After playing around for a while, I was able to get the Distribution of Volume Across Members back to the R50 array after I:
1) Decreased the number of total snapshots saved -- From four to three snapshots
2) Deleted all of the existing snapshots and created a new snapshot backup
3) Decreased the Snapshot Reserve percentage
After doing all of those things, the storage pool pie chart says: Reserved for Volumes 4.85 TB (54.6%); Reserved for Snapshots 1.58 TB (17.7%); Free Space 2.46 TB (27.6%).
The free space on each array is now: R10 2.04 TB; R50 2.12 TB.
So now, it's been resolved.
Is it safe to say that in this case, the volume was "over-subscribed" due to the snapshots using too much space?
Based on your description, it seems that the volume is not properly honoring the RAID preference. We will need you to open a support case so that we can look at both arrays to see what is going on. Prior to opening the case, please run the diags from both members.
Regarding additional information about load balancing, go to: support.equallogic.com/.../tech_reports.aspx (support user account login required) and you should see the document titled: Using Tiered Storage in a PS Series SAN.
The behavior you described would be normal and what would be expected. Snapshots share the same volume pages as the base volume, so they would live on the same member as the base volume. By deleting snapshots, you freed up enough space for the base volume pages to move to the correct member for your RAID preference.
dajonx
2 Intern
•
294 Posts
1
September 22nd, 2011 12:00
Joe,
Thank you for your response.
After playing around for a while, I was able to get the Distribution of Volume Across Members back to the R50 array after I:
1) Decreased the number of total snapshots saved -- From four to three snapshots
2) Deleted all of the existing snapshots and created a new snapshot backup
3) Decreased the Snapshot Reserve percentage
After doing all of those things, the storage pool pie chart says: Reserved for Volumes 4.85 TB (54.6%); Reserved for Snapshots 1.58 TB (17.7%); Free Space 2.46 TB (27.6%).
The free space on each array is now: R10 2.04 TB; R50 2.12 TB.
So now, it's been resolved.
Is it safe to say that in this case, the volume was "over-subscribed" due to the snapshots using too much space?
Joe S586
7 Technologist
•
729 Posts
0
September 22nd, 2011 11:00
dajonx,
Based on your description, it seems that the volume is not properly honoring the RAID preference. We will need you to open a support case so that we can look at both arrays to see what is going on. Prior to opening the case, please run the diags from both members.
Regarding additional information about load balancing, go to: support.equallogic.com/.../tech_reports.aspx (support user account login required) and you should see the document titled: Using Tiered Storage in a PS Series SAN.
Regards,
Joe
Joe S586
7 Technologist
•
729 Posts
0
September 22nd, 2011 13:00
dajonx,
The behavior you described would be normal and what would be expected. Snapshots share the same volume pages as the base volume, so they would live on the same member as the base volume. By deleting snapshots, you freed up enough space for the base volume pages to move to the correct member for your RAID preference.
So, you don’t need to open a support case.
Regards,
Joe