diff --git a/docs/tape-backup.rst b/docs/tape-backup.rst index 5d4ce444..1511ba32 100644 --- a/docs/tape-backup.rst +++ b/docs/tape-backup.rst @@ -987,11 +987,10 @@ Here are a few example setups for how to manage media pools and schedules. This is not an exhaustive list, and there are many more possible combinations of useful settings. -Simple Setup -~~~~~~~~~~~~ +Single Continued Media Set +~~~~~~~~~~~~~~~~~~~~~~~~~~ -The most simple setup, always continue the media-set and never expire. -All backups are stored on a single media set and never deleted. +The most simple setup: always continue the media-set and never expire. Allocation policy: continue @@ -999,20 +998,22 @@ Allocation policy: Retention policy: keep -Such a simple setup has the advantage that it uses not much space, and -since there is only one media-set, it is easy to manage. On the other hand, -it is prone to errors. If a single tape fails, all backups that uses chunks -from that tape will not be restorable. If you want to start a new media-set -manually, you can set the currently writable media of the set either to -'full', or set the location to an offsite vault. In that case, a new -media-set will be created. +This setup has the advantage of being easy to manage and is re-using the benefits +from deduplication as much as possible. But, it's also prone to a failure of +any single tape, which would render all backups referring to chunks from that +tape unusable. + +If you want to start a new media-set manually, you can set the currently +writable media of the set either to 'full', or set the location to an +offsite vault. Weekday Scheme ~~~~~~~~~~~~~~ -A slightly more complex scheme, where the goal is to have a tape for each -weekday, e.g. from Monday to Friday. This can be solved by having a seperate -media pool for each day, so 'Monday', 'Tuesday', etc. +A slightly more complex scheme, where the goal is to have an independent +tape or media set for each weekday, for example from Monday to Friday. +This can be solved by having a separate media pool for each day, so 'Monday', +'Tuesday', etc. Allocation policy: should be 'mon' for the 'Monday' pool, 'tue' for the Tuesday pool and so on. @@ -1020,12 +1021,12 @@ Allocation policy: Retention policy: overwrite -There should be a (or more) tape-backup jobs for each pool on the correspondig -weekday. This scheme is still easily managable with one media set per weekday, +There should be a (or more) tape-backup jobs for each pool on the corresponding +weekday. This scheme is still very manageable with one media set per weekday, which can even be taken off site easily. -Staggered Pools -~~~~~~~~~~~~~~~ +Multiple pools with different policies +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Alternatively, more complex setups are possible with multiple media pools and different allocation and retention policies. @@ -1038,11 +1039,7 @@ Allocation policy: Retention policy: 3 weeks -This creates a new media set each week, and expires them after the 4th -media set. - -Then in addition, there could be a yearly pool that only gets allocated -once a year, but will not be expired (e.g. for long-term archival purposes): +And another pool with yearly allocation that does not expire: Allocation policy: yearly