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Reverse Incremental deleting files?

Posted: Dec 19, 2017 3:45 pm
by stdim
afaik the vrb Files are for Reverse Incremental Backups and I think I understand the Concept but not totally.

So as far as I understood it it is like this:
Full Backup is beeing made and (in my case) the changes are Daily written to the Full Synthetic Backup.
If this is right I should have
Now I had read this:
"Additionally, Veeam Backup & Replication creates a reverse incremental backup file containing data blocks that are replaced when the full backup file is rebuilt, and adds this reverse incremental backup file before the full backup file in the backup chain."
"Veeam Backup & Replication “injects” copied data blocks into the full backup file to rebuild it to the most recent state of the VM"
This is a bit Confusing. So as the Name says the Reverse Incremental Backup is the same as the Incremental Backup but backwards.
This Means we have a Base (Full) backup wich gets changes written to it "Injected" every day (my case) and so the Base (Full) Backup is always the most recent thing I can use.
Now we come to the Special part (I THINK SO):
Each time the Changes get "Injected" into the Base (Full) Veaam also saves the old state into these *.vrb files. And we can use these files the "same" way we would do with a normal backup, so if we lets say have the Most recent backup (Friday) we can use this files to downgrade the most recent backup to lets say monday.

Did I undestand this correctly?
If yes my Idea would be to do Reverse Incremental Backups Daily and backup these Backups to Tape (FULL BACKUP) each weekend.
Is this a good approach or would you say thats a bad Idea?

Re: Reverse Incremental deleting files?

Posted: Dec 19, 2017 5:50 pm
by tdewin
You can have the latest VBK send to tape if you want. However if you would use a forever incremental, this is also possible. In this case, a synthetic full will be made directly to tape: ... tml?ver=95

When you do a restore, there is no "downgrade" process. Veeam just opens the file in the chain, and read the correct blocks for the corresponding restore point you have selected from the different files. As such, a restore is instant and also does not modify the original back up files

Re: Reverse Incremental deleting files?

Posted: Dec 19, 2017 11:22 pm
by stdim
So I have a Full Backup and every "dayily backup/part" can be applied to it?
I watched some Videos and Read something about it on the site Here and it says that the full backup is being changed every day.

With synthetic full is meant: Monday (FULL) + Changes over the week.
Thats what I would Like to get the Synthetic Full weekly on tape and then delete the files from last week and create a NEW Full backup.

Re: Reverse Incremental deleting files?

Posted: Dec 20, 2017 9:17 am
by tdewin
Well you can not link the backup job retention directly to a tape out (delete files after the tape job has run). However, you can just put a limited retention count of lets say 14 days on disk, and then a different policy (longer) on tape.

BTW, to clarify, there are nice animations of the different policies for regular backup jobs: