[OpenAFS] Re: [ Openafs : cache on zfs ]

Andrew Deason adeason@sinenomine.net
Thu, 3 Oct 2013 13:16:58 -0500

On Thu, 3 Oct 2013 19:34:27 +0200
nicolas prochazka <prochazka.nicolas@gmail.com> wrote:

> Hello again ,
> after some tests to use zfs as afs cache,
> linux kernel tells :
> BUG : soft lockup - CPU0 stuck for 23s ! [ afs_cachetrim:2908]
> Any ideas are welcome,

It seems pretty likely from your other message that using zfsonlinux for
the openafs client cache is not going to work at all until someone takes
the time to add support for it. Just use another filesystem.

Even on other platforms, ZFS has some characteristics that make it not
ideal for a cache, and in the past I've recommended using something else
when it's easy to do so (e.g. UFS on Solaris, even if it's jus on a
zvol). At least on Solaris, ZFS does some somewhat unique things with
space allocations that have created some semi-unavoidable problems for
the cache manager.

I can understand if someone is using ZFS for their root fs, and they
don't want to make a separate fs just for the cache, but if you're
making an fs just for the cache or something, it doesn't make a lot of

Andrew Deason