© 2007 Hitachi Data Systems

Hitachi Dynamic Provisioning Best Practiceswith Applications

23 January 2008

Steve BurrSolution Architect, Global Solution ServicesHitachi Data Systems

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Presentation Goal

• Discuss best ways of using Hitachi Dynamic Provisioning software with an emphasis on real applications

– Microsoft Exchange 2003, Microsoft Exchange 2007 – SQL Server 2005– Oracle 10g, Oracle 11g RAC

• Effective use of over provisioning

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Hitachi Dynamic Provisioning (HDP)

Host Servers only see Virtual Volumes

Dynamic Provisioning

Pools

Dynamic Provisioning

Virtual Volumes

(DP-VOLs)

LDEV LDEV LDEV LDEV LDEV LDEV LDEV LDEV

Disk Drives/Drive Groups

LDEVs(Pool-VOLs)

Actual storage capacity in Dynamic Provisioning

pool is assigned when host writes data

to new area of LUN

Hitachi Dynamic Provisioning

Volume shows“Virtual Volume”which doesn’t

have actual storage capacity

Write Data

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Hitachi Dynamic Provisioning Three Potential Benefits

Thin provisioning plus Hitachi Virtualization, Tiered Storage, Volume Migration

• Easier management– Simpler planning (reactive strategic management)– Avoid or defer tough decisions about LDEV size– Control, change and optimize: capacity, performance, reliability , cost tier

• Naturally balances performance– With large pools there are more spindles than static provisioning– May scale performance by growing pool

• Over provisioning capacity– Simplify capacity planning– Reduce need for “urgent change”– Reduce need for – “disk X on server Y has run out.

We’ll have to re-allocate the whole estate.”

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Capacity Leveling: Example

An example• Three Database Applications• Initial estimates: 500GB

1500GB Used 1500GB Free

• Actual use: 100GB, 200GB, 800GB

2000GB Used 1100GB Used400GB Free

N N N

PVV V

N N N

?

V VV

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Performance Leveling: Example

Small database

Largedatabase

Low I/O Easy Easy

High I/O Problem area

Good but needs design

Pool

ExampleMicrosoft Exchange 2007 design:

5,000 Mailboxes400 MB/mailbox (2TB)Workload = 1 IOPS/mailbox2 Servers

Design = 8*RAID-10(2+2) AG

But Find that some groups give hotspots so

redesign

ThenDecide to roll out BlackBerrysNew IOPS = 3 IOPS/mailboxBut 2TB is unchanged?

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Over Provisioning

Allocating more storage space to users than they’ll initially need

No over provisioning (rightsizing)• No growth benefit but performance and management benefits still applyMild over provisioning• Giving headroom for expansionAggressive over-provisioning• Greatest benefits• More than you’d want to buy, “Every LUN is 2TB”• Needs care and safeguardsAggressive but risk averse, over provisioning• Over provision aggressively but• Combine storage, application and OS techniques to remove risk• Great benefits with safeguards• Particularly good for early deployments, uncontrolled environments and test

environments

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How Dynamic Provisioning will perform with applications:

Will depend on • platform factors (particularly file system)• application factors (particularly storage configuration)• how it is managed

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File system factor 1 – Metadata

• Metadata: management information• Includes: times, names, directories, pointers to data, maps, label

– inodes, MFT, FAT– Where is it: start, end, multiplexed, how much touched?– When created

• Space is not wasted, just prematurely allocated• Still have management benefits and performance benefits

Metadata Rounded to page size

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File system metadata

JFS (VxFs) Top only

HFS Write by 10MBTop only

OCFS2 Top onlyWrite by 2GB (2%)

Linux

Write every 128MB (30%)

Write by 52MBTop onlyUnder examinationWrite every 64MB (65%)Top onlyTop only

Windows 2003 NTFS

With Max AUAt 4K page

With Max AU

XFSExt2, Ext3

UFSVxFSZFSJFSJFS2VxFS

AIX

Solaris

HP-UX

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File system factor 2 – reclaim policy

• If it starts efficient, what happens when it’s used?• May depend on how you use it.• Where does “next free block” come from?• Free space management:

– Table, bitmap or linked list of blocks– One or multiple lists, multiple levels

MRU – most recently used

LRU – least recently used

Examples…

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Metadata and reclaim policiesExamples of pool use

0

100

200

300

400

500

600

Used Pre-allocated

0

100

200

300

400

500

600

Used MRU

0

100

200

300

400

500

600

Used Allocated

0

100

200

300

400

500

600

LRU Used

pre-allocateUFS

LRU reclaimNTFS

MRU reclaimASM

“Leaky”OCFS2

Is this the only good one?

Pool Used versus “Space Used”

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Is reclaim always an issue?

• No – many storage requirements are quite static• Needs to be addressed:

if application creates and recreates files and file system doesn’t reclaim well

• Workarounds:– Don’t over provision– Use static provisioning– Administration methods…

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Controlling space

Dynamic Partition Expansion:1.Create and map over-provisioned volume2.But don’t allocate all to partition3.When top of partition is reached

OS is forced to reclaim4.If total space gets low5.Use OS to expand partition6.Can be scripted7.Generally easier than hardware add, lun resize etc.8.Recommended if you have no detailed guidelines9.Helps with metadata and reclaim issues

echo select disk 51 > diskpart.screcho select partition 1 >> diskpart.screcho extend size=600 >> diskpart.screcho detail disk >> diskpart.scrdiskpart /s diskpart.scr

ALTER DISKGROUP VS1DG RESIZE DISK DISKVS1 SIZE 738M;

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Application testing

• Construct lab with: application, test tools andHitachi Dynamic Provisioning software

• Test: volume manager, file system then application

• Monitor “allocated pool” versus “used space”whilst performing typical actions:

– Initial Creation and Configuration– Addition, Append, Modify, Deletion– Force Fragmentation– Backup and manage

• Analyze and produce guidelines

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Exchange 2003 and 2007 tests

• Microsoft loadsim and loadgen

• Realistic, unlike JetStress

• 10 days: 4.8m transactions, 1.3m messages read, 1.25m delivered, 350K deleted, appointments, attachments, dlists

• Set zero e-mail retention policy

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Exchange tests

Exchange Data Use with Dynamic Provisioning

10200

10400

10600

10800

11000

11200

11400

9:36 14:24 19:12 0:00 4:48 9:36 14:24 19:12

daily 0200 mdbspace reclaim

After days of testing.Gap normal.No increase over time.

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Exchange tests

Exchange Data Use with Dynamic Provisioning

0

5000

10000

15000

20000

25000

30000

35000

18/05 20/05 22/05 24/05 26/05 28/05 30/05 01/06

Don’t defragment

mdb!

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Exchange tests

Exchange Log Use with Dynamic Provisioning

010,00020,00030,00040,00050,00060,00070,00080,00090,000

18/05 20/05 22/05 24/05 26/05 28/05 30/05 01/06

Defragmentation did not help

Partition limit

Online Backup with truncate using Hitachi Protection Manager with VSS

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Exchange best practice

• Exchange 2003 and 2007 similar

• Good for Mail Stores (.mdb)– Mailbox management safe

• Storage Group Log files (.log)– Unlimited on NTFS, so either:

• don’t over provision, • use dynamic partition expansion• or use static provisioning

• Do not defragment

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SQL Server Tests

• No equivalent to Loadsim; used simple sql scripts• Create database, table, insert and drop rows:

7M records added/updated, 8M deleted, 3/4GB. • Investigate initial allocation and growth• Three data areas:

– Database (.mdf)– Online Log (.ldf)– Full and Log backups (.bak .trn)

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SQL Server Tests

• SQL Server Space Allocation Policy• Perfect for Hitachi Dynamic Provisioning• Reduces riskCREATE DATABASE trusqlONPRIMARY ( NAME = trusql1,

FILENAME = 'S:\V\B906\trusql1.mdf',SIZE = 420MB,MAXSIZE = 42000,FILEGROWTH = 42)

LOG ON ( NAME = trulog1,FILENAME = 'S:\V\B907\trulog1.ldf',SIZE = 42MB,MAXSIZE = 10000,FILEGROWTH = 42)

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SQL Server Tests

SQL Server DATA (Large Initial Size)

0100200300400500600700800

0 500 1000 1500 2000

MB

HDP WIN

420MB +Initial FS overhead

Insignificant over use

Soon keeps in step.

Alignment different.

SQL Server does format space

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SQL Server Tests

SQL Server DATA (42MB INCREMENT)

500

600

700

800

900

1000

1100

MB

HDP WIN

Still no deviationAvg 95MB

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SQL Server Tests

SQL Server DATA

0

500

1000

1500

2000

2500

3000

0 2000 4000 6000 8000 10000 12000 14000 16000

Records Added

MB

HDP WIN MODEL

Remains parallel

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SQL Server Tests

SQL Server LOG

0500

10001500200025003000350040004500

0 2000 4000 6000 8000 10000 12000 14000 16000

Records Added

MB

HDP WIN MODEL

Required steady state.

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SQL Server Best Practice

• Database (.mdf)– Good, base size on planned initial use– Increment base on days growth Could be as low as 42MB

• Online logs (.ldf)– Good, base size on planned initial use– Increment base on days growth

• Log file backups (.trn)– Unconstrained, either:

• don’t over provision• use dynamic partition expansion• use static provisioning

• None of this is significantly different from normal SQL Server Management

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Oracle Tests

• Ported SQL Server scripts; added Oracle Physical SchemaeAutomatic Storage Management (ASM)• ASM is both a volume manager and a specialized file system.

Can dynamically add/remove/expand storage objects.• ASM does not conflict with: Hitachi storage, virtualization or

Hitachi Dynamic Provisioning. They complement. Some overlap – which gives more options.

• Hitachi/Oracle ASM recommendations for layoutOCFS2• Oracle Cluster File System – version 2• Shared file system for RAC

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Tablespace configuration

CREATE TABLESPACE "VS1“;DEFAULT: SIZE 100M AUTOEXTEND ON MAXSIZE UNLIMITED

CREATE SMALLFILE TABLESPACE "VS1" DATAFILE '+VS1DG' SIZE 42M AUTOEXTEND ON NEXT 42M MAXSIZE 1GEXTENT MANAGEMENT LOCAL SEGMENT SPACE MANAGEMENT AUTO LOGGING DEFAULT NOCOMPRESS;

CREATE TABLE TESTVS1 (COL1 number(10) NOT NULL, COL3 number(10) NOT NULL)TABLESPACE “VS1" STORAGE (INITIAL 1M);

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ASM: Tablespaces

0

100

200

300

400

500

600

700

800

900

MB

DG Pool TableChanged tablespace to compression on

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ASM: Tablespaces

Multiple Tables per TableSpace

0

50

100

150

200

250

300

350

400

450

500

MB

DG Pool Table DGMultiple TableSpaces per DiskGroup and drop/re-create TableSpaces

0

50

100

150

200

250

300

350

400

450

500

DG Pool Table DG

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ASM: Archive Redo Logs

0.0

0.5

1.0

1.5

2.0

2.5

3.0

GB

Pool Archive Redo

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Oracle without ASM: factors

ASM

Switch, Cache, Virtualize, Dynamic Provision

Pools

VMLVLV

A

VM raw

A

FS

A

VMLVLV

VM FS

A A

CFS

A

DP-Volumes

Raw

A

DG

Far too many choices:Database version (20)Base OS (17+)OS version (8+)Volume Manager (0-2)File System (0-22)Oracle configuration parameters (30+)

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Oracle Cluster File System – OFCS2

0.0

0.5

1.0

1.5

2.0

2.5

3.0

3.5

4.0

4.5

5.0

GB

Pool Table DG Difference

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Oracle guidelines

• External redundancy only • Create tablespace

– minimize initial allocation• Create table

– minimize initial allocation

• NEXT=growth for a period – day (or week/month)– Ideally multiples or integer divisor of 42MB page.

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Replication products

• ShadowImage and Volume Migrator today. Internal and external storage. Copy-On-Write, TrueCopy and Universal Replicator in development.

• Works well with Hitachi Dynamic Provisioning. Some rules, but they’re obvious.

• Useful configuration: HDP to HDP.• Tested with Hitachi Protection Manager and it works well

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General recommendations

• Avoid tools which write all the disk: – low level unix media format or check– volume level copy tools (dd)

• Don’t software RAID-1 mirror or RAID-5

• Use file level copy• Defragmentation – not recommended

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Hitachi Dynamic Provisioning Tools

• Raid Manager:raidvchkdsp –g HDP –v aouGroup PairVol Port# TID LU Seq# LDEV# Used(MB) LU_CAP(MB) U(%) T(%) PID

HDP MDF CL6-B-1 18 35 10044 b906 2814 93750 1 70 9

HDP LDF CL6-B-1 18 36 10044 b907 4032 93750 1 70 9

HDP AUX CL6-B-1 18 37 10044 b908 8442 93750 1 70 9

• Hitachi Device Manager– Create, delete, increase Pools– Create DP-VOLs, V-VOL Groups– Alerts

• Hitachi Tuning Manager– Trending– Trended alerts– Reports– Performance and capacity

Pool 1% used Pool 9

PoolThreshold

Max size as seen by OS.

PoolAllocated to Device

Device Details

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Performance with Hitachi Dynamic Provisioning

• Generally all good news• Both modeling and testing seems to show that there is little or no

difference in back-end requirement.• But can benefit from leveling• Small reduction in peak front-end performance but is less often a

bottleneck• Your Hitachi Representative has modeling tools to assist

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Thank you

• Call to action:– Hitachi Dynamic Provisioning is easy to understand and use.– If you have a Universal Storage Platform V or Universal Storage Platform

VM, evaluate it– Have a go at quantifying the cost savings

• More information:– “Guidelines for the Use of Hitachi Dynamic Provisioning Software with the

Microsoft® Windows Operating System and Microsoft SQL Server 2005, Microsoft Exchange 2003 and Microsoft Exchange 2007”

– “Guidelines for the use of Hitachi Dynamic Provisioning Softwarewith Oracle® Databases and Automatic Storage Management”

– “Oracle Database 10g Automatic Storage Management Best Practices with Hitachi Replication Software on the Hitachi Universal Storage Platform™Family of Products”, co-authored by Oracle and Hitachi Data Systems

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Upcoming WebTech Sessions:

We have several additional WebTech’s planned this year

06 February: Virtualizing Storage to Gain Maximum Benefit from a VMware Environment

20 February: Replication Management19 March: Hot Spot Management with Hitachi Tiered Storage Manager 23 April: Creating Tuning Manager Reports

We will be adding additional sessions based upon participant requests.

• Please go to www.hds.com/webtech next week for the a link to the recording, presentation, and Q & A in addition to registering for upcoming WebTechs.

Questions/Discussion

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Thank You

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