topic Re: indexf.sys question in Operating System - OpenVMS

indexf.sys question

Scotty HD — Sat, 02 Oct 2010 15:22:23 GMT

good morning,

i understand, indexf.sys file holds the file header of files on disk.
one slot for every file on disk.

if i have only few files on my disk then,
indexf.sys holds on to empty slots
or
indexf.sys releases the free slots back to the system?

once indexf.sys file is created on disk, can its size shrink due to any
operation?

i hear DFU can be used to compress directory, is there any tool to compress
indexf.sys?

Scotty

Re: indexf.sys question

Hein van den Heuvel — Sat, 02 Oct 2010 15:35:09 GMT

No you can not trim INDEXF.SYS. Not officially.

>> i understand, indexf.sys file holds the file header of files on disk.
one slot for every file on disk.

Correct. At least one. Could be more due to fragmentation and/or excessive ACL's.

Best/official way to do this is INIT an other disk with the desired attirbutes : /HEAD=/MAX= ...
Next BACK/NOINIT/IMAGE ...

Or roll out, init, roll back.

But is this really such a big deal?

How much over-allocated is it in your case?

Good luck,
Hein

Re: indexf.sys question

Hein van den Heuvel — Sat, 02 Oct 2010 15:46:18 GMT

Actually... DFU ( 3.2 ) _does_ have a command to truncate INDEXF.SYS, for an unmounted disk.

Hein

DFU> HELP INDEXF
:
"The INDEXF command is used to analyze ,defragment ,truncate or extend the INDEXF.SYS file.
The analyze option reports the current fragmentation state, whereas the defragment and extend option allows defragmentation or pre-extending of INDEXF.SYS. Truncate is an option which trims down INDEXF.SYS to the end-of-file size.
To perform a defragment truncate or extend operation the disk must be completely dismounted.
NOTE: defragment truncate and extend require VOLPRO privilege.
: defragment truncate and extend can not be done on the system disk.

Re: indexf.sys question

Robert Gezelter — Sat, 02 Oct 2010 22:04:59 GMT

Scotty,

I am in wholehearted agreement with Hein. Each file on the disk has AT LEAST ONE header. Depending on how many extents a file has, it can have quite a few headers. This is particularly true for files that are routinely appended to (e.g., transaction logs). The number of headers can be seen using the DUMP/HEADER command. To be precise, I recommend DUMP/HEADER/BLOCK=(START:0,END:0) or DUMP/HEADER/BLOCK=COUNT:0.

I generally recommend against trimming INDEX.SYS. There are limits to extending INDEXF.SYS, and I have seen far too many cases where extends were limited by fragmentation, the header for INDEXF.SYS itself can become filled, which is a far more serious problem to deal with. With today's mass storage capacities, INDEXF.SYS is generally not a problem.

- Bob Gezelter, http://www.rlgsc.com

Re: indexf.sys question

Scotty HD — Tue, 16 Nov 2010 13:05:25 GMT

thanks everyone for help

Scotty