topic Re: How to see the disk's fragment status or file's fragment in Operating System - OpenVMS

How to see the disk's fragment status or file's fragment

skynet1980 — Mon, 29 May 2006 21:27:30 GMT

Hi,
Is there any command that can see disk's fragment status or file's fragment?

Re: How to see the disk's fragment status or file's fragment

Hein van den Heuvel — Mon, 29 May 2006 21:31:15 GMT

The HP Defrag tool DFO has a free reporting functions.

Personally I would recommend picking up the DFU freeware tool. It is a must have for disk/file management with fragmentation reports and file search based on fragments, and extent-headers and more.

For trivial/simple single file fragmenation analysis just use DUMP/HEADER/BLOCK=COUNT=0

Good luck,
Hein.

Re: How to see the disk's fragment status or file's fragment

Wim Van den Wyngaert — Tue, 30 May 2006 01:04:41 GMT

or use this .com to report it (slowly).

Wim

Re: How to see the disk's fragment status or file's fragment

Robert Gezelter — Tue, 30 May 2006 05:15:17 GMT

skynet1980,

The DUMP/HEADER command will display the file header for an individual file, with complete information about the mapping pointers about which blocks (LBNs) on the disk are used by the file.

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

Re: How to see the disk's fragment status or file's fragment

Hein van den Heuvel — Tue, 30 May 2006 06:52:17 GMT

For your entertainment...
On the DUMP/HEAD, and processing the data.
Here is some more playing with perl:

One liner for 1 file, avoiding 2 temp files:

$ pipe DUMP/HEAD/BLOC=COUNT=0 test.mai | perl -ne "$frag++ if /^\s+Count:/; print ""$frag fragments\n"" if eof"

Script with args globbed from command line:
-------------------------------
while ($file=shift @ARGV) {
$frag = 0;
foreach (`DUMP/HEAD/BLOC=COUNT=0 $file`) {
$frag++ if /^\s+Count:/
}
print "$frag fragments in $file\n";
}

Please note the the wildcard file expansion is done before the script runs. This is often helpful, but actually tricky to avoid. One has to protect the wildcards with strong (') or double-double quotes to stop the help, and later strip those.

Script with args explicitly processed
-------------------------------
while ($files = shift @ARGV) {
# print "--$files\n"
$files =~ s/"|'//g; # strip quotes
while ( $file = glob $files ) {
$frag = 0;
foreach (`DUMP/HEAD/BLOC=COUNT=0 $file`) {
$frag++ if /^\s+Count:/
}
print " $frag fragments in $file\n";
}
}

Sample of ugly quote usage:
perl frags.pl """[...]*.mai""" *.log "'*.tmp'"

Hein.