Users Guide

• Cloning the template volume, which results in a new template volume

NOTE: Snapshots and replication of template volumes are not supported.

Robust Data Recovery

ASM/ME enables you to implement different data recovery strategies by recovering data directly from a Smart Copy. The principal

methods of recovering data from Smart Copies are:

• In-Place Recovery—A full recovery method that restores all data in a volume. You can use this recovery option for snapshot Smart

Copies of generic data volumes or for application components. Application components might consist of Exchange mailbox databases,

SQL Server databases, or Hyper-V virtual machines.

• Selective Component Recovery—A selective restore of files or components. Selective restore is supported only for components

belonging to certain applications. Some constraints apply to recovery methods and supported Smart Copy types. These constraints

are identified in the section for each supported application.

• Manual Recovery—You can use ASM/ME to mount a snapshot Smart Copy and manually copy over data from the mounted Smart

Copy.

Think-Provisioning a Volume

On a PS Series group, the storage for a thin-provisioned volume is allocated incrementally as the volume uses more space. The full amount

of space reserved for the volume is not immediately allocated when the volume is created. Over time, however, as data is written to thin-

provisioned volumes, they lose their space efficiency because the group has no way to release storage that is no longer in use by the

volume (for example, because files were deleted).

HIT/Microsoft includes tools for managing thin-provisioned volumes on PS Series groups running firmware version 7.0 or later. These tools

are available on all supported Microsoft operating systems.

• You can thin-provision a volume through the ASM/ME GUI, both as a one-time operation and through schedules. See About Thin-

Provisioning Volumes in HIT/Microsoft and Schedules for Thin-Provisioning for more information.

• The Host Integration Tools include a command-line utility called eqlrethin.exe (see the Host Integration Tools for Microsoft

Installation and User’s Guide).

• The Dell EqualLogic PowerShell Tools include a cmdlet called Invoke-RethinEqlVolume. See the Dell EqualLogic PowerShell

Tools Reference Guide for detailed information about this cmdlet.

Windows Server 2012 or later automatically performs thin-provisioning. Typically, Windows thin-provisions the volume soon after a file is

deleted.

For replicated volumes (including SyncRep), Dell recommends that you disable the SCSI unmap support in Windows Server 2012 or later.

See the Dell EqualLogic Group Manager Administrator’s Guide for more information, which describes the effects of SCSI unmap

operations.

NOTE:

When you disable unmap support, the Host Integration Tools thin-provisioning feature does not work. To thin-

provision a volume, you must use the Windows Disk Optimization tool.

SAN Data Copy Offload

ASM/ME uses SAN Data Copy Offload to perform its selective restore operations. SAN Data Copy Offload is a Dell EqualLogic API that

accelerates file copy operations by using SCSI Extended Copy commands.

SAN Data Copy Offload frees up server resources and decreases the time it takes to perform selective restores. For example, assume

multiple volumes are residing on a PS Series group. If those volumes are mounted on a Windows server, copying a file or directory from

one volume to another formerly required the host to read the relevant data from one volume, and then write that data to the destination

volume.

With SAN Data Copy Offload, the host sends the SCSI Extended Copy command to the volume, and the data is copied to the destination

volume within the group itself, thus consuming far less CPU bandwidth and memory.

If the SCSI Extended Copy operation fails for any reason, the standard copy command is automatically used. You do not need to perform

any tasks to enable this behavior.

Introduction to ASM/ME