Operational Defect Database
BugZero found this defect 3239 days ago.
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Veeam | kb2052
Slow Restore Performance With Direct SAN Mode
Last update date:
11/11/2022
Affected products:
Veeam Backup & Replication
Affected releases:
ALL
Fixed releases:
No fixed releases provided.
Description:
Challenge
When performing a Full VM Restore or Virtual Disk Restore using Direct SAN Restore, the performance may be sub-optimal when the restored Disk Type Setting is set to Thick (lazy zeroed).
Cause
When using Direct SAN to restore a disk with it's disk type set to Thick (lazy zeroed), overall restore performance can be affected because of repeated disk manager API calls to ClearLazyZero and AllocateBlock.
Solution
Option 1: Use 'Thick (eager zeroed)' Disk Type When restoring via Direct SAN, disks must be restored as Thick, either lazy zeroed or eager zeroed. Performance has been shown to be much higher when using the eager zeroed option1. Entire VM Restore On the Datastore tab of the Full VM Restore wizard, use the Disk Type button in the bottom-right corner to set the restored disk type to "Thick (eager zeroed)."
