In an attempt to answer your questions:
1) if i delete/expire those dedup images, would they also expire the backups contained in the tapes?
- Yes, if you choose to expire the image ID and not specify a copy number, then all copies of a particular backup image could be accidentally expired.
2) i have been processing transaction queues but only gained a minimal free space. nothing dramatic. is this the way?
- Yes. If you've slowly been creeping towards MSDP full, then running queue processing manually isn't really going to give you much back - unless you get lucky and you just so happen to run queue processing after a big old random data test backup just so hapenned to expire and then you purged it using queue processing - and then you'd think queue processing did the trick, but all it was... was random luck.
3) how to really delete the dedup images for non-production servers? the only TN i can find is this https://www.veritas.com/support/en_US/article.TECH124914
- Look at my post above. Deleting some older copies of backups that typically dedupe very well will most probably not bring much space back.
4) lastly, is my plan advisable? like unless the ordered disks arrive, i don't have any way to add more hd space.
- Your options are:
4a) Cease backups of some entire sets of clients AND expire all of their backups from disk - but... here's a known unkown... if a bunch of clients in SetA have similar backup data, i.e. dedupe well against a bunch of clients in SetB, then again... ceasing backups for all clients in SetA and expiring all backups (on MSDP) for all clients in SetA - still won't bring you back much MSDP space - because the bunch of clients on SetB still referenced the very same dedupe blocks.
4b) Acquire more storage.
4c) Delete / remove a lot of old superfluous data from backup clients.
4d) Renegotiate what you backup (i.e. what goes in your backup policy selection lists).
4e) Backup some non-production poor dedupe jobs directly yo tape and so avoid landing in the MSDP pool.