Backup directory /var/backup could not be unmounted

In the backup-directory, mail is stored in folders mailxy (xy=numbers), then the tar-files are also numbered (e.g. mail43_2021-11-22_00-09.tar.gz). These numbers seem to be IDs, that I cannot relate to anyhow in ISPConfig or as user-IDs, as for the web-spaces.
Better:
1. /var/vmail/{domain}/{user}
2. Backup: /var/backup/ispconfig/mail{xy}/mail{st}_$date_$time.tar.gz
Where: domain!=xy and user!=st
Question: How can I relate the two corresponding variables?

 

/var/backup/mailX/mailY...

x = domain_id from mail_domain
y = mailuser_id from mail_user

 

Thank you for that. Is it anywhere in ISPConfig visible, the x and y? Because I don't find it :-(

 

Probably not in ISPConfig panel, but you can look those up in the database. Those identifiers @florian030 gave are dbispconfig database table names and column names.

 

Hello, it's me again :-D thanks for your help till right now. I did find out now the email-domains that it is refering to. Anyway, didn't solve my problem
Would it be better to start a new thread since it's been getting out of hand / too long?

What I know so far:
- every night there is the backup-process running and the unmounting-script is not able to unmount my backup-space, since a process is using the mount-point
- it's always the same maildomain-id: /var/backup/mail18
- the folder is now about 35GB big (is it maybe too much and lasting too long!?)
- the later unmounting works, since my lsof-check is running again and then not failing, so it is triggered too soon obviously!?

Does anybody have more ideas on what to check again or what I am missing?
I'll include the Screenshot of the 3 mails that I'm referring to. Thaaaanks!

By the way: letzte Nacht war seit Monaten das erste Mal, dass der Fehler nicht kam, der lsof-check aber ebenso 2 Mal getriggert wurde