Hi all,
my question was about performance tuning for large memory/CPU
consuming computing. There are received suggestions:
1) read the 'System Tuning and Performance Management Guide' (on-line docs)
2) change the following params and rebuild kernel:
dfldsiz maxdsiz (default/max data segment size)
dflssiz maxssiz (default/max stack segment size)
3) change entries in /etc/sysconfigtab and reboot (suggestion follows)
>>>>>>>>>>>
I run an 8400 (6CPU, 2Gb RAM, DU 3.2c) as well for exactly the same purpose.
I have changed various parameters for virtual memory as well as the file
system buffer sizes. Here is my /etc/sysconfigtab file:
#
vm:
vm-page-free-target = 8000
vm-page-free-min = 5000
vm-page-free-reserved = 500
vm-page-free-optimal = 3000
vm-maxvas = 2147483648
ubc-maxpercent = 10
ubc-minpercent = 5
ubc-borrowpercent =5
vm-ubcseqstartpercent = 8
proc:
max-per-proc-address-space = 2147483648
per-proc-address-space = 2147483648
max-per-proc-data-size = 2147483648
The vm entries try to keep enough free physical memory to stop periods when
the machine runs out of memory and and has to do lots of paging and swapping
to reclaim space when its all a bit late. This really kills interactive
response hence the changes. The ubc settings stop the filesystem from taking
too much memory for the same reason, the defaults are O.K. for small machines
but I do not intend to allocate 400Mb to filesystem buffer space. The proc
entries are the ones to do with process size. The max-per-proc-address-space
one is the virtual size. By default with DIGITAL UNIX this is 1Gb, my setting
puts this upto 2Gb. The per-proc-address-space one is the default virtual
size which I have set to 2Gb as well as the limit command in the tcsh shell
dosen't let you alter the virtual address size up from the default value!
<<<<<<<<<<<
Thank you very much for all replies!
Best regards,
Lubos
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Lubos Kejzlar
System and Network Specialist
Laboratory for Computer Science Tel.: +42-19 2171210
University of West Bohemia +42-19 7221530
Americka 42, 30614 Pilsen Fax: +42-19 7222435
Czech Republic E-mail: kejzlar_at_zcu.cz
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Received on Mon Mar 04 1996 - 10:42:10 NZDT