RAID 5 recommendation

[dlochart]

When I was reading the multiple server install document in the section where it was giving system requirements I saw a note that said:

On systems with more than 100 accounts RAID 5 is not recommended.

Why is that a recommendation?

[plan9]

Disk writes are slower with RAID 5 as a result of all the parity checking.

[ECB]

In that case, what is the recommended RAID or disk setup for a server hosting more than 100 users?

[phoenix]

Originally Posted by ECB

In that case, what is the recommended RAID or disk setup for a server hosting more than 100 users?

You should use RAID10.

[Chewie71]

Here we do our STORE, INDEX, and DB on RAID10. BACKUP and HSM are on RAID5.

Matt

[uxbod]

Performance Tuning Guidelines for Large Deployments - Zimbra :: Wiki
Ajcody notes on disk subsystems

[3RiversTechAdmin]

Originally Posted by phoenix

You should use RAID10.

What is your opinion of RAID50 and a decent controller w/ battery backed write cache?

Also what is your option regarding filesystems? I have seen much better zimbra performance on reiserfs than ext3 with no problems.

[uxbod]

reiser I would not use IMHO ... stay mainstream on ext3 and optimize. So many factors are involved we would need to understand your full requirement first.

[3RiversTechAdmin]

Originally Posted by uxbod

reiser I would not use IMHO ... stay mainstream on ext3 and optimize. So many factors are involved we would need to understand your full requirement first.

<rant>
I think that is a silly reaction. riserfs3 has been mainstream for a very long time. We use riserfs3 for all of our servers and have for many years, it has been far more solid than ext3 with better performance. People who had riserfs3 problems are thinking back to the early releases with the 2.4 kernel.

If you have technical reasons, then by all means explain. But what you said sounds like the typical anti-riserfs3 FUD.
<rant />

[bdial]

people are rightfully skeptical about the future of reiser given the creator is locked up and the company mainly behind it's development disappeared. however, it's still being actively developed afaik.