We were using a portable storage array as temporary storage array to store data from an older array that had to be reconfigured. Capacity was quite an issue and everything would barely fit (with dedupe and compression doing its best on the Dell EMC XtremIO we were using for this), but we discovered that provisioned space wasn’t immediately reclaimed, so we got a bit into trouble when space wasn’t immediately reclaimed when data was deleted from a VMware version 5 datastore.

We were facing two options:

• Datastore VMFS version 6: Unmap automatically every 12 hours (not 100% sure about this interval)
• Datastore VMFS version 5: Unmap manually from the ESXi command line:

esxcli storage vmfs unmap -l XIO-05-VMFS-013

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