Comment 3 for bug 768080

Hi,

I've also experienced this problem. In my case I did a backup last WE, and did another one today: sbackup decided to do an incremental backup, which should be very small (actually empty) as pretty much no file changed in the last 90 days:

$ find /home/musique/ -ctime -90
/home/musique/
/home/musique/.config
/home/musique/.config/autostart
/home/musique/.config/autostart/indicator-weather.desktop

sbackup does think there is almost nothing to backup:

2011-10-22 10:11:07,092 - INFO: Last full backup is fresh (42 days old )-> make an increment
2011-10-22 10:11:07,093 - INFO: Instantané '2011-10-22_10.11.07.092778.workstation.inc' en cours de création.
2011-10-22 10:11:07,093 - INFO: Réglage de la Base à '2011-10-16_10.54.21.443230.workstation.inc'.
2011-10-22 10:11:07,093 - INFO: Réglage des fichiers de sauvegarde.
2011-10-22 10:11:07,233 - INFO: Réglage des exclusions de fichiers.
2011-10-22 10:11:07,233 - INFO: Réglage du format de compression à `0`
2011-10-22 10:11:07,234 - INFO: L'option 'Suivre les liens symboliques' est désactivée.
2011-10-22 10:11:07,234 - INFO: Inspection du système de fichiers et collecte des informations sur les fichiers
2011-10-22 10:11:08,956 - INFO: Résumé de la sauvegarde
2011-10-22 10:11:08,956 - INFO: Nombre de répertoires : 1026.
2011-10-22 10:11:08,956 - INFO: Nombre total de fichiers : 2837.
2011-10-22 10:11:08,956 - INFO: Nombre de liens symboliques : 0.
2011-10-22 10:11:08,956 - INFO: Nombre de fichiers inclus dans l'instantané : 1.
2011-10-22 10:11:08,957 - INFO: Nombre de nouveaux fichiers (également inclus) : 1.
2011-10-22 10:11:08,957 - INFO: Nombre de fichiers ignorés dans l'instantané incrémental : 2836.
2011-10-22 10:11:08,957 - INFO: Nombre de fichiers exclus de force : 0.
2011-10-22 10:11:08,957 - INFO: Nombre de fichiers exclus selon la configuration : 0.
2011-10-22 10:11:08,957 - INFO: L'espace libre maximum requis est '0 Mo 513 Ko 800'.

However the tar file is 9.6GB so far, and still growing. I've had this before and sbackup basically ended up doing a full backup.

I tried running the tar command sbackup uses -- I simply added a "-f /tmp/test.tar" to make things simpler and "-v" to see which files it backs up:

# /bin/tar -cS --directory=/ --ignore-failed-read --blocking-factor 20 --totals --files-from=/tmp/sbackup/includes.list --exclude-from=/tmp/sbackup/excludes.list --listed-incremental=/tmp/sbackup/files.snar -f /tmp/test.tar -v

Now if I add "--no-check-device", it pretty much doesn't backup anything apart from the folders (the file structure, not the file themselves), and I end up with a backup of 1.1MB:

# /bin/tar -cS --directory=/ --ignore-failed-read --blocking-factor 20 --totals --files-from=/tmp/sbackup/includes.list --exclude-from=/tmp/sbackup/excludes.list --listed-incremental=/tmp/sbackup/files.snar -f /tmp/test.tar -v --no-check-device
/home/musique/.config/
/home/musique/.config/autostart/
[...]
/home/musique/tmp/tmp/
Nombre total d'octets écrits: 1116160 (1,1MiB, 7,5MiB/s)

So I can only assume that the device number changes (see http://www.gnu.org/software/automake/manual/tar/Incremental-Dumps.html for more details) on my setup which has LVM on top of a software MD RAID 1 (created with mdadm).

Can I therefore suggest to add this option "--no-check-device" to tar by default, and ideally make it configurable?

Regards,
Thibault.