Will shared_buffers crash a server

Hei:

We have PostgreSQL 8.3 running on Debian Linux server. We built an applicantion using PHP programming language and Postgres database. There are appoximatly 150 users using the software constantly. We had some performance degration before and after some studies we figured out we will need to tune PostgreSQL configurations.

We have 10GB memory and we tuned PostgreSQL as follow:

- max_connection = 100

- effective_cache_size = 5GB

- shared_buffer = 2GB

- wal_buffer = 30MB

- work_mem = 50MB

However we suffered 2 times server crashes after tunning the configuration. Does anyone have any idea how this can happen?

BR

Kevin Wang