CT checkpoint failed: Interrupted system call

[mr.Scamp]

Hi!

It seems that some CTs cannot be suspended when backup or migration takes place.

root@app1:~# vzctl chkpnt 111
Setting up checkpoint...
        suspend...
Can not suspend container: Interrupted system call
Error: timed out (10 seconds).
Error: Unfrozen tasks (no more than 10): see dmesg output.
Checkpointing failed

Here comes dmesg output:

CPT ERR: ffff88033b65c000,111 :timed out (10 seconds).
CPT ERR: ffff88033b65c000,111 :Unfrozen tasks (no more than 10): see dmesg output.
saslauthd     D ffff88061609e2c0     0  9553   9551  111 0x00800004
 ffff880616797dd8 0000000000000082 0000000000000000 ffffffff8104dc65
 0000000116797e48 0000000000000000 0000000000000000 ffffffffa0441720
 0000000000000286 000000010006a01c ffff880616797fd8 ffff880616797fd8
Call Trace:
 [<ffffffff8104dc65>] ? __wake_up_common+0x55/0x90
 [<ffffffff8109b31e>] ? prepare_to_wait+0x4e/0x80
 [<ffffffffa0434ea3>] dlm_posix_lock+0x193/0x360 [dlm]
 [<ffffffff8109b350>] ? autoremove_wake_function+0x0/0x40
 [<ffffffffa04f6599>] gfs2_lock+0x79/0xf0 [gfs2]
 [<ffffffff811f2123>] vfs_lock_file+0x23/0x40
 [<ffffffff811f27c3>] fcntl_setlk+0x143/0x2f0
 [<ffffffff8153ff4c>] ? thread_return+0xbc/0x870
 [<ffffffff811b2e07>] sys_fcntl+0xc7/0x550
 [<ffffffff81543115>] ? page_fault+0x25/0x30
 [<ffffffff8100b182>] system_call_fastpath+0x16/0x1b

I have tried to reproduce the issue, and discovered that any CT with running saslauthd process inside cannot be suspended.

The FS for CTs is GFS2, the version of Proxmox is:

root@app1:~# pveversion -v
proxmox-ve-2.6.32: 3.1-111 (running kernel: 2.6.32-24-pve)
pve-manager: 3.1-13 (running version: 3.1-13/262cf0b8)
pve-kernel-2.6.32-24-pve: 2.6.32-111
lvm2: 2.02.98-pve4
clvm: 2.02.98-pve4
corosync-pve: 1.4.5-1
openais-pve: 1.1.4-3
libqb0: 0.11.1-2
redhat-cluster-pve: 3.2.0-2
resource-agents-pve: 3.9.2-4
fence-agents-pve: 4.0.0-2
pve-cluster: 3.0-7
qemu-server: 3.1-4
pve-firmware: 1.0-23
libpve-common-perl: 3.0-6
libpve-access-control: 3.0-6
libpve-storage-perl: 3.0-13
pve-libspice-server1: 0.12.4-2
vncterm: 1.1-4
vzctl: 4.0-1pve3
vzprocps: 2.0.11-2
vzquota: 3.1-2
pve-qemu-kvm: 1.4-17
ksm-control-daemon: 1.1-1
glusterfs-client: 3.4.0-2
root@app1:~# dpkg -l | grep gfs2
ii  gfs2-utils                       3.1.3-1                       amd64        Global file system 2 tools

 

[mr.Scamp]

It may be GFS2-related problem,
because the CT is checkpointed successfully when the CTs private area resides on local ext3-formatted partition.