Where did all my storage go?

[dpearcefl]

Ignoring the small "jails" dataset for the moment, am I correct in saying the difference between the size of my dataset "Storage" (28.8 TB) and the volume "Storage" (40.5 TB) is the amount of space taken by snapshots? Or is something else using that space (11.7 TB)?

Thanks.

 

[Vito Reiter]

The very top 'Storage' is FULL disk capacity, so if you have 10x4 or 5TB Disks, you'd see 40-50TB there, the Dataset under it has an amount based on the redundancy, so ACTUAL available space opposed to the top 'Storage', your volume, showing raw used space on your drive. Basically, your true 'Used' and 'Available' storage will be on the dataset, not the volume, because the dataset shows what you can use based on the type of redundancy set up.

 

[dpearcefl]

OK, answering my question myself (again). "Storage" is a RAIDZ2 pool (8 times 6 TB drives). While I still don't understand all of the numbers, RAIDZ2 means I lose two drives of storage and those two drives figure into the calculations of the smaller number.

 

[dpearcefl]

And Bad on me for mixing TiB and TB. 40 lashes with a wet noodle!

 

[Vito Reiter]

Yes, so the top 'Storage' volume will show the value of 8x6TB drives while the 'Storage' dataset under it will show 8x6TB minus ABOUT 2x6TB for redundancy. Also, yes FreeNAS is in TiB not TB, confuses a lot of people, even though the difference is small it grows exponentially when dealing with larger pools.

 

[Vito Reiter]

Also, HERE is a calculator made by a forum member, really good tool.

 

[dpearcefl]

And just to beat a dead bantha, Deleting files will NOT release disk space if the deleted file is part of a snapshot.

 

[Vito Reiter]

And just to beat a dead bantha, Deleting files will NOT release disk space if the deleted file is part of a snapshot.

Not until that snapshot is deleted or replaced

 

[nojohnny101]

I think you have it correct @dpearcefl

If you have snapshots of a dataset, and you delete a file in that dataset, that space will not be released until all the snapshots that contain a reference to that file are also purged.

 

[Stux]

I think you have it correct @dpearcefl

If you have snapshots of a dataset, and you delete a file in that dataset, that space will not be released until all the snapshots that contain a reference to that file are also purged.

And technically, the references are to blocks and not files ;)