On Mon, Jul 23, 2012 at 04:41:53PM +1000, Russell Coker wrote:
there's no benefit in having the ZIL mirrored, but it's probably not worth the hassle of changing it.
http://en.wikipedia.org/wiki/Zfs#ZFS_cache:_L2ARC.2C_ZIL
The below paragraph is from the above Wikipedia page. It seems that mirroring the log device is a really good idea, particularly if it's a SSD.
nice to know, i didn't realise that. will have to look into this in more detail, might have to get another SSD so I can mirror my ZIL. it's probably not urgent though - SSD erase lifetimes are a lot better than they used to be, and also have good wear-leveling algorithms built-in...and most SSDs reserve a sizable percentage of their capacity to 'replace' worn out sections (which is one of the reasons you see 120GB SSDS rather than 128GB)
Also it would be interesting to know whether the zfsonlinux code isn't one of the "earlier versions of ZFS" mentioned.
nope. zfsonlinux is based on the latest version 28 ZFS, the most-recent (and probably last) open source release from Oracle....same as what illumos and recent versions of freebsd have. due to oracle's abandoment of open solaris and related technologies, illumos etc have effectively forked zfs and all future open-source improvements will come from there (the zfsonlinux project is a participant in that process). craig -- craig sanders <cas@taz.net.au>