We have a client who has nightly (weekdays) backup job and a subsequent backup copy job to rotated USB media. I've tried reading knowledge base articles and trawled through forums etc, I just can't get to grips with how retention should be set. Here's a full breakdown of my exact scenario:
Backup job = Nightly (Weekdays) reversed incremental to Synology NAS via iSCSI - 10 restore points. (Runs at 18.00, usually takes up to 2 hours)
Backup copy job (uses the above job as source) copies every day at midnight to one of 5 USB disks* plugged into the aforementioned Synology, set to keep 2 restore points, no pre or post job scripts, auto retention etc.
*the 5 x USB disks are part of a CIFS (SMB) repo with the "this repository is backed by rotated media hard drives" option ticked
On each of the USB disks there a 4 or 5 x VBK and VIB files as well as one VBM file, hwever
Veeam Version: 22.214.171.1248 (was on Build 126.96.36.1994 until I started looking into this)
So my main question is this. When we are setting the retention of the backup copy job, should i be setting it to 10 (which equates to 2 per disk)? Or is it a retention setting per USB disk? As you can see I'm confused. Second part of my question is, as it's stands could it be that the build up of VBK and VIB files on this disk is because they are outside of the retention chain and therefore not reference by Veeam in any way once the disk is plugged in a week later?
Please let me know if I need to explain things better