Can you list internal checksums of a ZFS filesystem?

[Steven Hartland]

----- Original Message ----- 
From: "CH" <freebsd-fs at ch.pkts.ca>

> Actually, I did do rsync for the initial transfers, and it had to be
> restarted a couple of times for reasons that were not its fault (source
> computer rebooted, ssh connection lost, etc).  However, after it
> finished copying everything (ie: exiting normally), I ran it again, and
> it found more stuff to copy.  This shouldn't have happened since
> nothing was added to the source computer, and so now I distrust its
> results and want to check it independently.  In particular, I don't
> trust its directory-walking algorithm, so some files may have been
> missed and may continue to be missed in future runs of rsync, with or
> without -c.
> 
> The method I was going to use was 'find . -type f -print0 | xargs -0
> md5sum > my.big.md5sum.file' on both source and destination, but if I
> can harvest the ZFS checksums (file or block) it would cut the cpu
> workload in half, and save a tree's worth of energy.

rsync is reliable when run on run cleanly. If like you had interruptions
and you where running using say -av then it can miss changes if files
changed but size or timestamps didn't.

I've never had an run complete cleanly with a re-run detecting new
files where files weren't in fact added.

As mentioned --checksum (-c) forces checksums to be compared on both
ends which will allow you to verify all is good.

    Regards
    Steve

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