RaspiBackup ends with Error RBK0021E; RC2

[Mercur13]

I've been using RaspiBackup for half a year for a weekly automatic backup with tar to an SSD (128GB).
This has worked great so far. Unfortunately the above error occurred yesterday. Unfortunately, the list of error messages from the framps homepage does not give any indication (except that "some bad error" occurred. That's why I looked for other abnormalities in the RaspiBackup environment. I noticed that the backup target (SSD 128GB) "only" still 11GB free space To avoid running out of memory, I deleted some old backup files and promptly got 44GB free space.
RaspiBackup carried out again .... and success!
Apparently, RaspiBackup temporarily requires much more storage space than the "finished" backup file suggests.

@framps: Maybe a hint about a possible lack of memory with the above error message would be helpful for other users.
RaspiBackup should check when it starts whether there is enough storage space on the target and if there is insufficient storage space, abort the program with this message (and not only after it has run for 15 minutes).

[framp]

You meant to tag
@framps

[Mercur13]

Sorry framp !

[framps]

Thank you very much for your feedback 👍

I see your point. Unfortunately RC2 is a very unspecified error Fatal error. This means that some fatal, unrecoverable error occurred. I will update the description of RC2 and point to this root cause also.

Actually I'm surprised because raspiBackup should write also the tar error which I expect to more precise 🤔 Would you please check? But please use the most current raspiBackup release for this (sudo raspiBackup.sh -U -S will update to the latest release).

Anyhow keep in mind the backup cleanup happens at the end of a successful backup run and thus you have to have at least space for an additional backup whenever you start a backup run.

It's very time consuming and not very easy to calculate the required space for the next backup. You're the first who faces this issue - mostly because you either keep to many backups for your available backup space or all of the sudden your backup increased significantly for some reasons.

As an alternative and that's much more easier to implement I can check at the and of a backup run either for a percentage of free space (e.g. 20% free space) or a given amount of free space (e.g. 80GB free space) and write a warning message if the free space is no longer available. Does this sound to be a good alternative for you?