On Tue, May 29, 2012 at 2:30 PM, Kees Jan Koster <kjkos...@gmail.com> wrote: > Dear Freddie, > >> Granted, I haven't played with gsched yet (most of our high-I/O >> systems are ZFS), so there may be a way to use it across-GEOMs. > > From my previous experiments ZFS suffers the same fate when there is heavy > write activity. Reads just don't get served in time. > > How do you deal with that?
We're currently only using FreeBSD (and ZFS) on our backups servers. The two main servers do rsync backups for ~150 remote Linux servers and FreeBSD firewalls (1 server does the elementary and secondary schools; the other server does the admin sites). Then they do zfs sends to a third system off-site. Thus, our workloads tend to be fairly one-sided (all reads on the zfs send side; all writes on the zfs recv side; mostly reads on the rsync side side with some writes). And, most of our working set fits into ARC/L2ARC. Cache devices really help, as most reads come from the L2ARC, while most writes go straight through to the pool. We're still a year or so away from our ultimate goal of using FreeBSD+ZFS+NFS to create a separate/proper SAN/NAS tier for our virtual servers. At that point, we'll look a little deeper into things, and experiment with different L2ARC/ZIL setups to optimise read and write paths. -- Freddie Cash fjwc...@gmail.com _______________________________________________ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "freebsd-stable-unsubscr...@freebsd.org"
