reclamation settings

[tsmuser10]

Just for own piece of mind on reclamation setting. I 've read some post where people are setting it to as low as 10. I've read that setting it below 50 does not buy u anything. What is the best ? leave at 50 dip down to 30 ?

Just curious

 

[heada]

The lower the setting, the longer it will take as well as the less you will get back from the process. For example, with a setting of 75, you will combine 4 tapes onto 1 (25% full on each, send off 1 and get 4 back) and a setting of 50 you will combine 2 tapes onto 1 (50% full on each, send off 1 and get 2 back). Once you drop below 50% you will get less than 2 tapes back for each tape sent off. For example, if you have it set to 25%(75% full), you will send off 1 1/2 tapes to get back 2 tapes so you have to send off 2 tapes to get back 2 tapes. Since one of those tapes is only 1/2 full, we can say you'd have to send off 3 tapes to get 4 tapes back so that only full tapes are sent off.

I find that the larger the tape (3592, LTO4, etc) the higher the reclamation threshold just because it takes too much time at a lower setting. I keep mine at 80.

-Aaron

 

[THE_WIPET]

What you can do is seperate your datatype
EX: Structure data (DB,Mail,Image etc.) and unstructure data(File,print,web,os) Since structure data tapes get fragemented faster you could keep an really high threshold or not at all. For unstructure data, well you can tune to your env.

Another thing is you have VTL or using file devclass, you can push your reclamation really high for unstructure data ex: 20-30 since is disk base access.

Just to give you an idea.
ONline pool unstructure data reclamation is at 20
ONline pool structure data reclamation is 80-90
Offlline pool unstructure data reclamation is at 50-60
Offfile pool structure data reclamation is 90
SAP = No reclamation

 

[BBB]

What the_wipet suggested is also what I do. Keep different types of data separate. Eg oracle/sybase/sql db backups are in separate pool to normal files. Long term type backups should also be kept in a separate pool.