This method has many variations and names. A set of numbered media is used until the end of the cycle. Then the cycle is repeated using media numbered the same as the previous cycle, but incremented by one. The lowest numbered tape from the previous cycle is retired and kept permanently. Thus, one has access to every backup for one cycle, and one backup per cycle before that. This method has the advantage of ensuring even media wear, but requires a schedule to be precalculated. The system is generally too complex to mentally calculate the next media to be used.
I would assume idea behind this is not to keep tapes, but rather data on tapes of course... in that case something like this can be done in combination with pools and schedules... depending on approach you would either: a) use script to manipulate existing backups b) had to use manual recycle for full backups or c) manually relabel incremental tapes
In NW world there is something called backup cycle and components inside that cycle depend on each other. If I would need to implement something like this, I would implement it on disk for backup cycle and then what is left would be migrated to tape. Thus I would avoid need for any tape rotation. Of course, that makes sense in case for general retentions of month or so. If you have year then obviously you will have tape rotation in place as well and can't use disk.
If you really have need to keep certain data permanently then backup is not the solution as no backup media type is certified for retentions that long.
What you is in practice are so called daily backups made on daily basis and kept for smaller retention (eg. 1 month) and then monthly backups made once a month made for longer retention (eg. 7 years). NW keeps idea what tapes to use based od count usage and availability.
ble1
4 Operator
•
14.4K Posts
0
May 12th, 2008 15:00
Ulik1
13 Posts
0
May 12th, 2008 20:00
Incremented media method
This method has many variations and names. A set of numbered media is used until the end of the cycle. Then the cycle is repeated using media numbered the same as the previous cycle, but incremented by one. The lowest numbered tape from the previous cycle is retired and kept permanently. Thus, one has access to every backup for one cycle, and one backup per cycle before that. This method has the advantage of ensuring even media wear, but requires a schedule to be precalculated. The system is generally too complex to mentally calculate the next media to be used.
http://en.wikipedia.org/wiki/Backup_rotation_scheme
ble1
4 Operator
•
14.4K Posts
0
May 13th, 2008 00:00
a) use script to manipulate existing backups
b) had to use manual recycle for full backups or
c) manually relabel incremental tapes
In NW world there is something called backup cycle and components inside that cycle depend on each other. If I would need to implement something like this, I would implement it on disk for backup cycle and then what is left would be migrated to tape. Thus I would avoid need for any tape rotation. Of course, that makes sense in case for general retentions of month or so. If you have year then obviously you will have tape rotation in place as well and can't use disk.
If you really have need to keep certain data permanently then backup is not the solution as no backup media type is certified for retentions that long.
What you is in practice are so called daily backups made on daily basis and kept for smaller retention (eg. 1 month) and then monthly backups made once a month made for longer retention (eg. 7 years). NW keeps idea what tapes to use based od count usage and availability.