Re: CPU 0.1% IOWAIT 99% for decisonnal queries

Hello Gustavo,

Your question seems to say that you suspect a disk issue, and a few hours later, Simon told me "Sounds like your disks/layout/something is pretty sick".
To be clear in my own mind about it, I've just copyed (time cp) the "aggregate" table files (4 Gb) from one disk to an another one: it takes 22 mn !(3 Mb/s).
That seems to demonstrate that Postgres is not the cause of this issue.
I've just untrusted to my system engineer the analysis of my disks...

In case I would have to change my disks, do you have any performance figures related to the types you mentionned (reiserfs vs ext3) ?
I don't use RAID since the security is not a concern.

Thank a lot for your help !

Patrick

Hi Patrick,

How is configured your disk array? Do you have a Perc 4?

Tip: Use reiserfs instead ext3, raid 0+1 and deadline I/O scheduler in kernel linux 2.6