ZFS requires specific tuning for use as a cache partition; otherwise, its allocation size interacts poorly with the allocation size of cache chunks, IIRC. I'd imagine something similar is true of btrfs, but I know even less about btrfs implementation details than ZFS.
-----Original Message----- From: openafs-info-ad...@openafs.org [mailto:openafs-info-ad...@openafs.org] On Behalf Of Benjamin Kaduk Sent: Wednesday, May 4, 2016 10:21 PM To: Fred Drueck <fdru...@uic.edu> Cc: openafs-info@openafs.org Subject: Re: [OpenAFS] /var/cache/openafs on btrfs On Wed, 2 Mar 2016, Fred Drueck wrote: > Hello Everyone, > > According to the OpenAFS admin FAQ, it appears that the officially > supported file systems for the disk cache are: > > ext2 > ext3 > hfs (HP-UX) > xfs (at least on IRIX 6.5) > ufs (Solaris, ?Tru64Unix) > > which is clearly out of date, since there is a working implementation > for OS X that runs on top of HFS+ > > For some time I've been fearlessly using both ext4 and btrfs (on > Linux, as you might infer) as the backing storage for my AFS client cache. > > I have noticed some fairly rare issues with the clients if all file/db > servers (in our cell the same machines) become unavailable. The '/afs' > mount becomes un-accessible and attempts to access files often result > in very long timeouts. I've always been able to fix things by somehow long timeouts are expected when all the db servers are inaccessible. > shutting down the client (in the worst case by physical power-off and > reboot into single user mode) and deleting the cache. > > Is there some chance that this is because I've been causing these > problems by using un-supported file-systems as the backing storage for > the client cache? I think there is some chance, but this is not an area I've looked into for quite some time, and may be misremembering. I do have some recollection that ZFS behaves poorly for a cache partition, and given btrfs's similarities to ZFS, would not really recommend it either, absent further research. -Ben _______________________________________________ OpenAFS-info mailing list OpenAFS-info@openafs.org https://lists.openafs.org/mailman/listinfo/openafs-info :�� T���&j)b� b�өzpJ)ߢ�^��좸!��l��b��(���~�+����Y���b�ا~�����~ȧ~
