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Citrix XenServer: Errors with PHD VBAs using multiple vCPUs - Connect IT Community | Kaseya
<main> <article class="userContent"> <h2 data-id="summary"><strong>SUMMARY</strong></h2> <p>An example warning message is: WARNING - Unplug of OpaqueRef:62293bfe-c76e-71d4-533d-090699d39fcf failed</p> <h2 data-id="issue"><strong>ISSUE</strong></h2> <p></p> <p>PHD VBAs configured with multiple vCPUs on Citrix XenServer v6.0 may encounter intermittent warnings when attempting to automatically remove snapshots. An example warning message is:</p> <blockquote class="blockquote"> <p>WARNING - Unplug of OpaqueRef:62293bfe-c76e-71d4-533d-090699d39fcf failed: INTERNAL_ERROR</p> </blockquote> <p>This issue appears to be related to a failure in Citrix API call (hot unplug process). PHD has been in contact with the Citrix development team to attempt to discover the root cause of this issue. A timetable for a fix is not currently available.</p> <p>A workaround for this issue is to first reconfigure the PHD VBA to use a single vCPU. Depending on your specific hardware and environment, 1 vCPU will provide full throughput of up to 8 streams.</p> <p>To find the optimal number of streams, run your backup job multiple times, incrementing the number of streams by 1 each run. Once the vCPU has saturated, you will see an increase in job elapsed time and a degradation of I/O throughput as reported in the Job Details.</p> <p> </p> <p>In addition to snapshots being automatically removed, the leaf coalesce procedure for XenServer will help with any cleanup process by regaining free space.</p> <p> </p> <p><strong>Note that prior to XenServer 6.0, multiple vCPUs were not supported for Debian-based VM guests.</strong></p> </article> </main>