Dell EMC Unity: How to enable and disable compression on an existing storage resource (User Correctable)
Summary: Dell EMC Unity Compression can be enabled or disabled on supported storage resources at any point in time. This can easily be accomplished using either Unisphere, Unisphere CLI, or REST API. The following sections outline how you can easily enable and disable compression on existing storage resources using Unisphere and Unisphere CLI. ...
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Instructions
LUNS
To enable and disable compression on an existing LUN, review the properties of the LUN from the Block page. The Block page can be accessed by selecting Block under Storage in the left Unisphere pane. After double clicking the Name of the LUN, or after selecting a LUN and clicking the Pencil (View/Edit) icon, the LUN Properties window is displayed. On the General tab, a checkbox for Compression exists. Depending if compression is currently disabled or enabled on the storage resource, the box will either be unchecked or checked. To change the state of compression, simply check or uncheck the Compression box and click Apply.
Figure 10 below shows the Properties window of a LUN which currently has Compression disabled. The Compression box has been selected to enable compression on the resource, but Apply has not yet been selected. When enabling compression on a resource, an informational message is displayed after checking the Compression box.
The message states: Only the newly written data will be compressed. Existing data will remain uncompressed. You may click "Compress Now" from More Actions on the LUN table to compress the newly written data and existing data.
This message outlines that the Compress Now option must be used to compress the existing data within the storage resource if desired. If the Compress Now option is not utilized, then only new writes to the LUN or overwrites to existing data within the LUN are considered for compression.
To enable and disable compression on an existing LUN, review the properties of the LUN from the Block page. The Block page can be accessed by selecting Block under Storage in the left Unisphere pane. After double clicking the Name of the LUN, or after selecting a LUN and clicking the Pencil (View/Edit) icon, the LUN Properties window is displayed. On the General tab, a checkbox for Compression exists. Depending if compression is currently disabled or enabled on the storage resource, the box will either be unchecked or checked. To change the state of compression, simply check or uncheck the Compression box and click Apply.
Figure 10 below shows the Properties window of a LUN which currently has Compression disabled. The Compression box has been selected to enable compression on the resource, but Apply has not yet been selected. When enabling compression on a resource, an informational message is displayed after checking the Compression box.
The message states: Only the newly written data will be compressed. Existing data will remain uncompressed. You may click "Compress Now" from More Actions on the LUN table to compress the newly written data and existing data.
This message outlines that the Compress Now option must be used to compress the existing data within the storage resource if desired. If the Compress Now option is not utilized, then only new writes to the LUN or overwrites to existing data within the LUN are considered for compression.
Figure 11 below shows the Properties window of a LUN which currently has Compression enabled. The Compression box has been deselected to disable compression on the resource, but Apply has not yet been selected. When disabling compression on a resource, an informational message is displayed after unchecking the Compression box. The message states:
Existing data will remain compressed. Newly written data will not be compressed.
This message implies that the Move option must be used to uncompress the existing data within the storage resource if desired. If the Move option is not utilized, then only overwrites to the LUN will cause compression savings to decrease.
Existing data will remain compressed. Newly written data will not be compressed.
This message implies that the Move option must be used to uncompress the existing data within the storage resource if desired. If the Move option is not utilized, then only overwrites to the LUN will cause compression savings to decrease.
Unisphere CLI can also be used to enable and disable compression on an existing LUN. In Unity OE codes which support compression, a new compression option has been added to the /stor/prov/luns/lun set command. Below is the usage of the /stor/prov/luns/lun set command.
uemcli -d x.x.x.x -u username -p password /stor/prov/luns/lun -help
LUN Actions:
Set] /stor/prov/luns/lun -id set [ -async ] [ -name ] [ -descr ] [ -size ] [ { -group | -standalone } ] [ { -sched | -noSched } ] [ -schedPaused { yes | no } ] [ -spOwner { spa | spb } ] [ -fastvpPolicy { startHighThenAuto | auto | highest | lowest } ] [ -lunHosts ] [ -snapHosts ] [ -replDest { yes | no } ] [ -compression { yes | no } ] [ { -ioLimit | -noIoLimit } ]
Below is an example of enabling compression on an existing LUN named AF LUN 1, which has a CLI ID of sv_1, using Unisphere CLI. Disabling compression is just as easy, and can be accomplished by simply swapping compression yes for compression no.
uemcli -d x.x.x.x -u username -p password /stor/prov/luns/lun lun -id sv_1 set -compression yes
ID = sv_1
Operation completed successfully.
uemcli -d x.x.x.x -u username -p password /stor/prov/luns/lun -help
LUN Actions:
Set] /stor/prov/luns/lun -id set [ -async ] [ -name ] [ -descr ] [ -size ] [ { -group | -standalone } ] [ { -sched | -noSched } ] [ -schedPaused { yes | no } ] [ -spOwner { spa | spb } ] [ -fastvpPolicy { startHighThenAuto | auto | highest | lowest } ] [ -lunHosts ] [ -snapHosts ] [ -replDest { yes | no } ] [ -compression { yes | no } ] [ { -ioLimit | -noIoLimit } ]
Below is an example of enabling compression on an existing LUN named AF LUN 1, which has a CLI ID of sv_1, using Unisphere CLI. Disabling compression is just as easy, and can be accomplished by simply swapping compression yes for compression no.
uemcli -d x.x.x.x -u username -p password /stor/prov/luns/lun lun -id sv_1 set -compression yes
ID = sv_1
Operation completed successfully.
Additional Information
For more information on using the Compression feature and Best Practices, please see the following KB articles
https://support.emc.com/kb/494004 - Using the Unity "Compress now" option could result in high response times
https://support.emc.com/kb/493765 - Unity: How to use Compression - considerations and best practices.
https://support.emc.com/kb/494004 - Using the Unity "Compress now" option could result in high response times
https://support.emc.com/kb/493765 - Unity: How to use Compression - considerations and best practices.
Affected Products
Dell EMC Unity FamilyProducts
Dell EMC Unity Family |Dell EMC Unity All Flash, Dell EMC Unity FamilyArticle Properties
Article Number: 000022789
Article Type: How To
Last Modified: 23 Nov 2020
Version: 2
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