ZFS vs. df -h completely different size of filesystem [solved]
josh at multipart-mixed.com
Sun Oct 11 18:18:44 UTC 2009
> But space remains occupied by data of snapshots! Thats why df showed
> just 24G size and not 360G. Df knows nothing about snapshots.
Some additional factors to keep in mind when looking at ZFS and used/
available disk space:
- Snapshots (as you discovered).
- Compression: when compression is turned on (as you have), you can't
know exactly how much more data will fit into the filesystem because
it depends on how well the data compresses.
- Sparse files: "ls -h" will show you how large a file says it is; "du
-h" and "zfs list" should show how much space is actually used. These
will disagree on sparse files.
- Space reserved for copy-on-write: "zpool list" and "zfs list" will
differ on available space because ZFS reserves some amount of slop
space; truly running out of blocks is disastrous in a COW system.
In general, learn to trust "zfs list" because the traditional tools
don't know the full story.
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