Date: Thu, 21 Jan 2010 15:46:37 -0500 From: Gary Corcoran <gcorcoran@rcn.com> To: Adam McDougall <mcdouga9@egr.msu.edu> Cc: freebsd-fs@freebsd.org Subject: Re: Repeatable ZFS "kmem map too small" panic on 8.0-STABLE Message-ID: <4B58BD2D.30803@rcn.com> In-Reply-To: <4B58A069.8000802@egr.msu.edu> References: <4B58976E.1020402@polands.org> <4B58A069.8000802@egr.msu.edu>
next in thread | previous in thread | raw e-mail | index | archive | help
Adam McDougall wrote: > Put this in /boot/loader.conf: > vm.kmem_size="20G" > > It is intentionally higher than your amount of ram. Would you mind explaining... 1) why this fixes the kmem_map too small problem ? 2) why it should be larger than the amount of RAM, and by how much ? Thanks, Gary > On 01/21/10 13:05, Doug Poland wrote: >> Hello, >> >> I've got an 8.0-STABLE (amd64) box with 4GB RAM. The machine is running >> off a 6-disk RAIDZ1 booting from GPT. The box consistently panics on >> unixbench's fsdisk program. >> >> I have been gathering some metrics in an attempt to isolate the >> parameters that are significant, but I admit I do not really understand >> all the relationships. At this point, I have nothing set in >> /boot/loader.conf >> >> Here are some of the values I was recording within seconds of the panic: >> >> # dmesg | grep memory >> real memory = 4294967296 (4096 MB) >> avail memory = 3961372672 (3777 MB) >> >> kstat.zfs.misc.arcstats.size: 308522248 >> vfs.zfs.arc_max: 829480960 >> vfs.zfs.arc_meta_limit: 207370240 >> vfs.zfs.arc_meta_used: 165575944 >> vfs.zfs.arc_min: 103685120 >> vm.kmem_size: 1327169536 >> vm.kmem_size_max: 329853485875 >> >> # vmstat -m | egrep 'InUse|solaris' >> Type InUse MemUse HighUse >> solaris 491349 1316172K - >> >> % zpool status >> pool: bethesda >> state: ONLINE >> scrub: none requested >> config: >> >> NAME STATE READ WRITE CKSUM >> bethesda ONLINE 0 0 0 >> raidz1 ONLINE 0 0 0 >> gpt/disk0 ONLINE 0 0 0 >> gpt/disk1 ONLINE 0 0 0 >> gpt/disk2 ONLINE 0 0 0 >> gpt/disk3 ONLINE 0 0 0 >> gpt/disk4 ONLINE 0 0 0 >> gpt/disk5 ONLINE 0 0 0 >> >> errors: No known data errors >> >> My concern is if I can panic the box with a simple file system >> benchmark, what will happen when I rysnc files across a 1GB LAN >> connection? I am very willing to run any number of tests and tweek ZFS >> as necessary. Please advise. >>
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?4B58BD2D.30803>