Search the VMware Knowledge Base (KB)
View by Article ID

vSAN 6.2 increase in used disk space with All-Flash and Deduplication (2147343)

  • 5 Ratings

Symptoms

You experience an increase in used disk space over time with environments that meet these requirements
  • The vSAN 6.2 (formerly known as Virtual SAN) and later cluster is using All Flash.
  • Deduplication and Compression is on.
  • The disk group size is greater than 1.6TB.
  • Greater than 16TB of deletes on a disk group. 

    Note: This 16TB includes resynchronization and other general maintenance tasks.

Purpose

This article provides information on a known issue with vSAN 6.2, with All-Flash and Deduplication enabled.

Cause

This issue is caused by an error in the deduplication algorithm, where after 16 TBs of deletes on a disk group is executed, the vSAN datastore will lose space on every subsequent delete operation causing used space to grow over time.

Environments that utilize heavy delete operations, such as a VDI workload with a policy of refresh/delete on logoff, may encounter this issue.

Resolution

This issue is resolved in ESXi 6.0, patch ESXi600-201611001. However, VMware recommends to upgrade your vSAN infrastructure to vSphere 6.0 Update 3, available at VMware Downloads.

Note: This issue does not affect vSAN 6.5.

This issue occurs under these conditions:
  • The vSAN cluster is using All Flash.
  • Deduplication and Compression is on.
  • The disk group size is greater than 1.6TB.
  • Greater than 16TB of deletes on a disk group.
If  you believe you are encountering this issue and cannot apply the patch, closely monitor your environment and file a support request with VMware Support referencing this article(2147343) .For more information on filing a support request, see How to file a Support Request in My VMware (2006985).

Additional Information

To be alerted when this article is updated, click Subscribe to Document in the Actions box.

See Also

Update History

11/22/2016 - ESXi 6.0-P04 addressed this issue. 03/21/2017 - Added recommendation to upgrade to 6.0 U3

Request a Product Feature

To request a new product feature or to provide feedback on a VMware product, please visit the Request a Product Feature page.

Feedback

  • 5 Ratings

Did this article help you?
This article resolved my issue.
This article did not resolve my issue.
This article helped but additional information was required to resolve my issue.

What can we do to improve this information? (4000 or fewer characters)




Please enter the Captcha code before clicking Submit.
  • 5 Ratings
Actions
KB: