On Mar 13, 2006, at 6:00 AM, Remco Post wrote:

Hi all,

I'm a bit confused, so I was hoping maybe the list could help.

When I read the help on def stg/upd stg for the Maxsi parameter it
mentionses
two things:

1- It's the size of the physical file (aggregate)
2- it's the size of the file before compression if compression is
used.

Now during backup I can inmagine that 2 is being used, but during
migration/backup stg/whatever I can only inmagine TSM using the
size of the
aggregate or the size of the file on the filesystem, but not both.
So which is
it? Is the use of the size of the file before compresion the old way
(pre-aggregate) way of doing things? Is the manual wrong? Is the
help wrong?

(and yes I've read the quickfacts, and no, they don't make things
any clearer)

Hi, Remco -

I think you picked up the item about compression being a participant
in storage pool operations, from the TSM Concepts redbook.
Unfortunately, that part of the redbook is poorly written, failing to
explain the context of its discussion, leading to confusion.

Compression is a factor only when a file is being backed up, and at
that point the TSM server is evaluating the size reported by the
client in deciding which storage pool the new object (actually, an
Aggregate for B/A; an individual file for HSM and perhaps TDPs) will
land in. Once in TSM server storage, the object is just a clump of
bits: no considerations for compression prevail. Where it will fit
thereafter is a function of Aggregate size (which can shrink during
reclamation operations, most visibly via MOVe Data RECONStruct=Yes).

    Richard Sims