Hans-Ole Kaae, ScanConsult wrote:

> We have quite some defragmentation on one of the 2 disks in the
> System Volume (not LDEV 1).
>
> Trying to avoid a reload, I did the following:
>
> 1) Located all files on this LDEV, generating a storelist.

I am not sure how you came up with a list of files
that *only* have their extents on (I assume) LDEV 2.
I think that might be the wrong assumption here, you
might have selected files that have their file labels
on LDEV2, but not necessarily (all of) their extents.

[snip]

> I did a :DISCFREE A before and after the operation - but while I
> expected MPE to 'fill in the gaps' yielding a less fragmented volume
> after the operation, this was certainly not the case.
>
> One explanation can be that MPE is so intelligent (Yes, I know and
> agree it is intelligent!) that it recognizes the file (assuming the directory
> entry is just marked for deletion), checks and finds that the file is still
> intact on disk and then compares the contents of the diskfile with the
> tapefile. Finding that the 'purged' file on disk is ok, MPE just clears the
> 'purgeflag' in the directory.

You are assuming too much intelligence here.
Basically what RESTORE does is :

1) get file label information from tape
2) build file in the NEW domain (no directory entry)
3) restore all the contents for this file.
4) only if all content was read successfully
    (imagine hitting media read errors) RESTORE will
    purge the file with the same name in the directory,
    then save the restored NEW file into the permanent
    domain.

> BTW: I asume that we have no Condense utilities available in MPE
> anymore? (Sorry, purchasing more utilities is not an option this time).

have a look at VOLUTIL : CONTIGVOL command. it 'condenses' free disk
space areas into larger contiguous chunks. If used with the UNRESTRICTED
option it will even move extents that are in use to another member
of the same volumeset to achieve larger chunks.

In your situation with a 2 member volumeset, probably an INSTALL
(CSLT); RESTORE ;;DIRECTORY and a RESTORE @[log in to unmask]@;OLD;KEEP with
;VOLCLASS=DISC option is the fastest way to defragmented disk
space. (IIRC, volclass=disc will spread extents evenly between the
members overriding existing volume restrictions).

HTH,
Goetz

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