Due to performance issues (which I wrote about on pg-performance list) we will be upgrading our Redhat AS3.0 box (kernel 2.4) to Redhat AS4 (kernel 2.6) in order to take advantage of the better I/O that the 2.6 kernel offers. (I say upgrading but actually we'll wipe the box and start fresh.)
We are running Postgres 8.0.3.
I had assumed we would have to backup/restore the entire db, but I got to wondering if it would be possible to simply point the new Postgres install to the existing db (the data itself is on a separate drive array) and be back up and running without the time to do the restore.
Is this a relatively simple matter? Or is it too hazardous and tricky to bother with?
If it's possible I'd appreciate a list of what I'd need to save off the old drive, where the os and Postgres program itself lived.
Also: Anything to watch out for with Postgres on 2.6 kernel as opposed to 2.4? Any settings that should be different? We've been advised to try "elevator=deadline". We write pretty much 24 hours a day, and have I/O issues!
-Roger