I can elaborate. There are actually a couple different things going on when you have your source backups set as forever incremental. Lets say i keep my retention at 7 points on disk, I need to run backups nightly and get a "full" backup off to tape on fridays.
If my file server backup job is 10 TB my tape job takes 1-2 days to get a backup off to tape because of the size it can't finish before the next normal backup to disk occurs, which causes the tape job to fail. The other issue (Feature) is how to synthesize the full to tape WITHOUT all the incrementals. In my example i only need the 10TB file to disk on friday. Not the 10TB vbk and 6 vib's which would total 14TB. So my options to work around this issue have been:
1. Try and do incremental with synthetic fulls on Friday (transform so i actually have disk space). If the disk IO can keep up this works and i can get it off to tape before the next friday (not the most efficient solution because of IO).
2. Only process the fulls and not process incrementals. This gets the size to tape down to the appropriate size, but i'm always a week behind on tape and can't really control if the VBK is even on a friday as in forever incremental is just goes off the first time it was ran (or new active full) and number of retention points.
* Would be nice sometime to keep 14 retention points and only synthesize latest
friday to tape, what i would love to do, except i would use 10-15 LTO6 tapes per week (and have redundant restore points from week to week)
When someone has large backups to tape that they would like to run weekly, but also get daily backups to disk jobs fail.
Can you elaborate on your request? You have two jobs (backup and backup to tape one), sometimes it happens that the backup to tape job takes longer than expected, and the subsequent run of the backup job fails due to files being locked, correct? And you want to have sort of timeout after which the backup job can proceed smoothly?
Correct. Except i don't want a timeout, i just want the next incremental to run and wait until the tape job finishes before merging.
In my environment besides the job example about i have another 6 backup jobs ranging from 500GB (full) to 2.5TB(full) so you can see how it becomes a compounding concern.
Please keep me posted as this/these are some of the biggest frustations with an otherwise outstanding product.