vSAN - Deduplication is not showing any space savings
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Article ID: 326561
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Updated On:
Products
VMware vSAN
Issue/Introduction
Symptoms:
vSAN cluster with deduplication and compression enabled is seeing no result in the deduplication and compression overview.
Summary tab screen reports that no space is being saved by deduplication and compression.
You see low deduplication ratio.
Cause
This issue occurs because objects are 100% reserved.
Resolution
Run this command on any of the hosts as it will display all disk information in the cluster:
esxcli vsan debug disk list.
The output from the command above is reporting all disks with high amount of reserved space.
To fix this issue, ensure the storage policies are not set for object space reservation: 100% (Thick provisiong):
Click Menu > Policies and Profiles > Click VM Storage Policies > search for the vSAN Storage Policy or the custom policy used and select it, this will display the policy details and show it has 100% reservation:
Workaround:
You can run this command on RVC to show disks stats as well and see object space reservation: