Sync from PBS to PBS failed: too many open files


Active Member
Mar 16, 2017
On friday I created a sync job to copy files from PBS-02 to PBS-01
PBS-02 has different datastores and PBS-01 uses the 'new' namespace feature.

Both PBS are running the latest no-subscription version 2.2.5
Updated 29.07.2022 and both rebootet,

On PBS-01 (target) I get:
2022-07-31T18:00:00+02:00: Starting datastore sync job 'pk-pbs-02:backup-61:pk-pbs-01:backup-61:s-25c4e946-498b'
2022-07-31T18:00:00+02:00: task triggered by schedule '18:00'
2022-07-31T18:00:00+02:00: sync datastore 'pk-pbs-01' from 'pk-pbs-02/backup-61'
2022-07-31T18:00:00+02:00: ----
2022-07-31T18:00:00+02:00: Syncing datastore 'backup-61', root namespace into datastore 'pk-pbs-01', namespace 'backup-61'
2022-07-31T18:00:00+02:00: Encountered errors while syncing namespace  - Failed to retrieve backup groups from remote - EMFILE: Too many open files
2022-07-31T18:00:00+02:00: TASK ERROR: sync failed with some errors.

On PBS-02 (source) I get:
nothing, since I had to reboot it this morning, cause of the well known 'iLO bug and the interrupt'.

It worked once on 28.07.2022:
2022-07-28T18:00:00+02:00: Starting datastore sync job 'pk-pbs-02:backup-61:pk-pbs-01:backup-61:s-25c4e946-498b'
2022-07-28T18:00:00+02:00: task triggered by schedule '18:00'
2022-07-28T18:00:00+02:00: sync datastore 'pk-pbs-01' from 'pk-pbs-02/backup-61'
2022-07-28T18:00:00+02:00: ----
2022-07-28T18:00:00+02:00: Syncing datastore 'backup-61', root namespace into datastore 'pk-pbs-01', namespace 'backup-61'
2022-07-28T18:00:03+02:00: found 23 groups to sync

Nothing changed in the configurations.

Any ideas?

Btw. the normal backups are starting at 11pm.
Last edited:


The Proxmox community has been around for many years and offers help and support for Proxmox VE, Proxmox Backup Server, and Proxmox Mail Gateway.
We think our community is one of the best thanks to people like you!

Get your subscription!

The Proxmox team works very hard to make sure you are running the best software and getting stable updates and security enhancements, as well as quick enterprise support. Tens of thousands of happy customers have a Proxmox subscription. Get your own in 60 seconds.

Buy now!