Snapshot Help Needed - out of space no snapshots were created

[swezey]

So we have our TrueNas up and running for about 3 months now and it's doing great EXCEPT... I can not make a snapshot. Always I get this error:

Snapshot Task For Dataset "VIPER_AFA/viperiscsiafa" failed: cannot create snapshot 'VIPER_AFA/viperiscsiafa@auto-2022-08-24_00-00': out of space no snapshots were created..​

2022-08-24 00:00:00 (America/New_York)

There is a single pool and it reports as follows:

ONLINE check_circle | 28.06 TiB (79%) Used | 7.45 TiB Free

This is an iSCSI share. However, on the Windows file server it reports:

15.9TB free of 27.9TB

Certainly, I should have enough space to take a snapshot.? Does anyone have an idea what gives? Maybe I am not understanding this data correctly. TrueNAS newbie here so I am sure it is something dumb but I can't figure out why it keeps saying I don't have enough room for a single snapshot. Thanks for your help!

Bill

 

[Heracles]

You may have quotas for the dataset and its children and it is that quota that is exceeded / reached. Good for you because a full pool will get destroyed instantly and you will loose everything. Never let a pool grows that big. 80% of use is extremely high and you must add space in that pool ASAP.

As for the free space reported by Windows, this is of no use for TrueNAS. TrueNAS reserved the full zvol allocated to Windows and itself has no clue what is used or not within it. The reason is that the filesystem is managed by Windows and not TrueNAS / ZFS.

 

[swezey]

Heracles thanks for that info. So yes you are right, when I went to make the pool it would not allow me to use the entire combined drive size and suggested (or forced - I forget) that 80% or less be used. (What happens to the 7.45TB of flash that is unused - can it never be used?) So that's why the pool is basically 80%. The pool is nowhere near full of data but I guess since it is committed it is considering it used.

How can I check if there are quotas? How do I increase the size of the pool? If I add more space to it from the 7TB that is sitting there unused how does this help when it wouldn't let me use it initially in the first place? This is all very confusing to me. Is there a primer on this somewhere that I can read that is in laymen's terms? I am not a computer guy - just a guy at a small company that is trying to keep this operation going.

Oh and a file system that loses data when the pool gets full doesn't sound very robust to me. Surely there are fail safes in place for this?

Any direction you can provide is greatly appreciated. I really would like to use snapshots as part of our backup / DR strategy. Thanks!

Bill