There has been some experience with ZIL on an NVRAM device, see http://blogs.sun.com/perrin/entry/slog_blog_or_blogging_on for details.
Regards, Andrey On Tue, Oct 21, 2008 at 12:39 AM, Eric Sproul <[EMAIL PROTECTED]> wrote: > Andrey Kuzmin wrote: >> As to X25-E (released today), this indeed would be a worthwhile try as >> both ZIL and L2ARC device (I believe the latter, if not both, has >> already been explored at Sun). > > Update to my saga: I'm thoroughly disappointed with Mtron 3035 drives, but > maybe they are just not suited for server use at all. The random write > performance is worse than a mechanical drive! > > At this point, we're looking to put ZIL on an NVRAM-based device, the Gigabyte > I-RAM with 4GB of memory (its max.) > http://www.gigabyte.com.tw/Products/Storage/Products_Overview.aspx?ProductID=2180 > > In advance of getting that, I did a rough approximation of its performance by > creating a 4GB file in /tmp and lofi-mounting it. I turned off swap to ensure > the file didn't ever get swapped out of main memory (I have 32GB in this box, > so > it's not an issue, and it's a test system anyway.) > > # zpool destroy data > # swap -d /dev/zvol/dsk/rpool/swap > # mkfile 4g /tmp/slogfile > # lofiadm -a /tmp/slogfile > # zpool create data raidz \ > c0t2d0 c0t3d0 c0t4d0 c0t5d0 c0t6d0 c0t7d0 log /dev/lofi/1 > > Of course, I can't reboot or crash without losing my ZIL, but this is a test > box, and I'd never run it this way in production. Nevertheless, performance > is > impressive, as we expect: > extended device statistics > r/s w/s kr/s kw/s wait actv wsvc_t asvc_t %w %b device > 0.0 6148.2 0.0 786974.6 26.6 3.4 4.3 0.6 86 86 lofi1 > >>6000 write IOPS, or roughly 200x more than we were getting with the Mtrons. > > We'll also be evaluating the Intel X-25E as soon as we can get our grubby > little > hands on one. :) > > Eric > _______________________________________________ > storage-discuss mailing list > [email protected] > http://mail.opensolaris.org/mailman/listinfo/storage-discuss > _______________________________________________ storage-discuss mailing list [email protected] http://mail.opensolaris.org/mailman/listinfo/storage-discuss
