Use of RAM
2007-12-25 11:54:00
Thanks for your feedback.
I have learned some useful info and found a useful tool to help out.
Memtool was recommended by most of the replies. I have installed this &
started to get a feel for what it offers. Certainly more than I started
with.
John DiMarco also pointed me at an article by Adrian Cockroft worth a
look :
http://www.sunworld.com/swol-03-1998/swol-03-perf.html
This article references a white paper on the Solaris Memory System
which includes a discussion of memtool as well as a discussion on
memory architecture & capacity analysis.
I have also been able to look at the course notes for Solaris
Performance Tuning by SunSoft. This has a LOT of good stuff in it. If
you want a solid overview, this course seems to be well worth looking
at.
System accounting / ulimit are good management adjuncts.
Thanks to :
John DiMarco <jdd@cs.toronto.edu>
Bryan Blackburn <blb@rmi.net>
"Rose, Robert" <Robert.Rose@ag.gov.au>
Ed Finch <efinch@eos.EAST.HITC.COM>
Regards,
Steve
--
===================================================
Steve Franks
National Australia Bank, Midrange Services
1/216 Victoria Pde ph : +61 3 9208 5794
E Melbourne, Victoria fax : +61 3 9208 5023
Australia 3150 mailto:scf@nabaus.com.au
===================================================
attached mail follows:
Hello all,
I need to establish the use of Sun memory at a level of detail that is a
little more granular than normal. I want to be able to understand the
behaviour of a memory hog and it's impact on a system. Sure I can look
at vmstat (sr / po) & see that it's a killer but dropping in more RAM
seems to me to be a big stick approach & doesn't help me to look for
opportunities to help the process out (or justify it's removal).
I want to be able to establish what parts of memory are being used by
the kernel and what for (eg, buffers, static table, dynamic tables &
work areas like the stack ..), what percentage is being used by shared
objects, what percentage by misc thus telling me what is available for
processes.
vmstat, sar, swap etc tell me a little of the story but not all of it.
Are there any tools that would allow me to profile physical memory in a
simple way?
I know I have tools like pmap & ldd but quite frankly, I will be here
until the new century trying to add up the numbers & come to some
sensible understanding & they don't help with the kernel in any case
(particularly the dynamic components).
I also need a better understanding of how processes and the kernel use
memory & shared objects.
Cockroft has a nice overview in his book but he admits that it is vastly
simplified. Answerbooks, SM FAQ & archive searches have produced
nothing consequential (usually, items are large scale overviews or
overly simplistic descriptions).
I am not a code-cutter so there may be some goodies in that realm that I
am missing. I have found some refs to this sort of stuff in a coding
context but they all miss the framework of understanding, the model, I
am after.
I have a sneaking suspicion that what I am after would fill a book
but...
Can anyone point me to some useful docs and / or tools that I can use on
my SS20 / UI systems running S2.5.1?
Thanks,
Steve
--
===================================================
Steve Franks
National Australia Bank, Midrange Services
1/216 Victoria Pde ph : +61 3 9208 5794
E Melbourne, Victoria fax : +61 3 9208 5023
Australia 3150 mailto:scf@nabaus.com.au
===================================================
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