hmm this seems more serious... i just ran into it with chunksize 64KiB and while just untarring a bunch of linux kernels in parallel... increasing stripe_cache_size did the trick again. -dean On Thu, 27 Dec 2007, dean gaudet wrote: > hey neil -- remember that raid5 hang which me and only one or two others > ever experienced and which was hard to reproduce? we were debugging it > well over a year ago (that box has 400+ day uptime now so at least that > long ago :) the workaround was to increase stripe_cache_size... i seem to > have a way to reproduce something which looks much the same. > > setup: > > - 2.6.24-rc6 > - system has 8GiB RAM but no swap > - 8x750GB in a raid5 with one spare, chunksize 1024KiB. > - mkfs.xfs default options > - mount -o noatime > - dd if=/dev/zero of=/mnt/foo bs=4k count=2621440 > > that sequence hangs for me within 10 seconds... and i can unhang / rehang > it by toggling between stripe_cache_size 256 and 1024. i detect the hang > by watching "iostat -kx /dev/sd? 5". > > i've attached the kernel log where i dumped task and timer state while it > was hung... note that you'll see at some point i did an xfs mount with > external journal but it happens with internal journal as well. > > looks like it's using the raid456 module and async api. > > anyhow let me know if you need more info / have any suggestions. > > -dean - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
