Anyone using freebsd ZFS for large storage servers?

Dan Nelson dnelson at
Fri Jun 1 15:35:32 UTC 2012

In the last episode (Jun 01), Wojciech Puchar said:
> > and unbelievable narrow cases, when you don't have or can't access a
> > backup (which you should have even when using ZFS), and you _need_ to do
> > some forensic analysis on disks, ZFS seems to be a worse solution than
> > UFS.  On ZFS, you never can predict where the data will go.  Add several
> > disks to
> true. in UFS for example inodes are at known place, and flat structure
> instead of "tree" is used.
> even if some sectors are overwritten with garbage then fsck can scan over
> inodes and recover all that can be recovered.
> ZFS is somehow in that part similar to Amiga "Fast" File System. when you
> overwrite a directory block (by hardware fault for example), everything
> below that directory will disappear.  You may not be even aware of it
> until you need that data

On the other hand, even on a single-disk pool, ZFS stores two copies of all
metadata, so the chances of actually losing a directory block are extremely
remote.  On mirrored or RAIDZ pools, you have at least four copies of all

	Dan Nelson
	dnelson at

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