Обсуждение: RAID0 vs RAID1 vs RAID?

Hello all.

I have a production postgresql 7.4.5 database on a HP Proliant ML330 G3
server, OS: SUSE SLES8, two SCSI disks in RAID1.

I just cloned the same database (same data) on another server. It's
another HP Proliant ML330 G3 with SUSE SLES8 on but it has the latest
7.4.x release (7.4.8) and the disks are two ATA disks in RAID0.

The same queries run 6 times faster on the second server!

Is it possible that RAID0 is 6 times faster than RAID1? Since RAID0 has
no fault tolerance, what is the RAID configuration that gives maximum
performance and reliability? RAID10?

Thank you. Kind regards,

--
Cris Carampa (cris119@operamail.com)
"E` evidente che siamo di fronte allo sfruttamento opportunistico
  di quella quota di astensioni fatalmente derivanti da disinteresse
  o indifferenza." (Gustavo Zagrebelsky)

Cris Carampa wrote:
> Is it possible that RAID0 is 6 times faster than RAID1? Since RAID0 has
> no fault tolerance, what is the RAID configuration that gives maximum
> performance and reliability? RAID10?

Short (same old) answer: it depends.
It's no surprise that RAID0 outperforms RAID1 expecially in the write
performance.
Fault tolerance is has its own overhead. A smart RAID controller takes
advantage in read operations in both cases, but it's definitely
different in write operations.
You have to check whether your db configuration or application dml
statements affect the performance tests (eg. they are the most frequent
operations).

Bye

--
Rodolfo Baselli
Wolters Kluver Italia Professionale
"I'm no supervising technician, I'm a technical supervisor." - Homer Simpson