Release Notes

Release Notes— Fluid Cache for SAN for VMware Systems
WORKAROUND: No action is required. The backing LUN will only appear temporarily and will
be cleaned up within 24 hours.
Guest VM I/O Timed Out or Experienced Very Long Delays
ISSUE: Under some circumstances when the cache contains a large amount of dirty cache
blocks, power cycling a node or removing a cache device in the cluster may cause I/O to hang in
one or more of the guest VMs in the cluster.
WORKAROUND: Set the cache mode to Write-Through to avoid filling the cache with dirty
blocks.
Guest VMs Becomes Unresponsive and/or ESXi host cannot be
managed by vSphere
ISSUE: Under some circumstances if the back end storage experiences performance issues, the
TGT stack on the ESXi hosts can timeout causing guest VMs to become unresponsive and/or
ESXi host to become unmanageable.
WORKAROUND: To recover from this situation reboot the ESXi host that is experiencing the
issue. To help avoid future issues:
1. Review state of back end storage to identify performance issue and resolve.
2. Manually change the Queue Depth settings inside ESX using the following steps:
a. Use the vSphere Client or vSphere Web Client to navigate to the Configuration tab of
the VMware ESX host you want to modify.
b. Click Advanced Settings under the Software section.
c. Click Disk in the left side pane.
d. Set QFullSampleSize to a value greater than zero. The usable range is 0 to 64.
i. Set the QFullSampleSize value to 32.
e. Set QFullThreshold to a value lesser than or equal to QFullSampleSize. The usable
range is 1 to 16.
i. Set the QFullThreshold value to 8.
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Page 12 3/9/2015