11-14-2007
Sorry, but i can't tell you "how to improve the performance" because i don't know why the performance is bad - i simply do not know your system!
I take your word that CPU and memory is not an issue (wonder how you came to this conclusion, but anyways) and will concentrate on what else might be the culprit. Possible reasons include (but are in no way limited to):
Maybe your SAN-subsystem has a problem. If it is a ESS look into the errorlog of the system: the SSA-adapters there have batteries supporting the fast-write-cache, these batteries need to be changed from time to time and empty batteries shut down the FW-cache. This could also be watched by dramatically low write-performance together with a normal read-performance.
Maybe you have native SSA-loops, then the problem directly arises with the cache of the adapter. Look in the error-log it should be mentioned there.
Maybe your filesystem has hotspots, get a trace of the filesystem. Use "vmstat -v" to get a first impression or "filemon"/"trcstop" to get a report. A typical trace would look like:
filemon -u -O all -o /tmp/filemon.out ; sleep 10 ; trcstop
If you see in the output that the trace buffers are too small make them bigger by using the -T option:
filemon -u -O all -T 512000 .....
The output is pretty self-explanatory.
If it is an internal disk look into your errorlog for disk failures. Usually this starts with hdisk3-type errors, which are temporary and ends in hdisk4-type errors, which are permanent. The reason is that disks have some spare blocks and bad block relocation takes place first - temporary errors - but once the spare blocks are exhausted damage for the PP can't be prevented - permanent error.
Maybe you are slowing down your filesystem by bad layout - use LVM tools to get map files of all the filesystems and analyze them.
Maybe your system is slow because it is swapping all the time - have a look at the output of "svmon -G" and compare the memory pages "inuse" and "virtual". If "virtual" is much bigger than "inuse" that hints to more memory needed by the running applications than there is. Multiply the number by 4k (size of a memory page) to get a rough estimation of how much more memory you need.
and, and, and .... I could go on for hours with similar considerations, all starting with "maybe". Unless you provide no data nobody can tell you anything about your system.
bakunin
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PMC(1) BSD General Commands Manual PMC(1)
NAME
pmc -- performance-monitoring counter interface for command execution
SYNOPSIS
pmc -h
pmc -C
pmc -c event command [options ...]
DESCRIPTION
pmc is a means of using a processor's performance-monitoring counter (PMC) facility to measure various aspects of a program's execution. It
is meant to be used in a fashion similar to time(1).
The arguments are as follows:
-h Display a list of performance counter events available on the system.
-C Cancel any performance counters that are currently running.
-c event
Count the event specified by event while running the command.
DIAGNOSTICS
PMC support is not compiled into the kernel Performance-monitoring counter support has not been compiled into the kernel. It may be
included using the PERFCTRS option. See options(4) for details.
PMC counters are not supported by CPU Performance-monitoring counters are not available for the CPU.
SEE ALSO
time(1), options(4)
HISTORY
The pmc command first appeared in NetBSD 1.6.
AUTHORS
The pmc command was written by Frank van der Linden <fvdl@wasabisystems.com>. The kernel support for reading performance counters on the
i386 architecture was written by
Jason R. Thorpe <thorpej@zembu.com>.
BUGS
The pmc command currently only supports performance-monitoring counters on the i386 architecture.
BSD
October 24, 2000 BSD