DELL 34XX User Manual
For a consistency group snapshot virtual disk:
set cgSnapVirtualDisk ["cgSnapshotVirtualDisk"]
set cgSnapVirtualDisk ["cgSnapshotVirtualDisk"]
ssdCacheEnabled=TRUE
When you turn off SSD caching for a virtual disk, cache contents is purged. You can turn on SSD caching
for only one virtual disk per command.
for only one virtual disk per command.
Creating SSD Cache
To create ssdCache command SSD read cache:
create ssdCache userLabel="ssdCacheName"
create ssdCache userLabel="ssdCacheName"
physicalDisks=(enclosureID1,drawerID1,slotID1 ...
enclosureIDn,drawerIDn,slotIDn)
[updateExistingVirtualDisks=(TRUE|FALSE)]
The ssdCacheName parameter names the cache group. Setting the updateExistingVirtualDisks
parameter to TRUE enables SSD caching for all virtual disks in the storage array.
parameter to TRUE enables SSD caching for all virtual disks in the storage array.
The following restrictions apply:
• A storage array can have only one SSD cache.
• Only virtual disks created using physical disks can use the SSD cache. You cannot enable SSD cache
• Only virtual disks created using physical disks can use the SSD cache. You cannot enable SSD cache
on snapshot (legacy) virtual disks or snapshot images.
• SSD caching does not support self-encrypting disks (SEDs).
Adding Physical Disks To Existing SSD Cache
To add to or increase the capacity of an existing SSD cache, use the set ssdCache command:
set ssdCache [ssdCacheName]
set ssdCache [ssdCacheName]
addPhysicalDisks=(enclosureID1,drawerID1,slotID1 ...
enclosureIDn,drawerIDn,slotIDn)
Removing Physical Disks From Existing SSD Cache
To remove physical disks from existing SSD Cache:
set ssdCache [ssdCacheName]
set ssdCache [ssdCacheName]
removePhysicalDisks=(enclosureID1,drawerID1,slotID1 ...
enclosureIDn,drawerIDn,slotIDn)
You cannot remove all physical disks from an SSD Cache, and at least one physical disk must remain. To
completely remove the SSD Cache, use the delete ssdCache [ssdCacheName] command.
completely remove the SSD Cache, use the delete ssdCache [ssdCacheName] command.
SSD Cache Performance Modeling
SSD Cache Performance Modeling helps you determine potential performance improvement based on
different SSD cache capacities. The modeling tool provides an estimate of performance using the
following criteria:
different SSD cache capacities. The modeling tool provides an estimate of performance using the
following criteria:
• cache hit percentage
• average response time
• average response time
To start the modeling tool from the command line:
start ssdCache [ssdCacheName]
start ssdCache [ssdCacheName]
performanceModeling
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