To: alpha-osf-managers
Hi all,
I'm trying to do some memory tuning on my system and have a couple of
questions for the experts....( I apologize in advance for the length....)
I just downloaded the sys_check program from
ftp://ftp.digital.com/pub/DEC/IAS/sys_check/ and I'm looking for comments
on it. I ran it and it returned a ton of useful information.
This sys_check program made the following suggestions,
decrease vm-ubcseqstartpercent from 50 to 30
increase vm-mapentries from 400 to 16384
increase vm-vpagemax from 16384 to 65536
increase maxusers from 128 to at least 512
Detailed information about the system is included later...
vm-mapentries, what are they used for ? The system admin guide
states: map entry describes one unique disjoint of a virtual address space.
Translation ? What ramifications are there for raising it ?
vm-vpagemax, Again an english translation please... Also suggested
amount to raise seem to be allot, but since I'm running Oracle with the
Multi-threaded-server (single connection to the database for many users) it
makes sense to raise it. What are the ramifications ?
maxusers, This system will eventually run 1000+ connections, what
should this value be set to ? I have asked digital and basically got a
quote from the sys admin guide.
ubc-maxpercent, since I'm running Oracle and the database already
caches allot of data in the SGA does it make sense to lower this value ?
This system's primary duty is Oracle. I have seen vpf_ubcpages go upto
500mb (all available memory) on this system and it seem to me like a the
system is caching the database twice, once in Oracle and once in UBC. Is
that assumption correct ?
About the system:
Digital UNIX V4.0D Worksystem Software (Rev. 875)
System Type: DEC4100
Number of CPUs: 1 Type: EV56 Speed: 465 Mhz Cache: 4.0 MB Memory size: 1024
MB
Oracle recommend changes that I have made:
vm:
vm-maxvas = 1073741824
vm-mapentries = 400
new_wire_method = 0
ubc-maxpercent = 50
ipc:
shm-max = 76980000
shm-seg = 32
msg-max = 8192
msg-mnb = 16384
msg-mni = 1024
msg-tql = 4096
sem-aem = 16384
sem-mni = 200
num-of-sems = 200
sem-msl = 200
sem-opm = 200
sem-ume = 200
sem-vmx = 32767
dlm:
dlm_disable_grptx = 0
proc:
max-proc-per-user = 1024
max-threads-per-user = 1024
max-per-proc-data-size = 1073741824
max-per-proc-address-space = 1073741824
and in the kernel, maxusers = 128
Application:
Oracle 7.3.4
Clients connect to system via rpc calls, client process on the system then
connect to database via sql*net.
Thanks,
Mark Greenhalgh
IDX Systems Corporation
mark_greenhalgh_at_idx.com
Received on Wed Mar 18 1998 - 23:45:03 NZST