Raid - Sata vs. SCSI

[amcdonald]

How big would the performance gap be for these sytems:

raid 5:
3 80gb 7200 sata drives

raid 5:
3 10k 36gb SCSI u320 drives

This would be for an exchange server, less than 100 users.
The scsi would be way faster, but is it even necessary?

 

[newParadigm]

The gap would be HUGE, as demonstarted between the dif between say a single raptor drive (10k SATA) and an equivalently sized 7200 SATA Drive. Is it worth the money, that i can't say.

 

[amcdonald]

Originally posted by: newParadime
The gap would be HUGE, as demonstarted between the dif between say a single raptor drive (10k SATA) and an equivalently sized 7200 SATA Drive. Is it worth the money, that i can't say.

Yea, i realize the performance gap, so I guess what I'm really asking is what I need to ensure the exchange server performs well.

 

[Markfw]

Yes, you need the SCSI for that to perform well with 100 users. Make sure you get a good caching controller. And 15k drives would be much better.

 

[jose]

In a multi-user environment scsi is King.. Ide/sata is fine for single users, also fine for multi-user where speed is not important & size is...

Also scsi drives never seem to break, I have 2g, 4.5g & 9gigs just sitting around, they never break..

Regards,
Jose

 

[carpenter]

I'm reading your reply amc. You said you realise the performance gap, but need the server to perform well. Think you answered your own question.

The best you is inside of you. -Mr. Miagy

 

[sharkeeper]

4GB RAM for improved database performance will help a lot.

Also, forget about RAID5 unless you plan to have your database, paging file, and log files on dedicated physical drives.

Many make the mistake of creating a single RAID5 volume and partitioning it with a boot drive and a data drive. That most definitely is NOT the way to go unless you like the hourglass.

Cheers!

 

[amcdonald]

Originally posted by: jose
In a multi-user environment scsi is King.. Ide/sata is fine for single users, also fine for multi-user where speed is not important & size is...

Also scsi drives never seem to break, I have 2g, 4.5g & 9gigs just sitting around, they never break..

Regards,
Jose

I've got another raid5 array here, and it's worked for almost 4 years without incident. (scsi 10k cheetahs)

I'll go scsi u320 15k then.
I just wanted to make sure it was a good investment before I drop another $1k into the server.
Thanks guys.

 

[amcdonald]

Originally posted by: sharkeeper
4GB RAM for improved database performance will help a lot.

Also, forget about RAID5 unless you plan to have your database, paging file, and log files on dedicated physical drives.

Many make the mistake of creating a single RAID5 volume and partitioning it with a boot drive and a data drive. That most definitely is NOT the way to go unless you like the hourglass.

Cheers!

Should I be planning to use more than a gig of ram?

I know to keep the array independant of the boot drive, But I've seen it done wrong so thanks for the warning.

 

[sharkeeper]

What version of exchsrvr are you planning on using?

I've seen 2003 servers use 1GB+ easy with just 20 users.

Are they going to be predominately in the office using Outlook or will a lot of users take advantage of OWA on the road?

These kinds of things are important in planning as an improperly optimised exchange server is often the cause of complaints of slow performance which gets worse as information store size increases.

Cheers!

 

[jose]

sharkeeper,

Just curious, how would you create a raid5 volumn running Linux w/ a Database. ie Dell poweredge w/ 6 - 15k 36g drives.

The customers need a hot spare & want both the OS & Database to benefit from raid5. Can't have the system down 1-2 days to redo the install.

Regards,
Jose

 

[amcdonald]

Originally posted by: sharkeeper
What version of exchsrvr are you planning on using?

I've seen 2003 servers use 1GB+ easy with just 20 users.

Are they going to be predominately in the office using Outlook or will a lot of users take advantage of OWA on the road?

These kinds of things are important in planning as an improperly optimised exchange server is often the cause of complaints of slow performance which gets worse as information store size increases.

Cheers!

It'll be 2003.
No OWA, all internal.

 

[sharkeeper]

With six drives, one would use RAID1 for OS and RAID5 for data, one drive hot spare. Not the ideal set up performance-wise, but this is the minimum config to give best match of OS performance and availability. With Dell, this would be a PERC4 HBA. Upgrade to 256MB cache and BBU is a must.

If you're not using OWA and 2003, I'd baseline 2GB RAM minimum and a good caching HBA such as Intel SRCU42X or LSi MR320-2X.

SATA drives will work if you use a decent controller such as 3Ware 9xxx series or LSi MR STATA 150-6. The XORPU on the 320-2X/SRCU42X is much more powerful than the SATA solution but it all boils down to the buck I suppose...

Cheers!