[SOLVED] EACCES: Permission Denied when backing up to PBS.

casparsmit

Active Member
Feb 24, 2015
38
1
28
Hi All,

I seem to have botched my installation of pbs and cannot seem to find the reason why.

whenever i backup a vm it results in:

INFO: starting new backup job: vzdump 100 --node stellar01 --remove 0 --mode snapshot --storage pbs
INFO: Starting Backup of VM 100 (qemu)

INFO: Backup started at 2021-10-13 12:02:08
INFO: status = running
INFO: VM Name: testvm
INFO: include disk 'scsi0' 'local:100/vm-100-disk-0.qcow2' 10G
INFO: backup mode: snapshot
INFO: ionice priority: 7
INFO: creating Proxmox Backup Server archive 'vm/100/2021-10-13T10:02:08Z'
ERROR: VM 100 qmp command 'backup' failed - backup connect failed: command error: EACCES: Permission denied
INFO: aborting backup job
INFO: resuming VM again
ERROR: Backup of VM 100 failed - VM 100 qmp command 'backup' failed - backup connect failed: command error: EACCES: Permission denied
INFO: Failed at 2021-10-13 12:02:08
INFO: Backup job finished with errors
TASK ERROR: job errors


The folders on the datastore are created with the backup:backup credentials (i already tried to chmod 777 everything in the datastore to no avail):

drwxrwxrwx 6 backup backup 4096 Oct 13 11:27 ./
drwxr-xr-x 22 root root 4096 Oct 13 11:53 ../
drwxrwxrwx 1 backup backup 1073152 Oct 13 10:35 .chunks/
drwxrwxrwx 3 backup backup 4096 Oct 13 12:14 host/
-rw-r--r-- 1 backup backup 0 Oct 13 10:35 .lock
drwxrwxrwx 3 backup backup 4096 Oct 13 12:02 vm/

Journalctl shows:


Oct 13 12:23:33 stellar01 pvedaemon[2319]: <stellar@pve> starting task UPID:stellar01:00001D20:00029295:6166B3A5:vzdump:100:stellar@pve:
Oct 13 12:23:33 stellar01 pvedaemon[7456]: INFO: starting new backup job: vzdump 100 --remove 0 --node stellar01 --mode snapshot --storage pbs
Oct 13 12:23:33 stellar01 pvedaemon[7456]: INFO: Starting Backup of VM 100 (qemu)
Oct 13 12:23:33 stellar01 proxmox-backup-proxy[3515]: GET //api2/json/backup?backup-id=100&backup-time=1634120613&backup-type=vm&benchmark=false&debug=false&store=test: 400 Bad Request: [client [::ffff:127.0.0.1]:50282] EACCES: Permission denied
Oct 13 12:23:33 stellar01 pvedaemon[7456]: VM 100 qmp command failed - VM 100 qmp command 'backup' failed - backup connect failed: command error: EACCES: Permission denied
Oct 13 12:23:33 stellar01 pvedaemon[7456]: ERROR: Backup of VM 100 failed - VM 100 qmp command 'backup' failed - backup connect failed: command error: EACCES: Permission denied
Oct 13 12:23:33 stellar01 pvedaemon[7456]: INFO: Backup job finished with errors
Oct 13 12:23:33 stellar01 pvedaemon[7456]: job errors
Oct 13 12:23:33 stellar01 pvedaemon[2319]: <stellar@pve> end task UPID:stellar01:00001D20:00029295:6166B3A5:vzdump:100:stellar@pve: job errors
Oct 13 12:23:40 stellar01 proxmox-backup-proxy[3515]: error during snapshot file listing: 'unable to load blob '"/mnt/vm/100/2021-10-13T10:02:08Z/index.json.blob"' - No such file or directory (os error 2)'
Oct 13 12:23:40 stellar01 proxmox-backup-proxy[3515]: error during snapshot file listing: 'unable to load blob '"/mnt/vm/100/2021-10-13T10:23:33Z/index.json.blob"' - No such file or directory (os error 2)'
Oct 13 12:23:40 stellar01 proxmox-backup-proxy[3515]: error during snapshot file listing: 'unable to load blob '"/mnt/host/stellar01/2021-10-13T10:14:43Z/index.json.blob"' - No such file or directory (os error 2)'
Oct 13 12:23:40 stellar01 proxmox-backup-proxy[3515]: error during snapshot file listing: 'unable to load blob '"/mnt/host/stellar01/2021-10-13T10:15:12Z/index.json.blob"' - No such file or directory (os error 2)'
Oct 13 12:24:00 stellar01 proxmox-backup-proxy[3515]: unable to start task log rotation: EACCES: Permission denied


The directory /mnt/vm/100/2021-10-13T10:02:08Z is created but remains empty.

I can list the repository from the cli:

# proxmox-backup-client list --repository root@pam@127.0.0.1:test
Password for "root@pam": **********
┌────────────────┬─────────────────────────────────────┬──────────────┬───────┐
│ group │ last snapshot │ backup-count │ files │
╞════════════════╪═════════════════════════════════════╪══════════════╪═══════╡
│ host/stellar01 │ host/stellar01/2021-10-13T10:14:43Z │ 2 │ │
├────────────────┼─────────────────────────────────────┼──────────────┼───────┤
│ vm/100 │ vm/100/2021-10-13T10:02:08Z │ 2 │ │
└────────────────┴─────────────────────────────────────┴──────────────┴───────┘

But doing a backup immediatly results in:

# proxmox-backup-client backup mydata.img:/dev/pve/root --repository root@pam@127.0.0.1:test --verbose
Password for "root@pam": **********
Starting backup: host/stellar01/2021-10-13T10:39:00Z
Client name: stellar01
Starting backup protocol: Wed Oct 13 12:39:03 2021
Error: EACCES: Permission denied

PS. I can backup to a freshly installed (other) pbs installation with the same setup with no problem
PS2. I tried removing all proxmox related stuff from the machine and reinstalled everything to no avail.

Any help would be greatly appreciated.
Kind regards,
Caspar
 

casparsmit

Active Member
Feb 24, 2015
38
1
28
After some digging i found out that the culprit was that the /var/log/proxmox-backup/tasks directory was owned by root:root in stead of backup:backup.

Whenever you delete /var/log/proxmox-backup directory it is automatically created upon service restart. The api directory is correctly set to backup:backup but not the tasks directory.
 

casparsmit

Active Member
Feb 24, 2015
38
1
28
Some more digging revealed that the proxmox-backup-daily-update.service creates the /var/log/proxmox-backup/tasks directory with root:root ownership if the directory doesn't exist.

maybe this has already been fixed in newer PBS versions but here's how to reproduce in pbs 1.1.13-2:

1. Stop all proxmox-backup-server services (api/proxy/server etc)
2. rm -rf /var/log/proxmox-backup/*
3. Start proxmox-backup-daily-update service
4. ls -al /var/log/proxmox-backup
5. tasks has root:root ownership.
 

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