I am new to PostgreSQL. I'm setting up a new PostgreSQL server to handle large amounts of performance data collected from our batch processing pools, we're currently handling about 8M rows of new data per day stored into tables with about 6B rows total. The server I have has eight cores and 32GB memory, with 9TB of fibre channel storage. I'm using LVM2 for disk allocation and XFS so the volume sizes can grow as needed. The default installation of PostgreSQL 8.4 uses one disk for both data and logs. Normally you would allocate multiple data disks and a transaction log disk. I have not seen anywhere in the documentation or configuration files where you can specify extra data disks or separate log disks.