zfs, nfs and zil
Alexander at Leidinger.net
Mon Mar 28 14:56:56 UTC 2011
Quoting Claus Guttesen <kometen at gmail.com> (from Mon, 28 Mar 2011
> I've setup a server with FreeBSD 8.2 (prerelase) and patched zfs to
> ver. 28. The server has 11 disks each 2 TB in raidz2. The performance
> is very good and I've got approx. 117 MB/s on plain GB nics using
> I'm mounting the FreeBSD-server from a couple of vmware esxi 4.1
> servers using nfs, but when there is alot of i/o the server becomes
> unresponsive, easily triggered by installing ie. ms-sql. The server
> itself is up but is not reachable from the network. When I take the
> nic down and up again connection to the network is reestablished
> A friend of mine has suggested that I disable the zil. The page
> http://wiki.freebsd.org/ZFSTuningGuide says 'Disabling ZIL is not
> recommended where data consistency is required (such as database
> servers) but will not result in file system corruption.'
> Has anyone tried to disable zil and achieved better performance and
> still maintain a consistent filesystem?
The ZIL is not linked to NIC down/up events. It is a completely
different topic. I suggest to find the real problem instead of doing
some random tuning (which is not tuning in this case but foot-shooting).
FYI: disabling the ZIL is someting to do if you are desperate, do not
care about production incidents, and everything else (if the ZIL is
the problem -- which most probably it isn't by reading your message --
a (maybe write optimized) SSD as a log device could be a solution)
does not solve the issue.
I'll eat ANYTHING that's BRIGHT BLUE!!
http://www.Leidinger.net Alexander @ Leidinger.net: PGP ID = B0063FE7
http://www.FreeBSD.org netchild @ FreeBSD.org : PGP ID = 72077137
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