Rotation GFS calculation media and mechanical

[viberts]

NB) The term may be not exact because my version is in french. Then i will translate the term in english like i think but my english is limited so please be indulgent

I try to setup a rotation GFS and calculate the number of media in daily, weekly and montly pool. In the manual, there are the formulas follwoing :

daily : media daily -1
Weekly : (media weekly * 7 ) -1
Monthly : (media montly * 29) -5

i don't understand these formulas and the mechanic of the rotation GFS.

1) What's is media daily, weekly and montly to mean
2) How transfert is occur from daily pool to weekly pool and weekly pool to montly pool ? automatically ou manual


Thank for your help and patience

 

[ACiDelic]

There are three different "kinds" of tapes for GFS.

1. Monthly tapes are created once a month.
2. Weekly tapes are created once a week.
3. All other backs are daily tapes.

The naming scheme indicates when the backup was taken and the purpose.

When calculating the quantity of tapes you'll need you have to keep in mind the number of tapes you use to backup your data each day. If you use one tape per backup the forumla is easy. If you use 5 tapes each day the number of tapes you'll need for GFS will go up 5 times.

Tapes are moved between the different media pools automatically by ARCserve. You don't have to manually move any tapes.

 

[viberts]

ok for naming scheme and move the tape.

I have a librairy (10 tape and 1 unit)
I have six gfs rotation scheme (one for each server) associated with six different media pool.

I want a full on tuesday and differential other day on GFS rotation based on 5 day. But i want use the minimum tape so i want append the diff job on the same tape.

So one media for full job at the tuesday and one media for all the differential job for each rotation scheme

It's possible or not ?

 

[ACiDelic]

With six GFS jobs and only a 10 slot library you are going to be importing and exporting tapes very often. If you jobs span tapes then you are going to use even more tapes.

Why 6 GFS jobs? You are only using a single drive library so you can't run jobs simultaneously. All your jobs will run sequentially (one after the other). A single job for all 6 servers should be sufficient, will result in a lot less work on your part and will use less media. Also make the job append instead of overwrite.

If you abosolutely must run 6 different jobs you should look into buying a library with a larger capacity and another drive.

 

[viberts]

Because the gestion (the verification) of the job is more easy with 6 little job than one big.

But the capapcity is ok.

Anyway i think i change my mind and do one job with one pool.

Thank for your advice