ZFS & Bittorent -> Hang?

[Claus Guttesen]

>  OK.  I've been able to reproduce the issue.
>
>  Conditions:
>  - Stock shipped kernel and modules from RELENG 7.0
>
>  loader.conf settings:
>  - zfs prefetch enabled
>  - zfs zil disabled
>  - vm.kmem_size_max="1073741824"
>  - vm.kmem_size="1073741824"
>
>  AMD64 on Core 2 Duo w/ 4 GB RAM
>
>  raidz across 4 disks, using root on zfs (also experienced this hang with zfs
>  just on /usr)
>
>  How To Reproduce
>  - install transmission-daemon, run transmission-daemon (it will daemonize,
>  automatically backgrounding)
>  - grab a torrent, such as KNOPPIX (http://torrent.unix-ag.uni-kl.de/)
>  - transmission-remote -a <torrentfile> (add the torrent)
>  - transmission-remote -s all  (start all the torrents)
>
>  wait hours to a day or so with whatever you want logging things running and
>  active since anything that hits disk after the hang will get hung as well
>
>  I've just done this twice.  It doesn't seem to happen with zil enabled and
>  prefetch off.
>
>  Expected Behavior
>  No hang.

Thank you for spending time on this. I'm getting some jbod-storage in
a few weeks and will spend some time using various block-sizes and
share partitions across nfs. I'm somewhat confident that zfs on
FreeBSD will work fine but Solaris is (of course) also an option. This
will be approx. 7 TB to begin with and growing upwards to some two
digit TB's.

What is the largest storage zfs on FreeBSD has been used on? I tried
it for some month on 8 TB.

-- 
regards
Claus

When lenity and cruelty play for a kingdom,
the gentlest gamester is the soonest winner.

Shakespeare