Is VLB files a part of backup chain?

[FatlandAndy]

We use an HPE Storeonce as repository, and there is a limit on 14 concurrently opened files which limits our backup chain to max 13 incremental before a new full backup is made. But will transaction log backups count towards this limit? Let's say I backup our SQL server with daily synthetics full and incremental backup every 2 hours. That makes for 12 files in chain (is metafiles does not count). if we also backup transaction logs every 15 minutes, it will amount to 96 extra files. Will we be able to run an restore? (I will test this as soon as setup is complete).

[foggy]

Hi Andreas, VLB files are not counted within the allowed max backup chain limit, you will have a backup chain up to 14 restore points, as specified in the table. Btw, you do not need to apply all 96 transaction log backups upon restore but just those that depend on the corresponding parent restore point - i.e. made within the 2 hours interval between the increments. Overall, as long as the total amount of files required for a particular restore operation doesn't exceed the storage connection limit, you're fine. (The actual restore points chain length limit incurs some connections overhead, to accommodate synthetic fulls, for example, so is not that critical for restores.)

[FatlandAndy]

Thanks for the reply, appreciate it. If I understand you correctly, in a situation where I backup a SQL server with weekly synthetic full and daily increments, and run hourly transaction log backups it will exceed the storeonce limit? I'm not sure that this will be a requirement, but good to know anyhow.

[Andreas Neufert]

There is only one vlb file next to the image level backup file. All transaction log backups between image level backups will be appended to the same vlb file.

As well the access at restore to the vlb file is done after the restore out of the image level backup.