Will Performance Improve After Adding a Logical Drive? 2

[JohnBates]

Hi experts,

This isn't specific to IBM Raid but I know someone here can give me an answer.

Configuration: 1 HP Xeon server with 3 SCSI 36 GB drives on a single RAID-5 array.

The operation system, the database (SQL Server), the page file... everything is on the C drive.

I say we can improve performance by configuring a logical drive which would contain SQL Server. I think it is best to separate the o/s from the database.

My IT manager says it would not improve performance because
everything is still on the same physical drives, with the same number of read/write heads as before.

Can someone tell me who is correct and why ?

Thanks!
John

 

[JohnBates]

... and the Operating System is Windows 2000 Server.

 

[rclarke250]

Your manager is correct. The SCSI bus will only push so many bits a second, and the drives can only push data at a set rate, splitting the logical drives does nothing for data on the bus. You would only see an increase in speed by going to fibre channel, or a fast SCSI solution. then splitting the os from the DB. IE. a mirror for the OS, and then a raid 10 for the DB,2 striped arrays, that are mirrored together.

 

[JG5]

You definitely want to separate the OS from the SQL program files, or at least give the log files a dedicated drive - you will absolutely see better performance with a dedicated log file drive (every DBA knows this and Microsoft recommends it). Also, with a memory hog like SQL, a dedicated pagefile will only help matters.

 

[technome]

Agree with the others, using separate partitions on the same array will not add performance. Perhaps there would be a minuscule gain, as the data (SQL) would be more confined to a certain area of the disk, then again the partition for the data would be situated closer to the center of the disk, which would offset the minuscule gain.

With Windows server you should never place everything in one partition. Have a small but adequate partition for the OS and at least one for everything else. If the system screws up the OS partition or a drive letter gets messed up, or a virus gets the system, having the OS on a separate partition makes it easier to manage. Have had raid OS partition get screwed up a couple of times, to the point it was easier to delete and recreate the partition (virus), but NEVER had a secondary data partition go south with it.

Aside from adding another array set to run the SQL on....
Having an automatic daily defrag program run will give you 5% more performance. Defrag programs capable of a boot time defrag once a month will also help SQL.

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