On Sat, May 2, 2009 at 12:11 PM, Alan Cox <[email protected]> wrote: > On Fri, May 1, 2009 at 6:28 PM, Freddie Cash <[email protected]> wrote: >> On Fri, May 1, 2009 at 4:12 PM, Louis Kowolowski >> <[email protected]> wrote: >> > On May 1, 2009, at 1:53 PM, Pete French wrote: >> >> ... >> >> The tuning isn't there to improve performance, it's there to prevent >> >> the box going titus due to a panic when the ARC gets too big, and >> >> you are missing the mian one, which is to limit the size of the ARC. >> >> On recent versions of BSD (and you are running 7.2, so thats fine) then >> >> the defaults for kmem size are fine, but you still need something like >> >> this: >> >> >> >> vfs.zfs.arc_max="256M" >> >> >> >> In there to stop the ARC growing. thats the only tuning I have on >> >> my 4 gig machine, which takes a steady stream of data and is used >> >> for taking backup snapshots. ZFS is excellent, and for me is perfectly >> >> stable, to the point where I am starting to roll it out to production >> >> machines, with the above tuning. >> >> >> > I agree, although I'm using 384 instead of 256. My systems have been >> > running in production for almost a year now w/o any ZFS issues. >> >> The exact value to use will depend on the system. Particularly on the >> amount of RAM in the system, and what kmem_max is set to. A >> "rule-of-thumb" we've been using is: >> kmem_max should be half of the amount of RAM (or 1.5 GB as that's >> the current max) > > This information is outdated. The current max in RELENG_7 for amd64 is > ~3.75GB.
Nice! Good to hear. Thanks for the correction. Looking forward to testing this with 7.2. -- Freddie Cash [email protected] _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[email protected]"
