On 4/6/2011 1:16 PM, Lamar Owen wrote:
There are other issues with XFS and 32-bit; see: http://bugs.centos.org/view.php?id=3364 and http://www.mail-archive.com/scientific-linux-users@listserv.fnal.gov/msg0534... and google for 'XFS 32-bit 4K stacks' for more of the gory details.
Thanks for the info.
The problem seems to be tied to LVM and high amounts of I/O, particularly writes. None of that applies to this application. The filesystem is a plain-old partition, the array is mostly going to be read-only, and due to a bottleneck elsewhere in the system, the peak read rate can't be higher than 20 Mbyte/s.
(If you're wondering, then, why I bothered to benchmark the system at all, it's because we get much higher I/O rates when initially loading the array up, so that the low write speed of ZFS-FUSE would have increased that initial load from days to weeks.)
That load went off without a hitch, so we've probably already done the worst thing to this server that it will ever see. (Kind of like the old advice for happiness: eat a bug every morning, and nothing worse will happen to you for the rest of the day.)
We'll test it under load before shipping it anyway, however.