segfault / VM crash on backup

Faris Raouf

Well-Known Member
Mar 19, 2018
147
26
58
I'm having some interesting problems with the beta. Essentally, when I run a backup via PVE, the VM crashes and I see a segfault in the host node syslog.

Here's what I did:
I have two nodes in a cluster, both with local storage only.
In PVE, I created a VM and installed PBS from the ISO (all ext4). No problem All good.
In the PBS VM, I manually created a directory /backupstorage via CLI
In the GUI, I created a Datastore to use that location.
I then created a user and gave it a role of DatastoreBackup
No problems so far.

On one of my nodes:
I installed pbs-backup-client, added the pbs storage / fingerprint / user and so forth.

Code:
# pvesm status --storage pbsbackup
Name             Type     Status           Total            Used       Available        %
pbsbackup         pbs     active       184216960         1538660       173250948    0.84%

All looked good so far.

pbsbackup appeared as a storage on my second node as well, but was greyed out until I installed pbs-backup-client on that node as well.

So, all looked good to me. I was happy. Then I tried doing a backup to the new storage via the PVE GUI and things started to go wrong.

Code:
INFO: starting new backup job: vzdump 102 --mode snapshot --remove 0 --compress zstd --node msw2 --storage pbsbackup
INFO: Starting Backup of VM 102 (qemu)
INFO: Backup started at 2020-07-11 14:09:48
INFO: status = running
INFO: VM Name: vm102
INFO: include disk 'scsi0' 'local-lvm:vm-102-disk-0' 50G
INFO: backup mode: snapshot
INFO: ionice priority: 7
INFO: creating pbs archive on storage 'pbsbackup'
INFO: issuing guest-agent 'fs-freeze' command
INFO: issuing guest-agent 'fs-thaw' command
ERROR: VM 102 not running
ERROR: VM 102 qmp command 'backup' failed - client closed connection
ERROR: Backup of VM 102 failed - VM 102 qmp command 'backup' failed - client closed connection
INFO: Failed at 2020-07-11 14:09:49
INFO: Backup job finished with errors
TASK ERROR: job errors

I note that it says VM102 not running. But is IS running, or it was when I started the backup! The VM dies during this period, however, and has to be started to get it up and running again.

This is what I see in the syslog (this entry is from a different VM -- 101 in this case - but ignore that, it is just what I have on hand - the same result for 102):

Code:
Jul 11 13:55:05 msw1 pvedaemon[1135]: <root@pam> starting task UPID:msw1:00003D87:0005B38F:5F09B6A9:vzdump:101:root@pam:
Jul 11 13:55:05 msw1 pvedaemon[15751]: INFO: starting new backup job: vzdump 101 --remove 0 --node msw1 --compress 0 --storage pbsbackup --mode snapshot
Jul 11 13:55:05 msw1 pvedaemon[15751]: INFO: Starting Backup of VM 101 (qemu)
Jul 11 13:55:06 msw1 kernel: proxmox-backup-[15767]: segfault at 55b60cf3d585 ip 00007fc9ec828e08 sp 00007fc8ceb15b40 error 7 in libproxmox_backup_qemu.so.0[7fc9ec74f000+357000]
Jul 11 13:55:06 msw1 kernel: Code: 10 4c 89 7c 24 18 48 8b 43 10 48 85 c0 74 06 c7 00 ff ff ff ff 48 8b 6b 18 48 85 ed 74 2a 4c 89 f7 4c 89 fe ff 15 78 01 46 00 <48> 89 45 00 31 ed eb 19 48 8b 43 10 48 85 c0 74 05 8b 4e 04 89 08
Jul 11 13:55:06 msw1 pvedaemon[15751]: VM 101 qmp command failed - VM 101 qmp command 'backup' failed - client closed connection
Jul 11 13:55:06 msw1 pvedaemon[15751]: VM 101 qmp command failed - VM 101 not running
Jul 11 13:55:06 msw1 pvedaemon[15751]: ERROR: Backup of VM 101 failed - VM 101 qmp command 'backup' failed - client closed connection
Jul 11 13:55:06 msw1 pvedaemon[15751]: INFO: Backup job finished with errors
Jul 11 13:55:06 msw1 pvedaemon[15751]: job errors

I'm also unsure where to look for any further log info on the backup.

Everything should be up to date on the host node:
Code:
# pveversion --verbose
proxmox-ve: 6.2-1 (running kernel: 5.4.44-2-pve)
pve-manager: 6.2-6 (running version: 6.2-6/ee1d7754)
pve-kernel-5.4: 6.2-4
pve-kernel-helper: 6.2-4
pve-kernel-5.3: 6.1-6
pve-kernel-5.4.44-2-pve: 5.4.44-2
pve-kernel-5.4.44-1-pve: 5.4.44-1
pve-kernel-5.4.41-1-pve: 5.4.41-1
pve-kernel-5.3.18-3-pve: 5.3.18-3
ceph-fuse: 12.2.11+dfsg1-2.1+b1
corosync: 3.0.4-pve1
criu: 3.11-3
glusterfs-client: 5.5-3
ifupdown: 0.8.35+pve1
ksm-control-daemon: 1.3-1
libjs-extjs: 6.0.1-10
libknet1: 1.16-pve1
libproxmox-acme-perl: 1.0.4
libpve-access-control: 6.1-1
libpve-apiclient-perl: 3.0-3
libpve-common-perl: 6.1-3
libpve-guest-common-perl: 3.0-10
libpve-http-server-perl: 3.0-5
libpve-storage-perl: 6.1-8
libqb0: 1.0.5-1
libspice-server1: 0.14.2-4~pve6+1
lvm2: 2.03.02-pve4
lxc-pve: 4.0.2-1
lxcfs: 4.0.3-pve3
novnc-pve: 1.1.0-1
proxmox-mini-journalreader: 1.1-1
proxmox-widget-toolkit: 2.2-9
pve-cluster: 6.1-8
pve-container: 3.1-8
pve-docs: 6.2-4
pve-edk2-firmware: 2.20200531-1
pve-firewall: 4.1-2
pve-firmware: 3.1-1
pve-ha-manager: 3.0-9
pve-i18n: 2.1-3
pve-qemu-kvm: 5.0.0-4
pve-xtermjs: 4.3.0-1
qemu-server: 6.2-3
smartmontools: 7.1-pve2
spiceterm: 3.1-1
vncterm: 1.6-1
zfsutils-linux: 0.8.4-pve1
 
pve-qemu-kvm: 5.0.0-4

You're using the enterprise repository, which is still missing the latest updates regarding the Proxmox Backup Server integration.
The only got to pve-no-subscription this week, so we plan to move them early next week if no issue shows up.

Until then please use a non-production PVE setup with the pvetest or pve-no-subscription repository to test the Proxmox Backup Server integration. Thanks!
 
Ah! Unfortunately my non-production setup has to mirror my production setup (pbs being an exception because I couldn't wait to test!) so that I can test updates in the lab before pushing them to the production machines.

So I will simply have to be patient and await their appearance in the enterprise repo.
 
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