Re: Mirroring, Striping, Etc.

Troy Cefaratti ( )
Tue, 03 Feb 1998 14:22:52 -0500

At 02:27 PM 2/2/98 -0800, you wrote:
>Can someone offer some information regarding performance
>improvements/degradation caused by drive mirroring and striping on NT 4?
>We recently added a second drive to our mail server and set it up as a
>mirror drive. Since then, it seems to be slower in responding when sending
>mail. It may just be perception, since I am paying more attention to the
>machine now.
>We are running a PP150 w/128 MB Ram and 2- 2.1 GB SCSI on an Adaptec 2940.

Mirroring two drives will be slower due to the fact that the machine writes
EVERYTHING to both drives. The advantages of mirroring are for data
recovery should one drive fail.

Striping the drives will give you increased speed because a file can be
spanned accrossed all of the drives in strip set. (if you have a 3MB file,
and a stripe set of 3 drives, it will write 1MB of the file to each drive).

I currently have a strip set under winNT 4.0 consisting of three 5.1GB
Maxtor IDE drives. This gives me a 15GB drive partition, and even though
they are IDE drives (not even UltraDMA) it is surprisingly fast at data

Striping does have its downside though. If one drive fails, you will lose
the data on ALL the drives.

It is because of this that striping WITH parity is a better choice for
mission critical applications. And maybe even a "hot spare" drive in the

Troy Cefaratti
Cefaratti Network Solutions
StarBase One Communications
425-A Superior Building
815 superior Avenue (216) 619-1500
Cleveland, Ohio 44114