Date: Sat, 01 Jan 2011 23:06:04 -0500 From: "J. Hellenthal" <jhell@DataIX.net> To: Attila Nagy <bra@fsn.hu> Cc: freebsd-fs@freebsd.org, freebsd-stable@freebsd.org, Martin Matuska <mm@freebsd.org> Subject: Re: New ZFSv28 patchset for 8-STABLE Message-ID: <4D1FF9AC.60200@DataIX.net> In-Reply-To: <4D1F7008.3050506@fsn.hu> References: <4D0A09AF.3040005@FreeBSD.org> <4D1F7008.3050506@fsn.hu>
next in thread | previous in thread | raw e-mail | index | archive | help
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 01/01/2011 13:18, Attila Nagy wrote: > On 12/16/2010 01:44 PM, Martin Matuska wrote: >> Link to the patch: >> >> http://people.freebsd.org/~mm/patches/zfs/v28/stable-8-zfsv28-20101215.patch.xz >> >> >> > I've used this: > http://people.freebsd.org/~mm/patches/zfs/v28/stable-8-zfsv28-20101223-nopython.patch.xz > > on a server with amd64, 8 G RAM, acting as a file server on > ftp/http/rsync, the content being read only mounted with nullfs in > jails, and the daemons use sendfile (ftp and http). > > The effects can be seen here: > http://people.fsn.hu/~bra/freebsd/20110101-zfsv28-fbsd/ > the exact moment of the switch can be seen on zfs_mem-week.png, where > the L2 ARC has been discarded. > > What I see: > - increased CPU load > - decreased L2 ARC hit rate, decreased SSD (ad[46]), therefore increased > hard disk load (IOPS graph) > > Maybe I could accept the higher system load as normal, because there > were a lot of things changed between v15 and v28 (but I was hoping if I > use the same feature set, it will require less CPU), but dropping the > L2ARC hit rate so radically seems to be a major issue somewhere. > As you can see from the memory stats, I have enough kernel memory to > hold the L2 headers, so the L2 devices got filled up to their maximum > capacity. > > Any ideas on what could cause these? I haven't upgraded the pool version > and nothing was changed in the pool or in the file system. > Running arc_summary.pl[1] -p4 should print a summary about your l2arc and you should also notice in that section that there is a high number of "SPA Mismatch" mine usually grew to around 172k before I would notice a crash and I could reliably trigger this while in scrub. What ever is causing this needs desperate attention! I emailed mm@ privately off-list when I noticed this going on but have not received any feedback as of yet. [1] http://bit.ly/fdRiYT - -- Regards, jhell,v JJH48-ARIN -----BEGIN PGP SIGNATURE----- iQEcBAEBAgAGBQJNH/msAAoJEJBXh4mJ2FR+bFYH/0bBJbLYU5zzbqpUUXX1M/B9 +g8RwQ9Tek4/fxwpD8DNIfkpzO0MvUcx5Nhwld69jk7sSys9IUpYhuYVggcOgavx sl6AwNNUG0XD/spO2RvV3jD4tVbR6TjlSdLCyBG7iPFU2nNB6wZM+UfWxGYwEyUE loOr13Vk4eU2l2cepUwJH0oGu2hsDZ7qR/fTd+d33NfS6/PT43vbCjPNTsnDJeY9 MdeC5vBUPl3AW3iC/5hxBi9WABGMHeAXTolpAtBQVBNi22mINacYFO6FEdfANy9E Xo207Cd6vBmZb8aTs0BFHs5ZdTHUco/iNysaWvzx9TlIWlyyBRgOXgtBweB+6d4= =lcxW -----END PGP SIGNATURE-----
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4D1FF9AC.60200>