Incrementals backups and deleted files

Virtualmin
1

Hello,
If I have a full backup on sunday and incrementals backups from monday to saturday.
In the the case where one file (fo ex. a video file) is deleted from my website on monday :

  • if I restore the full backup this video wil be restored.
  • if after I restore the incremental backup of tuesday, is the video file wil be deleted ? Or incremental backup does only replace changed files or add new files ? Can it delete files which are no more present on the server ?
    Thanks.
2

I’ll be interested in the answers as well.

You can download your backup, decompress it, find your video and upload it.

3

In theory placing an incremental backup over a full backup/current should only change files (that is add/update) files that do not exist on the current.

At least that is the theory.

I have not tested yet on Virtualmin (I have only restored full backups which work as expected) taking everything back to the timepoint of that backup.

Of course incremental backups are generally thought of as more use in a production environment.

4

What happens when you delete a file? Does this get removed from the incremental or is it there forever?

5

Easy tested, create a example.com and upload a video.
Run full backup on that one domain, the delete video.
Run incremental on that domain.
delete domain
Then restore domain from full backup, check the video should be there.
Then run incremental restore then check if video is there.

6

which it will be

7

Does the incremental need the date format in place to work?

8

No it does not the files are backed up using the file’s state and not date. I’m not sure what bit is set in the file handle, back in the early 1980’s files used to have an archive bit in the file handle which you would set when you backed up the file, when the file was modified this bit was unset

1 Like
9

Tested, yep its still there.

10

Tested to, same result :frowning:

11

What did you want to happen ? File deleted? If so just delete it

12

Imagine you’ve got a php script (phpBB for example).

  • complete backup on sunday
  • update of phpBB on monday where some php files are deleted
  • server crash on wednesday
  • I restore with complete backup of sunday + incremental backup of tuesday. The action will keep php files who are supposed to be deleted…
    Or if yu have a website where user can upload or delete files like pictures or videos… you will have files supposed to be deleted restored. It’s impossible to know which one should be deleted.

What I want to happen is to restore exactly the same situation before the crash.

13

So take a full backup or in your code/db make a record the user activity that is making the changes and rerun those changes which you recover from the current state (or mirror the app)

a lot can happen on a server/active site between any backup

14

What on the virtual servers can crash the server (the php site might not work but thats not crashing the server), or is this hypothetical?

"* update of phpBB on monday where some php files are deleted

  • server crash on wednesday
  • I restore with complete backup of sunday + incremental backup of tuesday. The action will keepphp files who are supposed to be deleted…"

The incremental won’t restore deleted files if there where not there at the time of the backup being made, bit confused here.

I do full backups nightly to AWS, I don’t like the thought of going back a week to restore the full, especially dealing with customers emails. That might be better if your worries about that scenario.