Backup scheduler retention logic (or underlying files) (noob)

ronejamesdo

Member
Apr 22, 2024
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(This regards making a backup with Proxmox to storage, not the Proxmox Backup Server).

In Datacenter under backup there is one active schedule:

1749822237889.png

Does that reference a schedule in the config files somewhere that I can manipulate?

The most obvious (to me) file, /etc/pve/vzdump.cron, has only:

PATH="/usr/sbin:/usr/bin:/sbin:/bin"

I ask because I have a separate cron job (I should say "I am testing the idea of having") that runs a shell script to run a vzdump after setting all drives that aren't scsi:0 to "backup=0" (and then back again) with the idea that I'll have the nightly backup of everything (using Proxmox) but then also this additional backup of just the OS drive (which I consider useful for servers where the server's content is stored on the secondary drives [in case an OS update breaks something, for example], but where a proper full backup would be useful in a catastrophe).

The script makes the backups (into the same storage as Proxmox does) and apparently becomes part of this flush-out schedule but not in the way I might expect (the script has been running all week and itself deletes nothing):

1749822629159.png

So Promox backups run at 11:30pm and then cron runs mine at 1:00am. All but the most recent of mine seem to be removed by Proxmox at 11:30pm and then my cron job adds a new one at 1:00am.

I expected that either Proxmox would treat mine like its and keep 2 days, the last 3, and one per week, or that it would ignore mine and deal only with its own and mine would just accumulate, or that it would consider mine to be one of its own that it doesn't expect and so the last three "days" would end-up being a day and a half, or maybe just delete all mine as "not supposed to be here". It does not look like it did any of these.

Since the Proxmox internal ran last at 2025-06-12 21:36:10, the newer entry can be ignored. Before that I am struggling to determine what it did to mine. If it keeps the last three backups (before the 2025-06-12 21:36:10 run) then it should keep (my) 2025-06-12 01:00:04 (which it did), (its) 2025-06-11 21:33:09 (which it it did) and (my) 2025-06-11 01:xx:xx (which it did not). If it's not considering mine as a different kind of its own then its 2025-06-09, 10, and 11 should be there (they are), but then so should all of the 01:xx:xx ones that I have made each night.

I'm sure the logic is right in front of me but I just can't put my finger on it.

Additionally the rest of my virtual machines have:

6/12, 6/11, 6/10, 6/9, 6/8, and 6/1

but this one has no 6/1 (and I do not remember deleting it... though that doesn't mean as much as it used to, and it was created on 4/29)

I am hoping that a config file might find me something that I can use to differentiate these but still make use of Proxmox's scheduler (rather than having to complicate my own script with some kind of retention logic and store them somewhere else, etc).

A "restore only X" in the Proxmox web interface would obviously be better but I see no such thing.

Thanks.