Multiple Single Drives vs RAID solutions?

Question

Multiple Single Drives vs RAID solutions?

shannonjk

SSCarpal Tunnel

Points: 4286
More actions
June 9, 2009 at 1:48 pm

#201253

Greetings all,
I have been tasked with recommending the best hardware solution for a new blade server dedicated to our SQL Server reporting. I do not know 100% of our budget so I am trying to keep it minimal for the moment until I know my breathing room. My question is, if it comes to constraints, from everything I have read on best practices, especially when it comes to hard drive contention, it would be best to have 4 devices. 1 for the OS and apps, 1 for database files, 1 for temp db, and 1 for transaction log.
My question is 2 fold;
1) Would RAID be vastly improved over single 15k hard drives for this solution and
2) Would this be an ideal configuration, or is it overkill?
Link to my blog http://notyelf.com/

Viewing 7 posts - 1 through 6 (of 6 total)

You must be logged in to reply to this topic. Login to reply

Gail Shaw SSC Guru Points: 1004504 More actions · Answer 1

What RAID gets you that single drives don't is redundancy. With the appropriate RAID level, you could have one or more drives fail and have the server still working. With single drives if a drive fails the system's down.

Gail Shaw
Microsoft Certified Master: SQL Server, MVP, M.Sc (Comp Sci)
SQL In The Wild: Discussions on DB performance with occasional diversions into recoverability

We walk in the dark places no others will enter
We stand on the bridge and no one may pass

GSquared SSC Guru Points: 260824 More actions · Answer 2

I'm assuming you mean something besides kilobytes when you say "15k" on the hard drives, but I'm not sure what. Could be RPM, but I'm not used to that being the critical factor in figuring out how many drives you need and what configuration to use. Capacity is more common.

As far as the number of devices, yeah, that's pretty optimal. But keep in mind that a single RAID array can be configured to have that many "drive letters", without it actually giving you the benefits of separate disks. That many separate RAID-1/10/01 arrays will cost a lot more, but will give you the best redundancy. Depending on your RAID controller(s), it can also give you the best performance.

- Gus "GSquared", RSVP, OODA, MAP, NMVP, FAQ, SAT, SQL, DNA, RNA, UOI, IOU, AM, PM, AD, BC, BCE, USA, UN, CF, ROFL, LOL, ETC
Property of The Thread

"Nobody knows the age of the human race, but everyone agrees it's old enough to know better." - Anon

smallmoney SSCarpal Tunnel Points: 4378 More actions · Answer 3

I think we should get a measure of how many users will be accessing the system and what are the performance requirements?

I don't like using single drive configurations because if one drive dies, then so does your SQL Server.

If you think about it, lets say you have:

1. One drive for C

2. One drive for mdf files

3. One drive for ldf files

4. One drive for tempdb

Then it would take only one drive to fail to prevent users from accessing data. Even if you have tape backup, you will have downtime to restore a drive...which you need to know what is the acceptable downtime (5 9's? :crazy:).

For a low budget

I would have a mirror on C, mirror on mdf drive, mirror for tempdb drive and you may be able to get away with a single drive configuration for the ldf's.

But thats really pushing it I think. I worked in one environment where i was on a budget so I got the database files and log files for one main database on one fast RAID 5 config on an HP MSA50 or 150? (forgot the model name). The other small databases (crystal report, symantec, etc) were on the built in RAID on an HP DL380 and it performed well for the amount of users it was handling.

It's really hard to say I would suggesting finding more about the performance and availability requirements.

smallmoney SSCarpal Tunnel Points: 4378 More actions · Answer 4

I was digging through my photos today after taking some pictures on a beautiful day.

I ended up finding this. This is a picture of my old white board at my old job. It was for a small manufacturing company with a tight budget:

Again I highly recommend using RAID for data redundancy and performance (depending on how its setup).

In addition to the performance of some RAID, tuning the Database has a lot to do with performance too like the use of indexes and maintaining those indexes and etc.

I think you should have a fun project ahead of you 😎

Jacob Luebbers SSCarpal Tunnel Points: 4834 More actions · Answer 5

I like that Peter spans four spindles. Even if one of his arms or legs is unavailable he'll still be at work 😛

shannonjk SSCarpal Tunnel Points: 4286 More actions · Answer 6

Thank you for the ino on this guys that helps greatly!

Link to my blog http://notyelf.com/