OK, I think I'm finally settling on some idea of a (desired) tape plan but aren't quite sure how to achieve part of it.
1) Reduce human intervention to absolute minimum by loading up 24-slot tape libary in advance & only swapping out yearly tape
2) Retain Monthly/Yearly backups for archiving
3) Protect disk-based RPs from storage failure
4) Protect monthly tape backups from site failure/disaster
5) Remove requirement to take tapes off-site
My thinking is as follows, based on availability of a 24-slot LTO-6 tape library at each site (local & remote), 1.6Tb full & avg. 25Gb daily incremental:
Source job = Daily Forever Forward (FF) incremental job with Monthly active full on 1st of the month and 90-ish (essentially 3 months) RPs *See note 1 at bottom
Backup copy job = Copies source job to remote site daily with same RPs, probably need GFS job to generate sync'd synthetic monthly fulls (no way to copy active full to remote site over WAN)
Simple Tape Job 1: Daily backup to tape, including incrementals
First full backup to "Simple" media pool, Tape 1 after full source backup on 1st of month,
Subsequent incrementals for that month initially append to the full tape (so same media set) but a 2nd tape available (Tape 2, in same media set) to append to when required (expect to use 1.5 tape/month capacity)
On 1st of Month 2, copy the month 2 active full to a new tape/media set (Tape 3), and again, subsequent incrementals to same tape, plus a 2nd tape (Tape 4) when full
On 1st of Month 3, copy the active full to a new tape/media set (Tape 5), and again, subsequent incrementals to same tape, plus a 2nd tape (Tape 6) when full
On 1st of Month 4, repeat steps for months 2 & the but now overwrite the first pair of tapes (Tape 1 & Tape 2) (My concern here is how to deal with the "overlap" RPs 91 -120 mentioned in note 1 bearing in mind that tape set MUST retain as many RPs as disk set)
Important Note: I'm not worried about All backups for a month being on the same pair of tapes - this is purely protecting against backup storage failure and I plan to repeat this tape plan at the remote site from the backup copy job to the remote site.
My questions are, how can/should I configure things such that a new media set is created either:
A) On the first of the month
B) Whenever a full backup is copied *only* (e.g. never when an incremental backup is copied)
I have only seen options to create a new media set either every time a job runs, or on a specific (or every) day of the week - this isn't flexible enough right now for my needs
One potential kludgy solution to this could be to configure it to "always use same media set" but have a powershell run after the last (incremental) backup of the month & export the tape which should force a new media set to be created, but I'd want/need to be able to automatically import it again after the full backup runs on the next day - is this possible? Would prefer not to have to do this workaround though.
GFS Tape Job 1: Long-term archiving, Monthly fulls only
GFS media pool with retention = 11 Monthly & 7 yearly backups
Create new media set every time the job runs (to keep one monthly .vbk per tape)
Run the GFS job on either the same day as, (or the day after?) the source job monthly full so it just copies the same .vbk file
GFS Tape Job 2: Identical to GFS Tape job 1 BUT, running on remote site to remote site library using backup copy job as source job (to meet requirements 1, 2, 4 & 5)
This plan would utilise 18 slots out of 24 available which leaves me a few slots free for spare tapes in case of failures or unexpected extra backups being run.
Any reasons this strategy wouldn't work? My main concern is managing the media sets for the simple jobs, i.e. keeping the relevant monthly & daily backups together in a set.
*Note1: I basically want to keep up to 3 months worth of RPs on disk, but if I specify 90, with the above plans, I think I'll actually require disk capacity for another full + 29ish incrementals?
[New Sig: PLEASE get GFS tape support for incrementals!!!]