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1 TimeFinder Fundamentals


This course, developed by EMC Education Services, builds on the Proven Professional Associate curriculum and certification by exploring the features and capabilities of core EMC technologies and products for all markets; encompassing tiered storage products, backup and recovery systems, virtualized datacenter products, resource management and information security products, and EMC Proven Solutions.



Upon completion of this course, you should be able to identify TimeFinder concepts and architecture, differentiate TimeFinder solutions, describe operations, identify management software offerings, and describe the TimeFinder business benefits and considerations.



This module covers TimeFinder local replication benefits and TimeFinder usage as a point-in-time business tool. It also provides an overview of TimeFinder’s application set, lists the architectural components, and describes the TimeFinder product family.



TimeFinder is a family of products that enable businesses to provide multiple point-in-time copies of data to distribute business tasks. This allows for simultaneous action of previously sequential business tasks. An example is the ability to back up a point-in-time copy of critical data while production operations continue on the source data.

In today’s IT environments, it is critical to have choice and flexibility when building local replication solutions in order to match the right product to your service-level requirements. The TimeFinder family of products offers the broadest choice of alternatives, from full-volume mirrors and clone copies, to space saving snapshot copies. Understanding the features and functions of each of the TimeFinder product family options is imperative for identifying the appropriate solution.



Local replication can significantly enhance current business and technical operations by providing access points to production data for parallel processing activities like backups, disk-based recovery after logical corruptions, and creating test environments for faster application time-to-revenue.

The Recovery Point Objective (RPO) is the point-in-time to which systems and data must be recovered after an outage; for example, the end of the previous day’s processing. RPOs are often used as the basis for the development of replication and backup strategies and as a determinant of the amount of data that may need to be recreated after the systems or functions are recovered.

The Recovery Time Objective (RTO) is the period of time within which systems, applications, and functions must be recovered after an outage; for example, one business day. RTOs are often used as the basis for the development of recovery strategies, and as a determinant as to whether or not to implement the recovery strategies during a disaster situation.



TimeFinder allows storage-based information users to make more effective use of their most valuable resources by enabling parallel information access. In contrast to traditional sequential information access, TimeFinder eliminates the need to quiesce an application for backup. This provides tangible benefits to businesses, including accelerated upgrades.

TimeFinder enables application upgrades to quickly identify and remedy problems, minimize risk, and reduce production downtime. TimeFinder eliminates the backup window to high availability demand systems. TimeFinder can also shorten maintenance windows, minimize infrastructure costs, and improve service levels.



The TimeFinder family has several different solutions to help you meet your service-level requirements, while providing very powerful local replication capabilities.

Let’s take a look at what the TimeFinder family delivers. First is its massively parallel high performance and unsurpassed RPO and RTO with minimal server impact.

TimeFinder easily integrates into industry-leading applications, such as Oracle, Microsoft, VMware, SAP, and IBM. This is a result of the integration efforts as well as EMC partnerships with these major application vendors. TimeFinder is highly recommended with remote replication solutions like SRDF (Symmetrix Remote Data Facility) to increase application availability and improve test/development capabilities and disaster restart requirements.

TimeFinder is the solution Symmetrix customers rely on for business continuity locally, in the array, and in the data center.



Each TimeFinder product (TimeFinder/Clone, TimeFinder/Snap) has its own distinct architecture and operational characteristics. These attributes are essential when addressing the wide scope of customer data replication requirements. The components that make up each TimeFinder solution are listed here. TimeFinder architectural components are presented at a high level within the next few slides.

VP Snap leverages TimeFinder/Clone technology to create space-efficient snaps for thin devices by allowing multiple sessions to share allocations within a thin pool. VP Snap provides the efficiency of snap technology with improved cache utilization and simplified pool management. With VP Snap, tracks can be stored in the same thin pool as the source, or in another pool of your choice.



Regardless of the replication technology that is being implemented, the Symmetrix storage array uses “Track Table” technology that creates a record of the data that has been changed. Using this information is what drives the movement or resynchronization of data back and forth from the source and/or target devices.

This technology is employed regardless of whether the data is located in a single array or across multiple arrays. The Track Table is the underlying enabler for all Symmetrix storage array-based data-mobility applications and technologies.



This slide describes the EMC TimeFinder family of products for the VMAX 20K/VMAX and VMAX 40K arrays. The TimeFinder family of products includes Symmetrix local replication solutions designed to non-disruptively create point-in-time copies of critical data. You can configure backup sessions, initiate copies, and terminate TimeFinder operations from mainframe and open systems controlling hosts using EMC Symmetrix host-based control software.

The TimeFinder local replication solutions include TimeFinder/Clone, TimeFinder/Snap, and TimeFinder VP Snap. TimeFinder/Clone creates full-device and extent-level point-in-time copies. TimeFinder/Snap creates pointer-based logical copies that consume less storage space on physical drives. TimeFinder VP Snap provides the efficiency of snap technology with improved cache utilization and simplified pool management.

Each solution guarantees high data availability. The source device is always available to production applications. The target device becomes read/write enabled as soon as you initiate the point-in-time copy. Host applications can therefore immediately access the point-in-time image of critical data from the target device while TimeFinder copies data in the background.

TimeFinder includes the following features:

• Supports RAID 1, RAID 5, RAID 6, and RAID 10 protection schemes,

• Provides restore capabilities,

• Provides incremental re-synchronization between the source and the target,

• Supports virtual provisioning, and is

• Tightly integrated with SRDF



This slide describes the EMC TimeFinder for VMAX 10K/VMAXe family of products.

The TimeFinder family of products are Symmetrix local replication solutions designed to non-disruptively create point-in-time copies of critical data. You can configure backup sessions, initiate copies, and terminate TimeFinder operations using EMC Symmetrix host-based control software.

TimeFinder local replication solutions include TimeFinder/Clone and TimeFinder VP Snap. TimeFinder/Clone creates full-device point-in-time copies. TimeFinder VP Snap provides the efficiency of snap technology with improved cache utilization and simplified pool management.

Each solution guarantees high data availability. The source device is always available to production applications. The target device becomes read/write enabled as soon as you initiate the point-in-time copy. Host applications can therefore immediately access the point-in-time image of critical data from the target device while TimeFinder copies data in the background.

TimeFinder includes the following features:

• Supports RAID 1, RAID 5, and RAID 6 protection schemes,

• Provides restore capabilities,

• Provides incremental re-synchronization between the source and the target,

• Supports virtual provisioning, and is

• Tightly integrated with SRDF



With all the choice and flexibility in making TimeFinder family replicas, how do you know which type to use and when? It is a matter of balancing customer needs and mapping them back to a few key areas: performance, availability, functionality and economics.

Pointer-based images are not physical copies of your information; they are logical views of the original information based on the time the image was created. Snapshots and snaps are created in seconds and can be retired when no longer needed.

In contrast to a full data copy, a snapshot uses only a fraction of the original space. Multiple snapshots can be created to suit the needs of multiple business processes. Secondary servers see the snapshot as an additional mountable disk volume. Servers mounting a snapshot have full read/write capabilities with the snapshot data.

TimeFinder/Snap multi-virtual sessions allow up to 128 virtual point-in-time copies. TimeFinder/Snap sessions on Symmetrix VMAX 40K systems always use multi-virtual mode.

VP Snap leverages TimeFinder/Clone technology to create space-efficient snaps for thin devices by allowing multiple sessions to share allocations within a thin pool. VP Snap provides the efficiency of snap technology with improved cache utilization and simplified pool management. With VP Snap, tracks can be stored in the same thin pool as the source, or in another pool of your choice.



This module covers TimeFinder/Clone, clone operations, clone components, cascaded clone functionality, and TimeFinder/Clone functional capabilities.



TimeFinder/Clone is a pointer-based, full-copy product for Open Systems and Mainframe environments. It enables the creation of point-in-time copies that can be used for backups, decision support, data-warehouse refreshes, or any other process that requires parallel access to production information.

Clones can be protected using any type of supported protection scheme, including RAID 5 and RAID 6. They do not require a Symmetrix mirror position. You can create up to 16 active clones of a single source volume, all of which are immediately available for both read and write access.

A differential clone session uses two (2) copy sessions, therefore, you can only have a maximum of eight (8) differential clone sessions. (A differential clone operation copies only those device tracks that have changed.)

TimeFinder/Clone also includes a “NOCOPY” option, which enables you to perform a copy process only when the actual data is requested. As with all TimeFinder family products, TimeFinder/Clone supports the TimeFinder/Consistency Groups option to ensure data consistency between volumes and across Symmetrix systems.

TimeFinder/Clone is ideal when high performance, RAID 5 and RAID 6 protection, and highly functional point-in-time copies are required.



The TimeFinder/Clone creation and implementation process consists of the following operations.

1. Create: creates a relationship between source and clone.

2. Activate: the Clone is now active and available immediately for read/write access and the production I/O is processed against standard.

3. Establish: “Creates” a relationship between the source and target and “Activates” the clone session.

4. Recreate/Activate: the Clone is re-attached to Standard for new point-in-time copy, which is incremental.

5. Restore: the Clone is re-attached to Standard: incremental or full restore performed.

6. Terminate: causes the target host to lose access to clone, and removes clone.

Each step is a critical component of a disk-based, local protection and recovery solution.



When you use the copy option, the TimeFinder/Clone session copies all of the source device tracks to the target device. The copy process starts when you activate the session (initiate the point-in-time copy) and completes when all of the source device tracks are copied to the target device and no protected tracks are left. You will typically use the copy option to create a full source device copy on the target device (gold copy) and keep data on the target device intact for recovery purposes. You can also use the copy option if you need to make the full-device point-in-time copy available to another host. The other host can then access the target device while the production host continues to access the source device.

The TimeFinder/Clone copy options are:

Copy on access: The track is copied the first time a track on the source device is written to, or a track on the target is accessed. This is the default mode of operation for TimeFinder/Clone.

Full background: This option copies data as a low priority task, whether the data is accessed or not. This mode is enabled after activation of the clone session.

Pre-copy function: Starts copying tracks in the background, before the clone session is activated.



TimeFinder/Clone can use Standard or BCV (Business Continuance Volumes) for source and target devices, as long as all the devices are the same size and emulation type (FBA or CKD).

The target of a copy operation is a Symmetrix storage array clone. Copying to a clone can be immediate, as with PreCopy, or deferred, as with CopyOnAccess.

Copying occurs when there are writes to the source device or reads/writes to the target device. The clone pair state remains CopyOnAccess until you terminate the copy session, or until all tracks have been accessed. This is the default option for any Open Systems environment.

MODE(COPY) is the default in the Mainframe environment, and specifies that the source to target background copy should begin immediately. To get the equivalent of CopyOnAccess on the Mainframe, you would use the MODE(NOCOPY) parameter command.



The TimeFinder/Clone restore command copies target data to another device or back to the original source device.

In the case of a Full Restore, the original session terminates and a copy session to the target of the restore starts. In the case of an Incremental Restore, the original session terminates and an incremental copy session back to the original source device will start.

To support a Full or Incremental operation, the session must have been created with the differential option during the create session, and the target device must be in a fully copied state.



With Enginuity 5874 and beyond, TimeFinder/Clone supports Thick to Thin replication, allowing customers to take advantage of virtual provisioning by providing the ability to quickly move an application’s data from standard or thick volumes to virtually provisioned storage (Thin devices) within the same array.

Data can also be moved from Thin devices to standard devices (Thin to Thick) for situations where the space efficiencies and rapid provisioning of virtual provisioning is no longer required, or where specific applications may be better suited to standard devices. During the replication operation, disk extents (chunks) marked as “Not Written By Host” (NWBH) are automatically detected and will not be copied to the thin device.

A key consideration for Thick to Thin replication is ensuring the thin pool has an adequate amount of space to accommodate the standard device.

The replication does not disrupt hosts or internal applications during the copy process, but the user will need to handle the application and host addressing of the new devices. During the cloning process, replications of the standard devices remain in full operation.

The source and target of the replication operation can also be different RAID protection levels. An unprotected device can be replicated to a RAID protected device, but you cannot replicate a protected volume to an unprotected volume. TimeFinder/Clone support for Thick to Thin replication is supported on EFD, Fibre Channel drives, and SATA drives for FBA emulations.



Full-Device TimeFinder/Clone supports cascaded operations. The cascaded clone capability allows you to create two full device TimeFinder/Clone sessions using the same device as a source device and as a target device. You can then run both sessions concurrently as long as you activated the copy process sequentially to preserve the copy direction.

Clone from clone target (both sessions are cascaded clone) shows how cascaded sessions are accepted from left to right. You can activate Session 1 to copy from device A to device B. Then, you can activate Session 2 to clone device B to device C. If your copy direction is A=>B=>C, you can activate session B=>C, but only after you activated Session 1 from A=>B.

Cascaded clone is supported with VP Snap with some restrictions. Refer to the EMC Solutions Enabler TimeFinder Family CLI Product Guide for additional details.



The table here highlights some of the major specifications and limitations of TimeFinder/Clone. The slide also highlights TimeFinder/Clone compatibility with other EMC software products.



This module covers an overview of TimeFinder/Snap, snap operations, snap components, and using TimeFinder/Snap for backups. It also covers TimeFinder/Snap and Clone operations with Thin Devices (TDEV’s) and TimeFinder/Snap restore operations and functional capabilities. TimeFinder/Clone and TimeFinder/Snap support for virtual provisioning is discussed.



TimeFinder/Snap creates space-saving, economical, logical point-in-time images or snapshots. The snapshots are not full copies of data; they are logical images of the original information, each based on the time the snapshot was created. A snapshot is simply a view into the data that was frozen at the time of activation.

A set of pointers to the source-volume data tracks is instantly created on activation of the snapshot. This set of pointers is addressed as a logical volume, and is made accessible to a secondary host that uses the point-in-time image of the underlying data.

TimeFinder/Snap supports:

• Open systems and Mainframe data volumes,

• Up to 128 concurrent snaps of a single-source volume,

• Full-function access to the snap. That is, the snap may also be updated, with the updates residing in the Save area, and

• RAID 1, RAID 5, and RAID 6 protection

In many situations, you’ll find yourself trying to support multiple service levels with a single solution. TimeFinder/Snap allows you to complement existing TimeFinder family environments, fulfilling multiple service level requirements while balancing the economics of the solutions.



TimeFinder/Snap supports open systems and mainframe data volumes. There can be up to 128 concurrent snaps of a single source volume in Open Systems and Mainframe environments, provided Multiple Virtual Snap option is enabled, otherwise eight (8) concurrent snaps in the Open Systems and Mainframe environments.

Note: TimeFinder/Snap sessions on Symmetrix VMAX 40K systems always use multi-virtual mode.

There is full function access to the snap. That is, the snap may also be updated with the updates residing in the save area.

Save devices contain the original tracks that were changed as a result of a first copy on write to a source device, or a new write to a virtual device during a virtual device copy session. The Symmetrix storage array supports the creation of multiple named SAVE device pools, allowing commands to use a specific pool.

EMC Snap allows the user to complement existing TimeFinder solutions, such as Clone and Mirror, fulfilling multiple service-level requirements while balancing the economics of the solutions.



A SAVE device is a Symmetrix device that is not accessible to the host, and can only be accessed through virtual devices that point to it. SAVE devices provide pooled physical storage and are configured with any supported RAID scheme. SAVE devices cannot be metadevices. They store either source data copied to the SAVE pool during the TimeFinder/Snap session, or updates from the host mapped to the virtual device. TimeFinder/Snap operations are designed to create point-in-time copies of the source device when only a fraction of the source device changes over time. The SAVE device pool storage capacity can be much smaller than the capacity of the source device.

Note: Source, Virtual and SAVE devices have to be configured with the same device emulation type (FBA or CKD).

This slide provides an overview of how a TimeFinder/Snap device works, including:

• The creation of the snap through a copy session,

• Copying the original source data to a “save” device, and

• Setting up a tracking relationship between the source device and its updated save device, which keeps data in place and current between both the source and the save device.



The TimeFinder/Snap creation and implementation process consists of the following operations.

1. Create: creates relationship between standard and virtual device.

2. Recreate: creates a new Point-In-Time of the standard.

3. Activate: activates the copy session and starts the copy on first write mechanism, and production I/O is processed against standard.

4. Establish: “Creates” a relationship between the source and target and “Activates” the clone session.

5. Restore: copies tracks from the virtual device to the standard or other device.

6. Terminate: causes the target host to lose access to data pointed to by the virtual device.

Each step is a critical component of a disk-based local protection and recovery solution.

Prior to Enginuity 5874, taking a new point-in-time TimeFinder/Snap copy required terminating the previously activated snap session between the source volume and the target virtual volume (VDEV). The Recreate operation now allows a new point-in-time without terminating the previous TimeFinder/Snap session. After activation of a Snap session, the session can be recreated and then activated, as when new point-in-time images are required.



The Production view is a standard view into an active production volume from the host’s perspective. EMC Snap creates the same type of view into the production data at a specific point-in-time. The cache-resident pointers maintain the point-in-time nature of the snapshot as unchanged data is “shared” with the production view, and changed data is temporarily collected in the pre-defined save area.

A best practice for snap does not require more than 20% of the source volumes’ capacity in the save area.

TimeFinder/Snap sessions are also referred to as virtual sessions. Like TimeFinder/Clone sessions, virtual sessions use a protection session on the source device. You can run only one type of a virtual device session on a single source device.

Note: Since a virtual session is associated with a point-in-time copy and a particular virtual device, you need to keep a virtual session active as long as you need its snapshot copy. By terminating a virtual session, you remove the associated point-in-time copy because Enginuity automatically releases the storage space in the associated SAVE device pool.



This is an example of a backup operation from a snapshot. The snapshot gets created and the backup host mounts the snapshot and performs the backup against the snapshot.

It is important to note that the backup runs a sequential read process against the snapshot, so the production application may encounter some performance contention during the backup, due to the fact that the snapshot and production host are both looking at many of the same spindles.



When handling writes to the production data, TimeFinder/Snap uses a process called Copy on First Write. As an example, let’s say a snapshot is active on the production volume. When a host attempts to write to the data on the production volume, the original Track C is first copied to the save area, then the write is processed against the production volume. The track pointers are maintained for consistency, that is, the point-in-time copy of the data of the ongoing snapshot.

The copy on first write process is as follows:

1. A write from the host is sent to the source device during the copy session. The track is marked write pending.

2. A pre-updated image of the changed track is copied to a SAVE device.

3. The host I/O is completed.

4. The track pointer on the virtual device will then be updated to point to the data on the SAVE device.



Because of the delay of operation when moving the original track on copy on first write, enhancements have been made to TimeFinder/Snap. “Avoiding Copy On First Write” provides for improved host performance response times, making the use of space-saving snap devices extremely appealing for point-in-time operations.

The process with TimeFinder/Snap Avoid Copy on First Write is as follows:

1. Write I/O from host to Symmetrix with new data track cache slot marked as version write pending.

2. New write I/O completion immediately acknowledged back to the host application.

3. Older data track is read from disk and marked write pending to Save Pool; new write version indicator cleared and new write marked write pending to Standard.

4. New write and older data track marked write pending in cache are both de-staged and the VDEV pointer is updated.



Here is an example of an incremental restore operation back to the original standard device. When the restore is initiated, the host application must be offline so as not to create the potential for data corruption during the restore process.

The restore completes after all the collected changed data in the save area for that particular snapshot is copied back to the standard device. You can also restore to a BCV device when it is in split state.



From Enginuity 5874 onward, the TimeFinder/Clone relationship can be maintained while a restore occurs from a TimeFinder/Snap to a production volume that is a source volume for both the TimeFinder/Snap and TimeFinder/Clone volume.



Thin devices are cache only devices. TimeFinder/Snap supports snapping a Thin device to a virtual device. All operations are supported. TimeFinder/Clone supports cloning a Thin source device to a Thin target device.

For Mainframe, both FBA Thin and CKD Thin devices are supported with TimeFinder/Clone or TimeFinder/Snap. CKD volumes can only be snapped to CKD volumes of the same size or larger. FBA volumes can only be snapped to FBA volumes of the same size.



The table illustrated here highlights some of the major specifications and limitations of TimeFinder/Snap. This slide also highlights TimeFinder/Snap compatibility with other EMC software products.



This module provides an overview of the TimeFinder VP Snap environment. This module also lists VP snap limitations and restrictions.



VP Snap leverages TimeFinder/Clone technology to create space-efficient snaps for Thin devices by allowing multiple sessions to share capacity allocations within a Thin pool. VP Snap provides the efficiency of Snap technology with improved cache utilization and simplified pool management. With VP Snap, tracks can be stored in the same thin pool as the source, or in another pool of your choice. VP Snap sessions copy data from the source device to the target device only if triggered by a host I/O. Read I/Os to protected tracks on the target device do not result in data being copied.

This functionality is available for all Symmetrix VMAX models. Up to 32 snaps per VP source can be created. TimeFinder VP Snap is efficient because there is no separate SAVE pool area. It is the same virtual pool as the source devices.

TimeFinder VP Snap is supported with Enginuity 5876. This feature provides the ability for multiple Clone Nocopy sessions to target Virtual Provisioned volumes (TDEVs) that can share allocations within the same Thin Pool, thus reducing the space needed for storage of the tracks saved, in a manner that is similar to the use of TimeFinder/Snap pools. It further provides the ability to perform Incremental Restores from these VP Snap sessions.

TimeFinder Fundamentals 37


Here are some VP Snap Restore limitations and restrictions that you need to be aware of. For a complete set, please refer to EMC TimeFinder user guide Restore Limitations include:

• Only one restore allowed at a time, • Session is charged against source volume, • Session must be fully copied, and • Original CopyOnWrite session is preserved

Restrictions include: • Only terminate command allowed after restore, • Clone split not supported for restored session, • Restore from another session is not allowed, and • Clone Larger Target is not supported



This module covers the TimeFinder management tools, TimeFinder integration with SRDF, and the Consistent Split functionality.



Unisphere for VMAX supports all the new Enginuity higher functionality. Unisphere and Symmetrix Performance Analyzer recognize and honor the Symmetrix Management Console eLicense. Unisphere for VMAX provides users with the same EMC standard look and feel. Unisphere for VMAX is contextual and simple to navigate. With Unisphere, users can easily and rapidly manage and monitor all Symmetrix VMAX TimeFinder features.



The SYMCLI TimeFinder component extends the basic SYMCLI command set to include TimeFinder or business continuance commands that allow you to perform control operations on device pairs within the TimeFinder environment.

The TimeFinder CLI command set provides functionality for general monitor and control operations using clone and snap copy sessions.



EzSM (EMC z/OS Storage Manager) performs TimeFinder/Mirror functions against Standard and Business Continuance Volumes (BCVs) within a Mainframe environment. Using the EzSM interface, you can perform standard TimeFinder/Mirror operations, such as:

• Establish • Query • Re-Establish • Restore, and • Split

EzSM also allows you to perform TimeFinder/Snap operations, such as: • Activate • Config Pool • Define Source Volume • Delete Group • Query Group • Restore Volume, and • Stop Snap Volume



EMC ProSphere provides end-to-end views across your virtual and physical environments. From virtual guest down through storage, just two clicks of the mouse, and we can search on a host and display end-to-end topology. EMC ProSphere provides views to understand TimeFinder usage and trends.

EMC ProSphere can monitor alerts across the total Symmetrix, supporting both local and remote environments, and drill-down to quickly understand their impact.



Another management tool is EMC Replication Manager. It is an application that automates, simplifies and manages disk-based replications by using TimeFinder operations (supporting both Clone and Snap functionality).



TimeFinder is closely integrated with the EMC Symmetrix Remote Data Facility (SRDF). The SRDF family of products are Symmetrix-based disaster recovery, parallel processing and data migration solutions. The SRDF family of products is based on active remote mirroring and dependent-write consistent copies of data maintained at one or more remote locations. A dependent-write is a write I/O request that cannot be issued by an application until a prior, related write I/O request is completed. Dependent-write consistency is required to ensure transactional consistency once the applications are restarted at the remote location.

SRDF solutions require at least two arrays (the primary array and the secondary array). The arrays can be located at sites in the same room, in different buildings within the same campus, or many kilometers apart.

Depending on the type of remote mirroring, the SRDF solutions operate in synchronous mode (SRDF/S), asynchrones mode (SRDF/A), or adaptive copy mode.

The advantage here is that every production transaction is replicated across the RDF link. This provides the organization with a remote, up to date replicated copy. On the remote array, a TimeFinder Clone or Snap session will provide the organization with a point-in-time copy for Reporting, Application Testing, or Development. The Clone or Snap replica will not impact production performance.



When you create a point-in-time image across multiple devices, it is imperative that the entire set of logical volumes be captured at the exact same time.

One way to achieve this is to shut down (totally quiesce) an application so that no I/O occurs while you create the sessions. This would obviously be a problem in today’s application environments.

The EMC solution to the problem is called Enginuity Consistency Assist, or ECA. When you create a set of sessions and invoke Enginuity Consistency Assist, the Symmetrix storage array aligns the I/O of those devices and halts all I/O from the host systems, very briefly, much faster than the applications can detect, while it creates the sessions.

It then resumes normal operation without any application impact.



The device groups and composite groups are entities you can create and use to manage and control Source and Target pairs.

You can create a composite group to control a set of device pairs that span multiple arrays. A composite group provides greater flexibility than a device group, which can define devices only on a single array.

The Symmetrix storage device groups, or composite groups, must be created on the controlling host for the targets to be consistently split.

Composite groups are used in conjunction with Consistent Splits to create a re-startable database application.

In a Mainframe environment, device ranges can be specified in the SPLIT command, or GNS Groups can be created and used to control multiple device pairs that will ensure consistency.



TimeFinder/CG is based on the Enginuity Consistency Assist (ECA) feature that enables you to create a consistent point-in-time image across multiple devices. This is necessary for tasks such as backing up all of the devices that belong to a particular application or backing up multiple devices distributed across multiple sites.

When you use TimeFinder/Clone to create a consistent point-in-time copy across multiple devices, you need to ensure that the point-in-time copy starts simultaneously across a range of devices that participate in the process. To accomplish this, you need to block host I/Os across multiple devices when you activate multiple TimeFinder/Clone sessions. The time interval during which the host I/Os are blocked is also referred to as the ECA window.

The TimeFinder/Consistency Group (TimeFinder/CG) feature guarantees that a consistent point-in-time image of data written across multiple local devices (TimeFinder source devices) is created on another set of local devices (TimeFinder target devices).

The SRDF/Consistency Group (SRDF/CG) feature is used in SRDF/S solutions to guarantee that a dependent-write consistent image of production data on the R1 devices is created across the SRDF links.

TimeFinder/CG and SRDF/CG both use the Enginuity Consistency Assist infrastructure. By using TimeFinder/CG in an SRDF configuration, you can create dependent-write consistent local and remote images of production data across multiple devices and Symmetrix arrays.



This module covers TimeFinder “User Case” considerations.



As EMC’s customers work to support their overall business, they have to be particularly focused on information storage and management. The fact that data continues to grow at a robust rate shows that they will always have a dramatic growth in information.

There are new requirements around compliance, and new levels of protection and recovery. It is not just about backups; it also includes how customers can restore their application and get their business back online quickly and efficiently.



The key benefits of the TimeFinder family include:

• Continued access to applications, even in the event of a restore operation,

• The ability to create up to 16 TimeFinder volumes from a single standard volume,

• The ability to create point-in-time snapshots using less disk space, without compromising local restoration capabilities, and

• VP Snap leverages TimeFinder/Clone technology to create space-efficient snaps for thin devices by allowing multiple sessions to share allocations within a thin pool.



Combining SRDF with TimeFinder gives the business the advantage that every production transaction can be replicated across the RDF link. The scenario in this slide is showing an Oracle production environment being replicated. This scenario could be used to support other applications, such as SQL Server, or Exchange.

The key here is production is being replicated, and with TimeFinder Clone or Snap, a point in time copy can be created for reporting, resulting in no performance impact on production. The above user case also gives the business the ability to back up a point-in-time copy of critical data while production operations continue. This is just a couple of TimeFinder user case examples that can be implemented.



When to use TimeFinder/Clone or TimeFinder/Snap should be discussed in the context of which one best fits the business requirements. Both the RPO and the RTO objectives should be understood when considering which replication solution to implement.

TimeFinder/Clone may be a better fit if the business needs full point-in-time copies. Also, Clone should be considered where advanced replication utilizing SRDF is being implemented. Another factor is the time requirements for your replica. Longer activated point-in-time copies are better fits for TimeFinder/Clone.

TimeFinder/Snap proves beneficial where short-term, point-in-time copies meet the business requirements. Also, TimeFinder/Snap should be considered when a small Recovery Point Objective can be implemented.



This slide shows the key points covered in this course. Please take a moment and review the them.

This concludes the training. Proceed to the course assessment on the next slide.


Documents

Welcome to TimeFinder Fundamentals....2016/07/04 · Use, copying, and distribution of any EMC software described in this publication requires an applicable software license. EMC2,