tape retention

You are probably best to set up GFS to tape to take care of all the retention needed - https://helpcenter.veeam.com/docs/vbr/userguide/gfs_jobs.html?ver=13

hi ​@Chris.Childerhose The goal of GFS is create separate MP for Weekly, Monthly and Yearly right? In this case when i want to restore retention on April 5 then i need to mount the GFS MP and daily MP from Jan 01 to April 05, right?

No you would not as GFS tape retention works differently and you would just need the tape that contains that date like the weekly or monthly.

A GFS Media Pool would be the best way to accomplish this. With a GFS media pool, it has 4 pools within it, Daily, Weekly, Monthly and Yearly. 

The tape job will run daily, writing incremental restore points to the daily pool. On days that a weekly, monthly or yearly pools are scheduled, it will copy the full from the source backups job, or synthesize one. 

You can find more about GFS backups here: https://helpcenter.veeam.com/docs/vbr/userguide/gfs_to_tape_hiw.html?ver=13

If you really want to stick to the approach without GFS (to be clear: I also recommend GFS here), you might want to use 1 media pool per retention, so:

1 yearly pool

1 monthly pool

1 weekly pool

Within each pool you will have multiple tapes, satisfying that retention.

Best regards

Lukas

GFS is a single media pool, but it contains media sets for daily, monthly, quarterly, yearly. A media set is simply a logical collection of tapes meant to make it easier for both you and for the software to track what’s on what tape.

Daily media set is always tied to an elder media set (weekly - yearly); if you do not enable weekly though, while the GFS tape job will try to link the daily media set increments to a monthly full, this is not always possible while maintaining chain consistency, so you may end up with periodic full backups in the daily media set.

However, I think this approach may make restorations more complicated. For example, if I need to restore data from April 5, would I need to mount the April monthly tape as well as all daily tapes required to reconstruct the backup chain from January 1 to April 5? Am I understanding this correctly?

No, not correct. Simple media pools that backup increments will always periodically force full backups if the source jobs do not produce full backups on their own. When your source jobs are Forever Forward Incremental (FFI), the tape job targeting a simple media pool will create periodic Virtual Full backups directly on tape (no additional disk space required)

So if you elect simple media sets instead of GFS, your plan will work, the job managing your dailies will ensure that it puts the required fulls on tapes no matter what.

All things considered, probably just go with GFS, less jobs to manage.