On Thu, Apr 21, 2016 at 01:54:44PM +0800, Hugo Kuo wrote: > Hi Brian, > > Here's the result of xfs_repair on the same disk after rebooting. > https://gist.github.com/HugoKuo/e1d683d9653e66a80dfcfcbee4294fe8 > It's looks normal. > > We rebooted the server and no hanging process in past 12hrs. I'll keep eyes > on the server. > I know it's helpful to to trace-cmd for xfs. But there's too may xfs > operations are happening in the server. It's crazy like 100MB data per > second. I stopped the trace-cmd. As you said, we need to find out the > source of the problem. trace-cmd would be a nice option. Is there a way to > flush recored data if nothing happens in the past hours ? > I'm not sure XFS trace data will help you, at least until we've narrowed down to something that looks like an XFS problem. I wonder if multipath has any sort if tracing support..? It doesn't appear so on a quick look, but dm.c has some trace_block_bio*()/trace_block_rq*() tracepoints that might be useful enough to show whether requests are actually completing. To answer your question, 'trace-cmd record' writes to a local trace.dat file so you don't have to worry about pulling events from the kernel yourself (i.e., as with 'trace-cmd start'). Just make sure you sync or 'xfs_io -c fsync trace.dat' before you force a hard reset, if necessary. Brian > trace-cmd record -e xfs\* > > > > Regards // Hugo > > > > > On Wed, Apr 20, 2016 at 7:24 PM, Brian Foster <bfoster@xxxxxxxxxx> wrote: > > > On Wed, Apr 20, 2016 at 01:49:49PM +0800, Hugo Kuo wrote: > > > Hi XFS team, > > > > > > > > > Here's the lsof output of the grouped result of any openfile happens on > > > problematic disks. The full log of xfs_repair -n is included in this gist > > > as well. The xfs_repair recommend to contact xfs mailing list in the end > > of > > > the command. > > > > > > https://gist.github.com/HugoKuo/95613d7864aa0a1343615642b3309451 > > > > > > Perhaps I should go ahead to reboot the machine and run the xfs_repair > > > again. Please find my answers inlines. > > > > > > > Yes, repair is crashing in this case. Best to try xfs_repair after > > you've rebooted and mounted/umounted the fs to replay the log. If it's > > still crashing at that point, we'll probably want a metadata image of > > the fs, if possible (though there's a good chance a newer xfsprogs has > > the problem fixed). > > > > > > > > On Wed, Apr 20, 2016 at 3:34 AM, Brian Foster <bfoster@xxxxxxxxxx> > > wrote: > > > > > > > > > > > So there's definitely some traces waiting on AGF locks and whatnot, but > > > > also many traces that appear to be waiting on I/O. For example: > > > > > > > > > > Yes, those I/O waiting is the original problem of this thread. It looks > > > like the disk was locked. All these I/O waiting for same disk (a > > multipath > > > entry). > > > > > > > > > > > > > > kernel: swift-object- D 0000000000000008 0 2096 1605 0x00000000 > > > > kernel: ffff8877cc2378b8 0000000000000082 ffff8877cc237818 > > ffff887ff016eb68 > > > > kernel: ffff883fd4ab6b28 0000000000000046 ffff883fd4bd9400 > > 00000001e7ea49d0 > > > > kernel: ffff8877cc237848 ffffffff812735d1 ffff885fa2e4a5f8 > > ffff8877cc237fd8 > > > > kernel: Call Trace: > > > > kernel: [<ffffffff812735d1>] ? __blk_run_queue+0x31/0x40 > > > > kernel: [<ffffffff81539455>] schedule_timeout+0x215/0x2e0 > > > > kernel: [<ffffffff812757c9>] ? blk_peek_request+0x189/0x210 > > > > kernel: [<ffffffff8126d9b3>] ? elv_queue_empty+0x33/0x40 > > > > kernel: [<ffffffffa00040a0>] ? dm_request_fn+0x240/0x340 [dm_mod] > > > > kernel: [<ffffffff815390d3>] wait_for_common+0x123/0x180 > > > > kernel: [<ffffffff810672b0>] ? default_wake_function+0x0/0x20 > > > > kernel: [<ffffffffa0001036>] ? dm_unplug_all+0x36/0x50 [dm_mod] > > > > kernel: [<ffffffffa0415b56>] ? _xfs_buf_read+0x46/0x60 [xfs] > > > > kernel: [<ffffffffa040b417>] ? xfs_trans_read_buf+0x197/0x410 [xfs] > > > > kernel: [<ffffffff815391ed>] wait_for_completion+0x1d/0x20 > > > > kernel: [<ffffffffa041503b>] xfs_buf_iowait+0x9b/0x100 [xfs] > > > > kernel: [<ffffffffa040b417>] ? xfs_trans_read_buf+0x197/0x410 [xfs] > > > > kernel: [<ffffffffa0415b56>] _xfs_buf_read+0x46/0x60 [xfs] > > > > kernel: [<ffffffffa0415c1b>] xfs_buf_read+0xab/0x100 [xfs] > > > > > > > > > > > > Are all of these swift processes running against independent storage, > > or > > > > one big array? Also, can you tell (e.g., with iotop) whether progress > > is > > > > being made here, albiet very slowly, or if the storage is indeed locked > > > > up..? > > > > > > > > There're 240+ swift processes in running. > > > All stuck swift processes were attempting to access same disk. I can > > > confirm it's indeed locked rather than slowly. By monitoring io via > > iotop. > > > There's 0 activity one the problematic mount point. > > > > > > > > > > In any event, given the I/O hangs, the fact that you're on an old > > distro > > > > kernel and you have things like multipath enabled, it might be > > > > worthwhile to see if you can rule out any multipath issues. > > > > > > > > > > > To upgrade the kernel for CentOS6.5 may not the option for the time being > > > but it definitely worth to give it try by picking up one of nodes for > > > testing later. As for the multipath, yes I did suspect some mystery > > problem > > > with multipath + XFS under a certain loading. But it's more like a XFS > > and > > > inode related hence I start to investigate from XFS. If there's no chance > > > to move forward in XFS, I might break the multipath and observe the > > result > > > for awhile. > > > > > > > It's hard to pinpoint something to the fs when there's a bunch of hung > > I/Os. You probably want to track down the source of those problems > > first. > > > > Brian > > > > > > > > > > > > > 'umount -l' doesn't necessarily force anything. It just lazily unmounts > > > > the fs from the namespace and cleans up the mount once all references > > > > are dropped. I suspect the fs is still mounted internally. > > > > > > > > Brian > > > > > > > > > > > Thanks // Hugo > > _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
