From: Chris Bryant (cbryant@dollar.com)
Date: Tue Aug 20 2002 - 14:29:32 EDT
Thanks to Corinne Haesaerts, Jesper Frank Nemholt, and alan for their
responses. It seems that the higher the percentange in the Aggregate I/O
perf, the better.
here are their responses:
you are correct.
here's a quote from the man page :
Aggregate I/O perf
The efficiency of the entire file domain. An increase in value indicates
improvement
Corinne Haesaerts
Technology Consultant High Performance Servers
UNIX Ambassador
Compaq Belux, now part of the New HP
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You're right, the lower the worse. After a defragment you should get 100%.
--
Un saludo / Venlig hilsen / Regards
Jesper Frank Nemholt
Unix System Manager
Hewlett-Packard Company
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Do the manual page and AdvFS documentation offer a clue?
I don't know for sure, but I'd guess that a higher
aggregate % is better. I base this on comparing the
results of my domain with yours:
# defragment -vn domain
defragment: Gathering data for domain 'domain'
Current domain data:
Extents: 16782
Files w/extents: 13638
Avg exts per file w/exts: 1.23
Aggregate I/O perf: 97%
Free space fragments: 3123
<100K <1M <10M >10M
Free space: 1% 0% 1% 98%
Fragments: 2924 152 29 18
The underlying issue with defragmentation is having files
that are contiguous; one or no extents depending how they
count. For the files on my domain that have extents, the
number of extents is lower than yours. I also have a higher
aggregate I/O performance percentage. Since fewer extents
are better and guessing that extents and aggregate % track
each other somehow, my result suggests that higher aggregate
% is better.
The defragment manual page may explain the result in enough
detail. The system admin. guide may have a chapter on AdvFS
and AdvFS has its own documentation. Older versions put
this documentation with the AdvFS Utilities on one of the
Associated Product CDROMs. In recent versions it should
be part of the base system documentation.
If you don't have printed documentation, PDF and HTML copies
are on the documentation CDROM.
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Admins,
In running defragemnt -vn on some of my domains I am wanting to know
who to interpet what I am seeing. Aggregate I/O perf is at 66% here in this
example, on another server it was 82% and on another server with another
domain it is 34%. I am thinking that the lower the percentage the worse
performance, am I correct in this thinking? If not, could someone give me
an explination?
TIA,
Chris
town # defragment -vn root_domain
defragment: Gathering data for domain 'root_domain'
Current domain data:
Extents: 3404
Files w/extents: 813
Avg exts per file w/exts: 4.19
Aggregate I/O perf: 66%
Free space fragments: 86
<100K <1M <10M >10M
Free space: 1% 7% 25% 66%
Fragments: 36 33 13 4
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