PerfectStorage System Requirements

Hardware

A storage controller that supports either SCSI UNMAP or zero detect to reclaim thin provisioned storage


Please see Will PerfectStorage work with my storage controller? for more information.

Virtual Environment

If you in a virtual environment then a hyper-visor that supports SCSI UNMAP or zero detect is required in order to reclaim thin provisioned virtual disk drives.


Please see Will PerfectStorage work in my virtual environment? for more information.

Operating Systems

Windows 8, Windows 7, Windows Vista, Windows XP


Windows Server 2012/2008/2003

Memory

64MB

Disk Space

64MB

Administrator privileges required in order to run 

Screen Shots

 

PerfectStorage Analysis of Recoverable SpaceClick to EnlargePerfectStorage SchedulePerfectStorage StealthPatrolClick to EnlargePerfectStorage Console

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PerfectStorage User Guides

PerfectStorage Client User Guide

PerfectStorage Enterprise Console User Guide

end faq

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Will PerfectStorage work with my storage controller?

PerfectStorage provides 2 different methods to help reclaim thin provisioned storage space: SCSI UNMAP and Zero Fill. 

The table below lists some common storage solutions and the methods supported to reclaim space. If your storage controller is not found in the list below, please contact Raxco Support for assistance. 

Manufacturer Controller Model SCSI UNMAP Support Zero Fill Support Notes
Dell EqualLogic   Y N SCSI UNMAP support added via DELL EqualLogic Array Software v6.0 and Host Integration Tools for Microsoft 4.5.
Dell Compellent   Y Y SCSI UMMAP support found in Compellent Storage Center V5.4 and newer.
EMC VNXe   N N The VNXe series of controllers does not support reclaiming space.
EMC VNX   Y Y SCSI UNMAP support added via EMC software update in late 2011.
HP
3PAR   Y Y SCSI UNMAP support added in

HP 3PAR OS 3.1.1.

Hitachi
    N Y Zero Fill support added in microcode level 60-04-04 or higher.
EMC Symmetrix VMAX N Y The Enginuity 5874 Q4 2009 service release introduced zero space reclamation that allows reclaiming data extents containing zero blocks.
Nimble     Y N With the Nimble Storage 2.0 Architecture release, Nimble added support for the VAAI UNMAP primitive - which means that on a Storage vMotion or vm deletion, space can be reclaimed from thin provisioned storage.
NetApp     N Y Space Reclaimer is a SnapDrive for Windows feature that optimizes LUN space by marking newly freed space that is visible to NTFS so that it is also seen as available by Data ONTAP. Data ONTAP 7.2.7 or later installed on your storage system. SnapDrive for Windows 5.0 or higher.
IBM XIV   Y Y

With the release of IBM XIV Storage System Gen3 11.2.x microcode, customers can begin to capitalize on the highly awaited space reclamation benefits associated with Small Computer System Interface (SCSI) UNMAP support. IBM XIV Gen3 FC and iSCSI volumes. 

Note: The smallest atomic unit that can be reclaimed via SCSI UNMAP is 1MB which corresponds to the fundamental building block size of an XIV volume known as a partition. 

Note: Although XIV volume used capacity reflects space reclamation upon host deletions, actual pool capacity is reclaimed in 17 GB units, also known as slices. XIV pool space reclamation occurs once an entire 17 GB slice is freed. This is due to the XIV grid architecture which always defines logical volume physical capacity in multiples of 17 GB (decimal) since each volume spans all physical drives in the system. IBM XIV Gen3 mirror volumes 

Note: SCSI UNMAP is supported for volumes that use synchronous mirroring as long as all XIV Storage Systems are using 11.2 code. SCSI UNMAP is not supported for volumes that use asynchronous mirroring.

HP LeftHand   N N

The LeftHand series of controllers running SAN I/Q v10 does not support reclaiming space.

NexentaStor     Y N 3.1 and higher required for SCSI UNMAP support

 

Will PerfectStorage work with my virtual environment?

PerfectStorage provides 2 different methods to help reclaim thin provisioned virtual drive storage space:  SCSI UNMAP and Zero Fill. 

The table below lists some common virtual environments and the methods supported to reclaim space in thin provisioned virtual guest drives.   If your virtual environment is not found in the list below, please contact Raxco Support for assistance. 

For pass-thru drives in virtual guests that connect to a thin provisioned LUN, perform the appropriate reclaim pass for the method that the storage controller supports to reclaim thin provisioned space.  For more information on storage controllers and reclaim methods supported, please see Will PerfectStorage work with my storage controller. 

 

Hyper-Visor Version SCSI UNMAP Support Zero Fill Support Notes
ESXi 5.0 Update 1 Y Y

To shrink thin provisioned guest drives, first run a Smart Zero Fill pass in the Windows Guest.  Afterwards, perform a Storage vMotion to move the guest vmdk(s) to a different data store that has a different block size 

If you do not have a different data store that is configured with a different block size, please do the following: 

- Shut down the virtual machine or temporarily remove the virtual disk from the virtual machine to ensure it is not in use. 

- Erase all unused blocks by running the command:

vmkfstools -K /path/to/disk-name.vmdk
 

Please see Storage vMotion to thin disk does not reclaim null blocks for additional information on data store block size limitations and Storage vMotion. 

Then run vmkfstools -y on the data store to issue SCSI UNMAP commands to reclaim space from the thin provisioned LUN.   

For more information on using vmkfstools, please see Using vmkfstools to reclaim VMFS deleted blocks on thin-provisioned LUNs (2014849)

ESXi 5.1 Y N

To shrink either a space efficient sparse virtual disk (SE sparse disk) OR a traditional thin-provisioned drive, run a SCSI UNMAP pass in the Windows Guest.  This is what is know as the "wipe" phase.  VMkernel intercepts these SCSI UNMAPs and shuffles the blocks to move these to the end of the virtual disk image.  VMkernel then performs the necessary operations to shrink the thin provisioned virtual drive.  Then run vmkfstools -y on the data store to issue SCSI UNMAP commands to reclaim space from the thin provisioned LUN.  

For more information on using vmkfstools, please see Using vmkfstools to reclaim VMFS deleted blocks on thin-provisioned LUNs (2014849) 

Virtual Machines require HWv9 in order for SCSI UNMAP commands issued in the guest to be detected and processed by VMkernel.

Hyper-V 2012 Y N

To shrink thin provisioned guest drives, run a SCSI UNMAP pass in the guest.  On shutdown or restart of the virtual guest, Hyper-V will shrink the size of the vhdx file. 

Note that since this requires the vm to be taken offline in order to shink the vhdx, storage administrators should synchronize host VHDX space reclamation with other guest OS maintenance windows that require guest downtime.  Via PerfectStorage post-reclaim tasks, the guest can be shut-down or restarted after a scheduled reclaim pass is performed. 

Hyper-V 2008/2008R2 N Y

To shrink thin provisioned guest drives, run a Smart Zero Fill pass in the guest.  Afterwards, using Hyper-V, edit the guest's dynamically expanding drive and select Compact. 

Note that since this requires the vm to be taken offline in order to compact the vhd, storage administrators should synchronize the compaction with other guest OS maintenance windows that require guest downtime. 

 ESXi

 4.x

 N

 Y

To shrink thin provisioned guest drives, first run a Smart Zero Fill pass in the Windows Guest.  Afterwards, perform a Storage vMotion to move the guest vmdk(s) to a different data store that has a different block size. 

If you do not have a different data store that is configured with a different block size, please do the following: 

- Shut down the virtual machine or temporarily remove the virtual disk from the virtual machine to ensure it is not in use. 

- Erase all unused blocks by running the command:

vmkfstools -K /path/to/disk-name.vmdk
 

Please see Storage vMotion to thin disk does not reclaim null blocks for additional information on data store block size limitations and Storage vMotion. 

 

end faq

 

 

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Intelligent Space Reclamation in Thin-Provisioned Environments

The benefits provided by thin provisioning and over-allocation of storage allow businesses to optimize storage allocation at potentially reduced costs, while preserving performance.

At the same time, thin provisioning can result in misallocation of storage, which results in wasted space, excess capacity and unnecessary expenditures if not managed properly.

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