Postgresql is very slow

Hello to list,

We have a CentOS-5 server with postgresql-8.1.8 installed. I am struggling with postgresql performance. Any query say select * from tablename takes 10-15 mins to give the output, and while executing the query system loads goes up like anything. After the query output, system loads starts decresing.

Any query select,insert,update simple or complex behaves in the same way, what i have explained above.

System Specification:

OS :- CentOs 5
Postgresql 8.1.8
RAM :- 1 GB
SWAP 2 GB

Some relevent part(uncommented) of my /var/lib/pgsql/data/postgresql.conf

listen_addresses = 'localhost'
max_connections = 100
shared_buffers = 1000

The one more strange thing is that with the same setting on another server, postgresql is running very smooth. I had run vacum also some times back.

Please help me out and let me know if you need any other information.

Thanks & Regards,

Bijayant Kumar

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