Backup size the same across each backup?
- Thread starter droidus
- Start date
@droidus All backups in PVE are full backups. If using PBS, PBS deduplicates on its end when it stores the backups.
Backups will always show the vm data size for each backup.
For instance, in your case each server you have is 32gb is size. Based off of that then theoretically if you had to restore each server then you would need 32gb x # of servers or 100Gb as mentioned above.
Using PBS for the backups then each server is checked for duplicate data and changed data and then compressed in size. In a generalized statement then this might be true -- 32GB of original vm disk space (allocated for the O/S) - 20 Gb of that is 'static' data (never changing) and 5Gb changes daily. Whenever the backup is done it checks for 'duplicate' data from a previous backup and then would only truly back up the 5Gb of space - but still show a 'disk size' for restoration of 60Gb. You can check your backup jobs for information related to what was actually backed up, as well the amt of compression you are getting.
Clear as mud ???
For instance, in your case each server you have is 32gb is size. Based off of that then theoretically if you had to restore each server then you would need 32gb x # of servers or 100Gb as mentioned above.
Using PBS for the backups then each server is checked for duplicate data and changed data and then compressed in size. In a generalized statement then this might be true -- 32GB of original vm disk space (allocated for the O/S) - 20 Gb of that is 'static' data (never changing) and 5Gb changes daily. Whenever the backup is done it checks for 'duplicate' data from a previous backup and then would only truly back up the 5Gb of space - but still show a 'disk size' for restoration of 60Gb. You can check your backup jobs for information related to what was actually backed up, as well the amt of compression you are getting.
Clear as mud ???
I presume you have set your backup jobs to email you whenever they complete like in the shapshot here - 
Within that backup job you should see the backup info and then can see the 'duplicates (reused or not needed), the amt of data that changed, and the compression amt of the whole job.
The 'disk size' will still show (60gb in my example) as backed up, but the 'real' amt of data that DID change and was backed up was 9.32Gb. My compression for this job was 84%
As I've configured and get backup-job logs whenever they complete (good or bad) I haven't tried to search/find where they are kept via the shell. Perhaps someone else can chime in on that info as it'd be good to know. If you haven't created the email section, I would suggest you do that, then take a backup - and you will see what's happening within your logs. You could always create a one-off backup, of something small and then get the job log and apply those email settings to other jobs that you have. I think I currently have 4 different jobs - depending on the type of data and urgency of those servers.
Within that backup job you should see the backup info and then can see the 'duplicates (reused or not needed), the amt of data that changed, and the compression amt of the whole job.
The 'disk size' will still show (60gb in my example) as backed up, but the 'real' amt of data that DID change and was backed up was 9.32Gb. My compression for this job was 84%
As I've configured and get backup-job logs whenever they complete (good or bad) I haven't tried to search/find where they are kept via the shell. Perhaps someone else can chime in on that info as it'd be good to know. If you haven't created the email section, I would suggest you do that, then take a backup - and you will see what's happening within your logs. You could always create a one-off backup, of something small and then get the job log and apply those email settings to other jobs that you have. I think I currently have 4 different jobs - depending on the type of data and urgency of those servers.