Though you are looking for two things we will answer all three here.
1. I've checked total disk usage for all our libraries and it totals to 219TB, whereas our licence capacity is currently at 136TB. This doesn't seem right to me. Would this be normal?
-- This is happening because we are saving with deduplication.
2. In the short term, I want to free up some space in order to have our backups continue uninterrupted. I currently have our monthly tape copies running. What would be the best way to delete jobs from disk that have gone to tape? Just view the jobs on both tape and disk copies and compare job numbers? Is there a quick solution to this? If it helps, our current retention cycle is 4 weeks/30 days, so simply running aging as the tape copies run won't work as a lot of the data will be retained until this period reaches it's limit. Would I simply be able to change the retention period to something like 1 week and run data aging?
-- Data Retention is “Cycles AND Number of days” for example 4 cycles and 30 days so data when meets 4 cycles and also 30 days criteria will be picked for aging (also secondary copy should not be waiting for this data to be copied as well), changing aging criteria will definitely help free up space from primary library.
Note: Cycle one full to next full.
3. I want to work out what's causing the spike in data growth, and what's chewing up all the available space on this particular disk library. I've gone through the reports but I couldn't see anything that would give me a breakdown on individual disk libraries. I've checked our Commcell growth over a 4 week period and it's massive, which worries me.
-- This can be looked at Mount Paths Space Usage and Data Written Distribution by Copies and Space Usage History to know where this data growth is coming from.