RSYNC creates everytime a full-backup instead of incremental backups

[miracuruzrh]

Hi

I love the raspiBackup tool.
Unfortunately I have a little issue. raspiBacku are always performing full backups, although I use the rsync method.
My setup is as follows:
I have a Synolgy 4bay NAS with 4x4TB HDDs. I have created a shared folder on the NAS for raspiBackup to store the files on.
This folder is called "Synology_NetBackup". The sharing of the folder is done with the NFS service.
I've made an entry in /etc/fstab for the folder "Synology_NetBackup". The mountpoint is /mnt/Synology_NetBackup.
Therefore I have also set the variable DEFAULT_BACKUPPATH="/mnt/Synology_NetBackup" accordingly. I call the raspibackup with systemd instead of a cron job. Therefore I have disabled the standard cronjob which the raspibackupUI creates. So far, the backup works. At scheduled time, the systemd service starts raspiBackup and creates a backup.

My only issue is now, that everytime a full-backup instead of a full-backup and then subsequently incremental backups are performed and I was not able to figure out, which option I have setup wrong.

I have attached the latest logfile which I have found in the backup folder and my raspiBackup.conf file as well.

If anyone could point me in the correct direction, what I do wrong or could look into the conf and log files, I would be very thankfull.

Best regards

Simon

raspiBackup.zip

[miracuruzrh]

Or does the incremental backup work after all, and it wasn't obvious to me at first? I have now read about the "hardlinks" and used su -sh * and su -shl * and can now see some differences.

Here I have the result of both queries.

And I think the size of the folders are that large because in each backup also the boot partition and other partitions are backed up as *.img?

╰─○ sudo du -shS *
4.0K    bin
77M     boot
512M    DeskPi-backup.img
4.0K    DeskPi-backup.mbr
4.0K    DeskPi-backup.sfdisk

[framps]

Or does the incremental backup work after all, and it wasn't obvious to me at first?

Yes 😉 You now have discovered the correct commands to use to check whether hardlinks are used and the size of the backups is small.

And I think the size of the folders are that large because in each backup also the boot partition and other partitions are backed up as *.img?

Yes, but it's the small boot partition with 512MB which is not that much and some other small files. If you want so save some additional space for the boot partition check option -B 😉

[miracuruzrh]

Thank you very much for the confirmation. And for the suggestion with -B. Have that also figured out meanwhile and it works nicely. Wish you a pleasent day.

[miracuruzrh]

I still have a bit troubles with understanding the du -sh command. When I went back today for a check, I've got the full 11Gb again, when using the du -sh command on a specific directory. At first glance, I thought there is something wrong. Later on, I have just listed all directories with dh -sh * instead of a particular folder and then it got back to the smaller size of 142Mb. Why is that?

I could guess, when I ask only for one folder, that the command doesn't have any knowledge of the folders, where the hard link points to and therefore just give the result, like it would be the full size? Or is there another explanation?

[framps]

Good catch 👍 I never noticed this behavior before. I frankly don't know because I used this command in the backup directory all the time and the size of all existing backups was displayed.

[framps]

I just found a nice explanation of the effect. It's du which detects reuse of files 😉

[miracuruzrh]

Thank you very much for the link to the explanation and your reply. I didn't found it with my search attempt.