On 21 February, 2010 - Richard Elling sent me these 1,3K bytes: > On Feb 21, 2010, at 9:18 AM, Tomas Ögren wrote: > > > On 21 February, 2010 - Felix Buenemann sent me these 0,7K bytes: > > > >> Am 20.02.10 03:22, schrieb Tomas Ögren: > >>> On 19 February, 2010 - Christo Kutrovsky sent me these 0,5K bytes: > >>>> How do you tell how much of your l2arc is populated? I've been looking > >>>> for a while now, can't seem to find it. > >>>> > >>>> Must be easy, as this blog entry shows it over time: > >>>> > >>>> http://blogs.sun.com/brendan/entry/l2arc_screenshots > >>>> > >>>> And follow up, can you tell how much of each data set is in the arc or > >>>> l2arc? > >>> > >>> kstat -m zfs > >>> (p, c, l2arc_size) > >>> > >>> arc_stat.pl is good, but doesn't show l2arc.. > >> > >> zpool iostat -v <poolname> would also do the trick for l2arc. > > > > No, it will show how much of the disk has been visited (dirty blocks) > > but not how much it occupies right now. At least very obvious difference > > if you add a zvol as cache.. > > > > If it had supported TRIM or similar, they would probably be about the > > same though. > > Don't confuse the ZIL with L2ARC. TRIM will do little for L2ARC devices.
I was mostly thinking about the "telling the backing device that block X isn't in use anymore", not the performance part.. If I have an L2ARC backed by a zvol without compression, the "used" size will grow until it's full, even if L2ARC doesn't use all of it currently. /Tomas -- Tomas Ögren, st...@acc.umu.se, http://www.acc.umu.se/~stric/ |- Student at Computing Science, University of Umeå `- Sysadmin at {cs,acc}.umu.se _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
