postgresql-8.0.1 performance tuning

Hi @ all,

i'm trying to tune my postgresql-db but i don't know if the values are
right
set.

I use the following environment for the postgres-db:

######### Hardware ############
cpu: 2x P4 3Ghz
ram: 1024MB DDR 266Mhz

partitions:
/dev/sda3 23G 9,6G 13G 44% /
/dev/sda1 11G 156M 9,9G 2% /var
/dev/sdb1 69G 13G 57G 19% /var/lib/pgsql

/dev/sda is in raid 1 (2x 35GB / 10000upm / sca)
/dev/sdb is in raid 10 (4x 35GB / 10000upm / sca)
######### /Hardware ############

######### Config ############
/etc/sysctl.conf:
kernel.shmall = 786432000
kernel.shmmax = 786432000

/etc/fstab:
/dev/sdb1 /var/lib/pgsql reiserfs acl,user_xattr,noatime,data=writeback
1 2

/var/lib/pgsql/data/postgresql.conf
superuser_reserved_connections = 2
shared_buffers = 3000
work_mem = 131072
maintenance_work_mem = 131072
max_stack_depth = 2048
max_fsm_pages = 20000
max_fsm_relations = 1000
max_files_per_process = 1000
vacuum_cost_delay = 10
vacuum_cost_page_hit = 1
vacuum_cost_page_miss = 10
vacuum_cost_page_dirty = 20
vacuum_cost_limit = 200
bgwriter_delay = 200
bgwriter_percent = 1
bgwriter_maxpages = 100
fsync = true
wal_sync_method = fsync
wal_buffers = 64
commit_delay = 0
commit_siblings = 5
checkpoint_segments = 256
checkpoint_timeout = 900
checkpoint_warning = 30
effective_cache_size = 10000
random_page_cost = 4
cpu_tuple_cost = 0.01
cpu_index_tuple_cost = 0.001
cpu_operator_cost = 0.0025
geqo = true
geqo_threshold = 12
geqo_effort = 5
geqo_pool_size = 0
geqo_generations = 0
geqo_selection_bias = 2.0
deadlock_timeout = 1000
max_locks_per_transaction = 64
######### /Config ############

######### Transactions ############
we have about 115-300 transactions/min in about 65 tables.
######### /Transactions ############

I'm really new at using postgres. So i need some experience to set this
parameters in the postgresql- and the system-config. I can't find
standard
calculations for this. :/ The postgresql-documentation doesn't help me
to
set the best values for this.

The database must be high-availble. I configured rsync to sync the
complete
/var/lib/pgsql-directory to my hot-standby. On the hotstandby i will
make the
dumps of the database to improve the performance of the master-db.

In my tests the synchronization works fine. I synchronised the hole
directory
and restarted the database of the hotstandby. While restarting,
postgresql turned
back the old (not archived) wals and the database of my hotstandby was
consistent. Is this solution recommended? Or must i use archived wal's
with
real system-snapshots?

best regards,

Martin Fandel