Snapshots usage

  • 26 January 2015
  • 1 reply
  • 1303 views

Badge +11
Hi,

I was hoping if someone can shed a light on some queries I have re snapshots. I am running low on space to the point where I currently have no autobuild resiliency. I do get a FAIL when it comes to snapshot_chain_length when checking with NCC.The value of that is 41 and ideally should be around 10. I have 3 protection domains with a total of 127 VM. I do a daily snapshot but only retain one copy. I have been getting too many snapshot alerts even when I only had snapped 50 VM in one protection domain.

-Can someone explain what that snapshot_chain_length actually is and where the 41 comes from?
-How much space is actually used by the snapshots? How can I get this info (NOS 4.0.1.2)
-Each protection domain has 4 expired snapshots in addition to my one active snapshot. Do these actually take up space? What is their purpose? If I am not mistaken they can not be used for restores.

This topic has been closed for comments

1 reply

Userlevel 4
Badge +18
1. snapshot_chain_height check check checks for any snapshot chain containing more than 25 snapshots, and reports a FAIL status if it detects more than 25.

2. You can check the space used column for each protection domain in Web UI for space used in snapshots.

3. As far as expired snapshots is concerned, they do take up space and for each protection domain, there is a default design of keeping 5 expired snapshots, so there will be 5 expired snapshots present until the 6th one shows up and delete operation deletes the oldest snapshot. This was done in case customer wants to use the old snapshots. This setting can be changed but for that I would suggest you to open up a ticket with Nutanix support before making these changes.