On Jul 31, 2010, at 8:56 PM, Gregory Gee wrote: > I was thinking of adding an SDD ZIL to my pool, but then read this in the > 'Best Practice Guide'. > > ********* > Prior to pool version 19, if you have an unmirrored log device that fails, > your whole pool is permanently lost. > Prior to pool version 19, mirroring the log device is highly recommended. > *********
This depends on the failure mode, of course. > > I have the following. > > ********* > ad...@nas:~$ zpool upgrade > This system is currently running ZFS pool version 14. > > All pools are formatted using this version. > ********* > > This really worries me. For a home server, mirrored SSD ZIL is pricey. I > assume this means upgrading to a dev version? What do people do now for > upgrades? Yes, until the OpenSolaris dev's ran dry in February. There are other distributions with later releases. See http://www.genunix.org > > Then, when trying to figure out the size if the SSD, I got this from the > guide as well. > > > ********* > The maximum size of a log device should be approximately 1/2 the size of > physical memory because that is the maximum amount of potential in-play data > that can be stored. For example, if a system has 16 Gbytes of physical > memory, consider a maximum log device size of 8 Gbytes. > > ********* > > I don't think I can get SSD that small. It seems like a waste of larger SSD > now. Is there a way to make better use of the SDD by partitioning? I have > two pools, could I partition the SSD to have each partition as a ZIL for the > different pools? Any other creative uses? I use something like an Intel X-25V (40GB) for boot disk and separate log. There are a number of similar-sized SSDs targeting the boot environments that are in the 32-40 GB size and around $120 or so. -- richard -- Richard Elling rich...@nexenta.com +1-760-896-4422 Enterprise class storage for everyone www.nexenta.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
