Tape GFS, know which tape to use

[roland]

I need some precision on backup to tape with GFS media pool.
(Especially because of v13 and it's end of Reverse incremental support)

The main goal for tape is to achieve the offsite/offline copy objective of 32110 rules.
It's better to have a minimal number of tapes to restore the complete site in case of disaster recover. (ie the last tape should be full backup or virtual full)

Is GFS media pool the good configuration for this ?
In a scenario with 14 daily, 4 weekly, 12 monthly, 2 yearly, how many tapes do we need (32?) (we suppose one tape is sufficient for a full backup) ?
How to know which tapes needs to be exported, which one need to be present in the tape library ?
Thx

[david.domask]

Hi roland,

Just a quick note, we have a calculator for Tapes which can help with the tape planning.

Each media set (daily, weekly, monthly, yearly) will need its own tapes, a tape cannot be part of two media sets at once, so you would plan your tape usage based on how often you need to rotate tapes and how much data you have to tape-out.

Tape export depends on your export strategy, but it's pretty common to export based on the media set, for example perhaps exporting the weeklies and monthlies at the same time each month (just an example, this is entirely up to your needs)

Which tape is required depends on the media set options regarding media set creation. (Under Advanced on this tab) -- by default, a new media set will be created each backup session for the elder media sets, meaning a new tape each weekly-yearly backup. Daily by default is "Append", meaning the same tape will be used each time until the tape is full.

Play with the calculator a bit and review the User Guide links above, and if there are further questions we can help.

[roland]

Just a quick question,
if a tape is marked as expired, does it means that all block on it are not need anymore by the system to assume the GFS retention ?
So the global chain is stored (to assume all required retention points) on the other protected tapes ?

[david.domask]

Tape retention is based on the backup set with the longest retention configured. See the examples on the page there to understand better how the tape retention works.

So yes, a tape does not fall out of its retention period until the backup set on that tape with the longest retention is out of retention, as it means all of the backup sets on that tape fall outside of the retention period.

[roland]

Thanks David