Re: ZFS & Bittorent -> Hang?
No problem. I've filed a PR: http://www.freebsd.org/cgi/query-pr.cgi?pr=122888 This doesn't seem to be a volume-of-data thing, not sure if it is related to using raidz or not. I don't have another spare disk in the machine I tested on to pare things down. Otherwise, seems to be pretty stable. I've been knocking on it for some time with no other troubles. Prefetch seems to me to be a little less than ready for prime-time. I seem to recall on a 32-bit machine as well that pkg_delete would run terribly slowly with prefetch on, and things got better when I re-enabled the zil and turned prefetch off. Not sure whether the zil just helped a lot there or if the problem was prefetch. I'm using ZFS on my Mac OS X laptop as well, that's been pretty good too. Latest build (111 on zfs.macosforge.org) has fixed mmap coherency, and a bunch of other things. On Fri, Apr 18, 2008 at 1:03 PM, Claus Guttesen <[EMAIL PROTECTED]> wrote: > > OK. I've been able to reproduce the issue. > > > > Conditions: > > - Stock shipped kernel and modules from RELENG 7.0 > > > > loader.conf settings: > > - zfs prefetch enabled > > - zfs zil disabled > > - vm.kmem_size_max="1073741824" > > - vm.kmem_size="1073741824" > > > > AMD64 on Core 2 Duo w/ 4 GB RAM > > > > raidz across 4 disks, using root on zfs (also experienced this hang with > zfs > > just on /usr) > > > > How To Reproduce > > - install transmission-daemon, run transmission-daemon (it will daemonize, > > automatically backgrounding) > > - grab a torrent, such as KNOPPIX (http://torrent.unix-ag.uni-kl.de/) > > - transmission-remote -a (add the torrent) > > - transmission-remote -s all (start all the torrents) > > > > wait hours to a day or so with whatever you want logging things running > and > > active since anything that hits disk after the hang will get hung as well > > > > I've just done this twice. It doesn't seem to happen with zil enabled and > > prefetch off. > > > > Expected Behavior > > No hang. > > Thank you for spending time on this. I'm getting some jbod-storage in > a few weeks and will spend some time using various block-sizes and > share partitions across nfs. I'm somewhat confident that zfs on > FreeBSD will work fine but Solaris is (of course) also an option. This > will be approx. 7 TB to begin with and growing upwards to some two > digit TB's. > > What is the largest storage zfs on FreeBSD has been used on? I tried > it for some month on 8 TB. > > -- > > > regards > Claus > > When lenity and cruelty play for a kingdom, > the gentlest gamester is the soonest winner. > > Shakespeare > -- James Snyder Biomedical Engineering Northwestern University [EMAIL PROTECTED] ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
Re: ZFS & Bittorent -> Hang?
Thanks for the followup. I have not yet gotten a reliable test case to reproduce the problem. I've done a number of tests with the zil and/or prefetch on with no hangs. I will be collecting some more data later this week. If anyone knows a source of consistently slow but large torrents (I suppose I could artificially limit bandwidth, or connection states at my router which is running pfSense), that might help for testing. The process that triggered things before was about a gigabyte or two but took around 12 hours to complete. Here's the overall group of variables I'm experimenting with. Stock Kernel vs Recompiled Kerel w/ ULE (stock sources otherwise) ZIL on and off prefetch on and off Should I add or remove anything? I have no idea if ULE may or may not play a role here, but my original failing condition had the zil off, prefetch on, ule for the scheduler. I also had: vm.kmem_size_max="1073741824" (loader.conf) vm.kmem_size="1073741824" (loader.conf) Any recommendations on what to leave running to record what zfs is getting hung on, beside watching states? Since I can fire up things prior to the hang, and they'll keep running if disk isn't hit, I could leave some diagnostics running to display what's blowing up. Thanks! On Tue, Apr 15, 2008 at 4:44 AM, Claus Guttesen <[EMAIL PROTECTED]> wrote: > > > http://wiki.freebsd.org/ZFSKnownProblems > > > > > > This looks like #1. > > > > > > > Hmm.. I don't think there's a large amount of transfer between UFS & ZFS, > > unless the client is using /tmp a lot, it should all be on ZFS. > > > > I noted #4 as well, and therefore tried disabling prefetch. I can't seem > to > > get it to hang now. I queued up a bunch of different torrents (full > freebsd > > 7 amd64 & i386, some other random things), and they all completed without > > leading to me being locked out or any processes waiting on zfs. > > > > I'll try some testing this weekend to see if I can reproduce the lock-up > > again by re-enabling prefetch. Perhaps we can confirm that issue? > Should I > > bother with trying to run CURRENT or should any testing I do be done with > > STABLE. I don't see any indication that there might be experimental > patches > > for dealing with this or related issues. > > Were you able to reproduce the lock-up by re-enabling prefetch? > > -- > regards > Claus > > When lenity and cruelty play for a kingdom, > the gentlest gamester is the soonest winner. > > Shakespeare > -- James Snyder Biomedical Engineering Northwestern University [EMAIL PROTECTED] ___ freebsd-stable@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-stable To unsubscribe, send any mail to "[EMAIL PROTECTED]"
