory and directors.EMCs solution enabler APIs are the storage management programming interfaces that provide

an access mec an sm or manag ng e ymme r x, r -par y s orage, sw c es, an os

storage resources. They enable the creation of storage management applications that dont have

to understand the management details of each piece within the total storage environment.

Symmetrix systems support platform software applications for data migration, replication,

integration and more.



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At the core of all Symmetrix DMX systems is EMC Enginuity, the industry's most proven,

innovative storage operating environment. It enables consistency across generations of

hardware, and leverages new technologies. An operating environment tied to a time-proven

architecture is an operating environment that has captured, retained, and built on an existing andproven code base.

Enginuity is the software component which enables all of the advanced storage capabilities that

Symmetrix provides, including performance optimization, quality-of-service management, and

cache striping.

The maturity of Enginuity, along with the innovative use of new technology, allows it to support

a wide range of connectivity on both Mainframe and Open Systems.



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Enginuity is built for speed. It includes a number of intelligent algorithms to manage interface,

cache, and drive usage, providing Symmetrix with its industry-leading performance.

Even thought it is built for speed, Enginuity certainly is not lacking when it comes to the safetyof your data. It provides a plethora of features geared toward ensuring the integrity, availability,

and securit of our data.



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The numbers that define an Enginuity level have specific meaning. In this example, the 58

represents the V-MAX hardware, 75 is the microcode family, 121 is the field release level to the

microcode, and 102 is the field release to the service processor code.

Non-disruptive microcode upgrade and load capabilities are currently available for the

S mmetrix.



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The objectives for this lesson are shown here. Please take a moment to read them.



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In a Read hit operation, the requested data resides in global memory. The channel director

transfers the requested data through the channel interface to the host and updates the global

memory directory. Since the data is in global memory, there are no mechanical delays due to

seek and latency.

In a read miss o eration, the re uested data is not in lobal memor and must be retrieved from

a disk device. While the channel director creates space in the global memory, the disk director

reads the data from the disk device. The disk director stores the data in global memory and

updates the directory table. The channel director then reconnects with the host and transfers the

data. Because the data is not in global memory, the Symmetrix system must search for data on

the disk and then transfer it to the channel adding seek and latency times to the operation.



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A fast write occurs when the percentage of modified data in global memory is less than the fast

write threshold. On a host write command, the channel director places the incoming block(s)

directly into global memory. For fast write operations, the channel director stores the data in

global memory and sends a channel end and device end to the host computer. The diskdirector then asynchronously de-stages the data from global memory to the disk device.

A delayed fast write occurs only when the fast write threshold has been exceeded. That is, the

percentage of global memory containing modified data is higher than the fast write threshold. If

this situation occurs, the Symmetrix system disconnects the channel directors from the channels.

When sufficient global memory space is available, the channel directors reconnect to their

channels and process the host I/O request as a fast write.



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As cache size, disk size, and power requirements continue to increase, the time required to de-

stage data also increases.

Power Vault was designed to limit the time necessary to de-stage data and power off theSymmetrix system while on battery power.

ower vau e-s ages o a emory o spec c au ev ces on power own. en on

power up, it restores the image to Global Memory.

Five GB on each of the first four drives on every drive loop is reserved for memory vaulting.

The total capacity of all vault hypervolumes must be sufficient to keep two logical copies of the

persistent part of global memory.



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When configuring the Symmetrix there are different types of Hyper devices that can be

configured. For example:

Standard devices (STD) are configured for normal production operations

Virtual Devices (VDEV) are configured for TimeFinder/SNAP local pointer-based

replication

Dynamic Reallocation Volumes (DRV) devices are configured Symmetrix Optimizer hyper

re-location

Thin devices are virtual cache-only devices that can grow in capacity

Save Devices are configured for TimeFinder/SNAP and/or Thin devices

R1 and R2 for Remote replication



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Symmetrix physical drives are split into logical hyper volumes. Hyper volumes are then defined

as Symmetrix Logical Volumes and internally labeled with hexadecimal identifiers. A

Symmetrix logical volume is the drive entity presented to a host via a Symmetrix channel

director port. As far as the host is concerned, the Symmetrix Logical volume is a physical drive.

Do not confuse S mmetrix Lo ical Volumes with host-based lo ical volumes. S mmetrix

Logical Volumes are defined by the Symmetrix Configuration while Host-based logical are

configured by customers through Logical Volume Manager software. A hyper volume could be

used as an unprotected Symmetrix logical volume, a mirror of another hyper volume, a member

of a Symmetrix Meta LUN, a Business Continuance Volume (BCV), a member for Parity RAID,

a remote mirror using SRDF, a Drive Reallocation Volume (DRV), and more.



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Symmetrix arrays support open systems, main frame, and iSeries logical volume types. Each

system type uses a different size block. Open systems use the Fixed Block Architecture (FBA),

which is a 512 byte block. Mainframes require Count Key Data (CKD) format, which uses a

57KB track size. iSeries systems store data using a 520 byte block size.

S mmetrix DMX-4 arra s store FBA, CKD, and iSeries data in cache usin their native block

size. When destaging data to drives, DMX-4 uses 512 byte blocks for FBA and CKD data, and

520 byte blocks for iSeries data.

With V-Max, each 512-byte data block (520-byte for iSeries systems) is now digitally signed

with an 8-byte data-integrity field using an algorithm based on the T10-DIF standard proposal.

These additional bytes are appended to each 512-byte block on writes as the data enters the

, ,

system!. The bytes include not only a strong CRC, but also referential information that specifies

the LBA and generation of the data block. Enginuity uses this info to validate that the content of

the block hasn't changed, and that it is indeed the block of data from the requested LBA (just in

case the drive returned the wrong block of data). And in addition to this, Enginuity also keeps

separate check bits on track tables, which are stored separately from the data and the block

CRC as a belt-and-sus enders a roach to ensurin data inte rit .



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The best possible performance is only achieved if all the resources within the system are being

equally utilized. Through careful planning the best performance can be achieved. Planning

starts with understanding the host and application requirements.

Within the Symmetrix bin file, the emulation type, size in cylinders, count, number of mirrors,

and s ecial fla s (like BCV, DRV, D namic S are) are defined. Each S mmetrix lo ical volume

is assigned a hexadecimal identifier. The bin file also tells the Channel director which volumes

are presented on which port, and the address used to access it.

From the Hosts perspective, when a device discovery process occurs, the information provided

back to the Operating System appears to be referencing a series of drives. The host is unaware of

the bin file, RAID protection, remote mirroring, BCV mirrors, dynamic sparing, etc. In other

, .



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RAID 6 is an ideal protection option for high-capacity drives, such as the low-cost Fibre

Channel drives, where, due to the performance and capacity of these drives, the RAID rebuild

times can become elongated. RAID 6 minimizes the data-loss exposure in the event of a dual-

drive failure in the same RAID group. Only EMC offers support for both RAID 6 and low-costFibre Channel drives in the same system, which ensures a low-cost, but high-availability

en erpr se o er ng.

RAID 6 provides an option with higher resiliency that can sustain two simultaneous drive

failures within the same RAID group without downtime or data loss. RAID 6 support adds a

second, independent, distributed-parity scheme. Data and parity are striped on a block level

across multiple drives, similar to striped RAID 5 technology. RAID 6 is supported in 6+2 and

14+2 configurations. RAID 6 (6+2) has the same useable capacity as RAID 5 (3+1), and RAID 6

(14+2) has the same useable capacity as RAID 5 (7+1).



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Symmetrix systems have Dynamic Sparing data protection that reserves volumes as standby

spares. These volumes are not user-addressable.

The Dynamic Sparing function determines when a logical volume is about to fail, and copies thecontents of the disk device on which that volume resides to an available spare without any

interru tion in rocessin . The S mmetrix s stem notifies the EMC Customer Su ort Center of

this event with an Environmental-Data Present error, and then uses the spare until the device can

be replaced.



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Within the Symmetrix, each logical volume is represented by four mirror positions M1, M2,

M3, and M4. These Mirror Positions are actually data structures that point to a physical location

of a data mirror and the status of each track of data. Each position either represents a mirror or is

unused. For example, an unprotected volume will only use the M1 position to point to the onlydata copy. ON a DMX system, a RAID-1 protected volume will use the M1 and M2 positions.

s vo ume was a so pro ec e w , ree m rror pos ons wou e use , an we

add a BCV to this SRDF protected RAID-1 volume, all four mirror positions would be used.



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RAID Virtual Architecture implemented with Enginuity 5874 is the new method for handling device

mirror position usage and is based on the RAID 6 architecture introduced in the previous release.

First, lets take a look at how mirror position usage is handled in a pre-5874 Symmetrix array. One

fairly typical configuration is a mirrored device that is also SRDF protected. This configuration

leaves one mirror position available for operations such as TimeFinder Mirror, or hot sparing. In

cases where Concurrent SRDF is implemented, for example against a mirrored device, you are left

with no available mirror positions. With this configuration you cannot use TimeFinder mirror or hot

sparing. The RAID virtual architecture in Enginuity 5874 expands on the mirror positioning

handling implemented with RAID 6. Now, a mirror position holds a logical representation of a

RAID group rather than a device resulting in additional free mirror positions. Our initial example of

a mirrored device with SRDF no longer has two data devices consuming two mirror positions.

Instead the RAID 1 group occupies one mirror position with the SRDF protection occupying a

second position. This frees two mirror positions for other operations. Lets take a look at how this

new architecture changes our concurrent SRDF example. Again, the two data devices are replacedby the RAID group representation with each RDF device occupying additional mirror positions.

This frees up one mirror position giving the customer more flexibility. Virtualizing the RAID

Architecture is an enabling technology for Symmetrix to implement other features, such as VLUN


.

Keep in mind that RVA does not introduce new RAID protection levels. Also, be aware that the

optimizer swap process and definition of RAID groups are under RVA architecture and the historical

flags forMaintain RAID Groups, andMaintain Mirrors, are no longer required.


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To support the new distributed Global Memory implementation, Symmetrix V-Max systems use a

store-and-forward (S&F) architecture. In this version of the microcode, all I/O is completed from the

local S&F buffer, and then is moved to the relevant Global Memory space. Note that since Global

Memory is distributed, the relevant Global Memory space may reside either on the Director thatreceived the I/O, or on a different Director.

With this in mind, let us consider the various possible data flow scenarios when a host performs an

I/O request to a Symmetrix Logical Volume in this version of Enginuity. In our simplified

representation of a Director in these diagrams, we view the shared memory space as consisting of

three main sections: Global Memory, Store-and-Forward (S&F) Buffer, and Control Store. Control

Store is private memory reserved for control purposes such as hosting the microcode.

,

same Director. The read request from the host experiences a cache hit in a local Global Memory

slot; the CPU moves data from Global Memory to the Store and Forward buffer; and the I/O device

moves data from the Store and Forward buffer to the host.

In this simplest of cases, there is no traffic generated on the RapidIO fabrics since all activity is

local to one Director.



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In our second example, lets again consider a read cache hit.

But this time, the relevant cache slot is on a different Director from the one which provides Front

End connectivity to the host.

As before, the process starts with: a read request from the host experiences a cache hit in the remote

Next, the CPU moves data across one of the RapidIO fabrics from remote Global Memory in

Director 2, to the local Store and Forward buffer in Director 1; and finally, the I/O device moves data

from the Store and Forward buffer to the host.



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Our third example considers the general case of a read cache miss, with three Directors involved:

Director 1 where the host is connected; Director 2 which hosts the cache slot in Global Memory for

the I/O block involved in the read request; and Director 3 which services the disks requiring I/O

activity due to this cache miss.

,

Director 1. The cache slot happens to be allocated on Director 2 in this case note that any Director

may be selected for this purpose. Data is read from disk on Director 3 into the Store and Forward

buffer on Director 3; moved over the RapidIO fabric to the allocated cache slot on Director 2;

moved over the RapidIO fabric to the Store and Forward buffer on Director 1; and finally

moved to the host which is connected to Director 1.



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Our final example deals with the general case of a write I/O request to a Symmetrix Logical Volume.

Up to four Directors may be involved in the processing of this request.

In our example, Director 1 provides the front-end connection to the host, Directors 2 and 3 host the

mirrored cache slots for the particular I/O block of interest, and Director 4 provides the back-end

connection to the disk drives to which data must be destaged from cache.

Now lets look at the data flow for a write in this general case.

The write request is sent from the host to Director 1, and the data is placed in the Store and Forward

buffer on Director 1.

In this particular case, the cache slots happen to be allocated on Directors 2 and 3.

Next, data gets moved across the RapidIO fabric to the allocated cache slot on Director 2; moved

across the RapidIO fabric to the allocated cache slot on Director 3; read across the fabric into the

Store and Forward buffer on Director 4; and finally, destaged to disks on Director 4.



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The objectives for this lesson are shown here. Please take a moment to review them.



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ControlCenter is a complete set of storage management tools. The ControlCenter family delivers

storage resource management (SRM) that simplifies and automates such tasks as reporting,

planning, and provisioning for the large, complex information infrastructures including SAN,

NAS, DAS, and CAS.

As new A ents are inte rated or enhanced, the are seamlessl inte rated into the existin

environment. The storage environment can be managed from end to end with one tool. This is

the base functionality of ControlCenter.

Due to the interoperability of the architecture and the centralized storage of configuration

information, ControlCenter allows IT organizations to manage the service they provide, not just

the infrastructure they have.



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Symmetrix Manager provides:

A consolidated view of Symmetrix platforms

Real-time performance reporting

Extensive windowing capabilities for display of multiple systems

, , ,

Alert management for Symmetrix systems down to the component level



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SYMCLI resides on a host system to monitor and perform control operations on Symmetrix

arrays. SYMCLI commands are invoked from the host operating system command line (shell).

The SYMCLI commands are built on top of SYMAPI library functions, which use system callsthat generate low-level I/O SCSI commands to the storage arrays.

o re uce e num er o nqu r es rom e os o e s orage arrays, con gura on an s a us

information is maintained in a Symmetrix host database file (called the Symmetrix configuration

database; symapi_db.bin by default).

The target storage environments are typically Symmetrix-based though some features are

supported for CLARiiON arrays as well.



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For users of the Symmetrixthe most widely deployed high-end storage systemSymmetrix

Management Console provides intuitive, browser-based device management. EMC Symmetrix

Management Console (SMC) is an intuitive, browser-based graphical interface for managing

EMC Symmetrix systems. SMC is a key component of the EMC storage system managementsoftware portfolio which also includes EMC ControlCenter and EMC z/OS Storage Manager.

Symmetrix Management Console:

Provides full management control of individual Symmetrix systems for those environments

that do not need advanced Storage Resource Management capabilities, or for those that

simply need a lightweight graphical interface to complement their SRM infrastructure.

Reduces the complexities associated with a command-line interface for system management,

.

improve staff productivity and maximize utilization of the system resources, while reducing

access time to the critical business information.



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Starting with Enginuity 5874, Symmetrix Management Console can be accessed directly via the

service processor of a Symmetrix V-Max system. By joining the service processor to the

corporate network, storage administrators will have immediate access to SMC from anywhere

in the enterprise. Communication to the service processor must occur over a secure HTTPSconnection. This support for out of band management reduces TCO by eliminating the need for

e cus omer o purc ase an a ona server o manage e ymme r x w an or -

S Providers. Note, however, that a traditional implementation via installing SMC provider on a

dedicated host continues to be supported.

With this new implementation, there are two ways to login to SMC:

As a customer, with the default SMC username/password (this may be changed from the

'

As EMC/Partner Customer Service Engineer, with RSA credentials.



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Symmetrix Optimizer automatically tunesmonitors, analyzes, and migrateslogical volumes

to maintain optimal performance, with no disruptions to applications or users.

Symmetrix Optimizers load-balancing automation technology analyzes volume activity toidentify hot and cold logical volumes for swaps, then automates the time-consuming tasks of

back-end load-balancin and drive erformance-tunin .



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Symmetrix Performance Manager is a performance monitoring software tool. No other

performance-analysis tool on the market allows users to analyze Symmetrix, CLARiiON,

Celerra, and HDS performance with the ease offered by Performance Manager. Its unique

architecture gives users complete control over data collection and flexibility in data analysis.

With Performance Mana er, it is ossible to:

Boost productivity with the softwares extensive automation capability

Exceed service levels by pinpointing issues and needs in performance, implementation, and

capacity planning

Plan performance growth based on analysis of key performance variables

Use the output to optimize SAN, Symmetrix, and CLARiiON performanceand to manage

c anges n con gurat on



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StorageScope manages the tiered storage in the context of the business. With this product, users

can view usage and asset configuration automatically, making it easier to identify opportunities

to reclaim and reallocate storage capacity. ControlCenter StorageScope also gives access to

automated trending analysis and forecasting graphs.

The roactive mana ement of Stora eSco e File Level Re orter allows ou to reclaim stora e

capacity stage data to less expensive disk, and compress data files.



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This slide contains the objectives for this lesson. Please take a moment to read them.



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By utilizing role-based access control (RBAC), and verifying identity for remote users, the SE

software supports accountability, which in turn contributes to compliance monitoring and

auditing. The principle of least privilege states that any person (or process or system) should

only be given the privileges to perform the actions needed to do their job, and no more.

Solutions Enabler/S mmetrix Mana ement Console defines the followin roles.

Monitor Able to perform read-only (passive) operations on a Symmetrix array excluding

the ability to read the audit log or Access Control definitions.

StorageAdmin Able to perform all management (active, or control,) operations on a

Symmetrix array and modify GNS group definitions in addition to all Monitor operations.

Admin Able to perform all operations on a Symmetrix array, including security

.

SecurityAdmin Able to perform security operations on a Symmetrix array in addition to

all Monitor operations. Auditor Grants the ability to view, but not modify, security settings for a Symmetrix array

(including reading the audit log, symacl list, and symauth) in addition to all Monitor

operations. This is the minimum role required to view the Symmetrix audit log.



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The Symmetrix Management Console utility leverage the new capabilities provided by Solution

Enabler. Additionally, the Management Console also offers management of the Symmetrix

Access Control facility. All communication between the client and the Symmetrix is protected

by SSL encryption.



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Symacl provides host-based (not user-based) access control. Hosts are authenticated; when

enabled, symacl can restrict access by unauthorized hosts. Note that when initialized, all

permissions are granted to all hosts; this allows gradual implementation of an Access Control

Policy by permitting older hosts and applications to continue as before.

S macl restricts S mmetrix control functions, not the data ath between hosts and stora e

nodes. Permissions may be specified for all or a subset of Symmetrix devices.

What can you do with symacl?

List Access Control entries, access pools, access groups

Show state of the Access Control environment

Verify contents of command files for correct syntax

Check command files for appropriateness of the requested Access Control entry against the

current state

Commit commands to the Access Control database

Back-u the Access Control database


Restore the contents of the Access Control database


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The combination of the symacl and symauth facilities permit access control to the Symmetrix by

host identity or by user identity. Either, both, or none of these capabilities can be enabled.

Symacl allows hosts to be assigned to a access group. Devices on a given Symmetrix areassigned to device groups. Particular access permissions can be established for a particular

access rou and a iven device rou .

The default state for symacl is to allow all commands from all hosts.



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The Symmetrix storage device restricts access to data via two mechanisms. First is LUN

masking: the Symmetrix creates a mapping between various hosts (based on WWNs) and the

LUNs that are visible on that devices FA. Not all hosts are able to see all LUNs; if the mapping

is not present, the I/O request is refused.

Secondl , S ID lockdown revents a server from accessin an arra from a different fabric_

switch port than what the server originally connected to the fabric. When this capability is

enabled, the Symmetrix creates a mapping in the Volume Configuration Management Database

(VCMDB) that records the host WWN and the Fibre-Channel ID (FCID) for that device. Any

frame that subsequently arrives at the storage array must contain that same WWN/FCID pair;

otherwise, the frame is dropped.

available solely in the switch fabric, as well as preventing unauthorized access based on WWN

spoofing.



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Certified Data Erasure is a Symmetrix service to securely erase a given drive prior to taking that

drive out of service. The procedure to erase the data meets the requirements of DoD

specification 5220.22-M (1995). This specification indicates how many times data on the drive

must be overwritten, and with which kinds of data. Data from drives that have been subject tothis procedure is deemed to be unrecoverable.

This procedure supports data confidentiality, since the data cannot be retrieved following this

procedure.



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Symmetrix Security Credentials, powered by RSA, provides a highly secure method of

accessing the storage device. Service credentials apply to both console login and to remote

access via the EMC Secure Remote Support (ESRS) gateway.

The combination of user ID, role, device ID, and time window of operation provides a short-

lived credential that cannot be reused to ain mana ement control of the device at some future

time. This capability supports accountability. Because actions are also recorded in the tamper-

proof audit log, the combination of capabilities means that we have high assurance that not only

are activities being performed correctly but also provide proof of compliance.



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The Symmetrix Secure Audit Log is newly available in Enginuity 5772 code release. The log

records host-initiated actions, physical component changes, actions on the service processor, and

attempts blocked by security controls. As a security measure, event log contents cannot be

altered, and only authorized users (users in the auditor role) can retrieve log contents. Note thatthe log file rewrites itself after 40MB capacity limit is reached, so data must be captured

ex erna y one w s es o recor a a eyon e m .



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The EMC Multi-protocol and GigE IPv4/6 Channel Directors provide support for the latest

network protocol standards by integrating IPSec and IPv6. IPSec is a security protocol that

encapsulates the entire IP packet over a network between two hardware endpoints. IPsec is

integrated into the IPv6 protocol, and is an additional protocol with IPv4. It provides a standardmeans of authenticating and encrypting data sent over IP network connections, and reduces the

secur y r s s assoc a e w ransm ng a a over ne wor s, s nce can prov e access

control, connectionless integrity, data origin authentication, detection and rejection of replays,

confidentiality (via encryption), and limited traffic flow confidentiality.



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An embedded line-grade encryption co-processor provides strong security without degrading

performance. Session-based encryption keys simplify management while maintaining security

for data in transit.

IPSec can be used with Symmetrix arrays connected via RDF over GigE. This feature is

su orted both on IPv4 and IPv6 networks. Su ort for IPv6 alon side IPv4 allows customers to

integrate Symmetrix DMX-4 arrays into their next generation networks when they are deployed.

Customers can effectively manage Symmetrix communication and encryption with Symmetrix

Management Console (SMC) or SYMCLI. Either SMC and SYMCLI can be used to manage

IPv6 settings for front end GigE directors



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These are the key points covered in this module. Please take a moment to review them.



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Documents

05 Symmetrix Foundations [Compatibility Mode]