Add an option to display the size of a snapshot

[TLINDEN]

Output of restic version

restic 0.12.1 compiled with go1.17.5 on freebsd/amd64

What should restic do differently? Which functionality do you think we should add?

restic snapshots shall display the size of a snapshot (i.e. disk usage), or when a special option like --display-size has been supplied.

What are you trying to do? What problem would this solve?

I am using an external SFTP server as storage backend, which has a limited volume size. I am able to grow it but this adds cost. Currently I only see how much disk space ALL snapshots of ALL hosts are using. However, it may happen that the backup suddenly eats much more backend space than before. In such a case I want to be able to find out which snapshot it was so I can inspect the machine where it came from - AND/OR tune the backend storage size accordingly (before I get errors from restic because the disk is full).

Did restic help you today? Did it make you happy in any way?

Restic helps me a lot, every day! A couple of weeks ago my primary server had a boot slice error and I needed to re-install it. During the process I realized that my backups were incomplete and so I lost data from a half year. Now all my systems use restic and I am more than happy! I already accidently deleted a webserver docroot and could restore it using restic in a couple of minutes. A dream :) !

[MichaelEischer]

I'm not entirely sure what you're asking for. It sounds like the simplest solution would be to check the summary returned by backup --verbose for sudden increases in uploaded data size.

Another option would be to compare the non-deduplicated data size, which would be #693.

Or the question is how much data deleting a snapshot would free, and that is not easy to calculate due to deduplication. But with recent restic versions forget --prune --dry-run <snapshot> would do just that.

The diff command also prints how much data only belongs to one or both of the compared snapshots.

[TLINDEN]

Hello Michael.

I tried the forget --prune --dry-run command, it does the job. I also added the --verbose option to backup. So, from my point of view I am happy.

Thanks a lot!!!

[MichaelEischer]

I guess we should document this somewhere, I had the same question some time ago and didn't immediately think of using forget --dry-run --prune. Anyone up for a PR?

[tribor]

nevertheless, it would be helpful to have a option to restic snapshots (like the mentioned --display-size) to see metrics like

• size of data locally
• size of repo data
• size of data added to repo

for each snapshot. By presenting these metrics you can easily estimate how the repo growth looks like or where deviations/irregularities have occurred.

[MichaelEischer]

@tribor The discussion for that feature belongs into #693.

[huyz]

I guess this should be closed now that #693 has been closed?

[MichaelEischer]

I think so. The snapshot now contains the size of the backed up files as well as the byte uploaded for that specific snapshot.