Re: [MooseFS-Users] High disk usage inside vm makes moosefs read only

[<ma...@me...>]

W dniu 11.01.2017 o 17:54, ma...@me... pisze:
> Hi!
> I'm using moosefs-3.0.86 on ubuntu 16. This is two node setup. On second
> node - node without mfsmaster, only with mfschunkserver, I'm starting
> qemu VM (parameters for qemu:  [...] -drive
> file=/var/lib/one//datastores/101/42/disk.0,format=qcow2,if=none,id=drive-virtio-disk0,cache=none
> -device
> virtio-blk-pci,scsi=off,bus=pci.0,addr=0x5,drive=drive-virtio-disk0,id=virtio-disk0,bootindex=1,logical_block_size=512,physical_block_size=4096
> [...] )
> 
> When high I/O starts inside VM then qcow file with vm image becomes
> unreadable. OS inside qemu hangs. When I run md5sum on qcow file it also
> stuck in D state after reading some part of file.
> There is nothing suspicious in syslog. On mfsmaster I have:
>> Jan 11 16:57:27 w2t-cl-a-00 mfsmount[15828]: high packet travel time between client and master (0.248819s) - ignoring in time sync
>> Jan 11 17:00:00 w2t-cl-a-00 mfsmaster[2501]: no metaloggers connected !!!
>> Jan 11 17:00:03 w2t-cl-a-00 mfsmaster[2501]: child finished
>> Jan 11 17:00:03 w2t-cl-a-00 mfsmaster[2501]: store process has finished - store time: 3.750
> 
> [here, about 17:25 vm stuck in D state]

In dmesg I've got:
> [ 3960.108053] INFO: task qemu-system-x86:25093 blocked for more than 120 seconds.
> [ 3960.108169]       Not tainted 4.4.0-59-generic #80-Ubuntu
> [ 3960.108255] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
> [ 3960.108366] qemu-system-x86 D ffff880053a2fd38     0 25093      1 0x00000000
> [ 3960.108373]  ffff880053a2fd38 ffffffff81101066 ffff88003562bfc0 ffff88007916bfc0
> [ 3960.108377]  ffff880053a30000 ffff880078cfb3ac ffff88007916bfc0 00000000ffffffff
> [ 3960.108382]  ffff880078cfb3b0 ffff880053a2fd50 ffffffff818343f5 ffff880078cfb3a8
> [ 3960.108386] Call Trace:
> [ 3960.108396]  [<ffffffff81101066>] ? futex_wait+0x206/0x280
> [ 3960.108402]  [<ffffffff818343f5>] schedule+0x35/0x80
> [ 3960.108405]  [<ffffffff8183469e>] schedule_preempt_disabled+0xe/0x10
> [ 3960.108409]  [<ffffffff818362d9>] __mutex_lock_slowpath+0xb9/0x130
> [ 3960.108412]  [<ffffffff8183636f>] mutex_lock+0x1f/0x30
> [ 3960.108416]  [<ffffffff8132335a>] fuse_file_write_iter+0x7a/0x2e0
> [ 3960.108421]  [<ffffffff8120e11b>] new_sync_write+0x9b/0xe0
> [ 3960.108425]  [<ffffffff8120e186>] __vfs_write+0x26/0x40
> [ 3960.108428]  [<ffffffff8120eb09>] vfs_write+0xa9/0x1a0
> [ 3960.108432]  [<ffffffff8120f975>] SyS_pwrite64+0x95/0xb0
> [ 3960.108436]  [<ffffffff818384f2>] entry_SYSCALL_64_fastpath+0x16/0x71