>>>>> "SH" == Stephen Howie <[EMAIL PROTECTED]> writes:

SH> Richard-
SH> That was very helpfull Thanks!
SH> I still would like some guidance on tunning FreeBSD (shmmax and shmmaxpgs).
SH> Do I need to even touch these settings?

Here's what I use on FreeBSD 4.7/4.8.  The kernel settings don't hurt
anything being too large for the SHM values, since they are limits,
not anything pre-allocated (from my understanding).  These settings
allow for up to 100,000 shared buffers (I currently only use 30,000

options         SYSVMSG                 #SYSV-style message queues

# only purpose of this box is to run PostgreSQL, which needs tons of shared
# memory, and some semaphores.
# Postgres allocates buffers in 8k chunks, so tell Postgres to use about
# 150 fewer than SHMMAXPGS/2 buffers to leave some room for other Postgres
# shared memory needs.
options         SYSVSHM                 #SYSV-style shared memory
# Maximum number of shared memory pages system wide.
options         SHMALL=262144
# Maximum size, in pages (4k), of a single System V shared memory region.
options         SHMMAXPGS=262144

# only need semaphores for PostgreSQL
options         SYSVSEM                 #SYSV-style semaphores
# Maximum number of System V semaphores that can be used on the system at
# one time.
options         SEMMNI=32
# Total number of semaphores system wide
options         SEMMNS=512
# Maximum number of entries in a semaphore map.
options         SEMMAP=256

Also, in /etc/sysctl.conf I put

# need lots of files for database
# tuning for PostgreSQL

Vivek Khera, Ph.D.                Khera Communications, Inc.
Internet: [EMAIL PROTECTED]       Rockville, MD       +1-240-453-8497
AIM: vivekkhera Y!: vivek_khera   http://www.khera.org/~vivek/

---------------------------(end of broadcast)---------------------------
TIP 4: Don't 'kill -9' the postmaster

Reply via email to