Re: Mirroring, Striping, Etc.

Nick Muhlbauer ( nmuhlbauer@home.com )
Tue, 03 Feb 1998 18:30:10 -0600

Possibly the best thing you can do (low Budget wise) is get one of the
new adaptec controller cards.
I'm not real sure which model number it is but it looks something like
AAA-131 and AAA-133 the 133 has 3 independant channels where the 131
has 1.
they both have built in raid functions.
that takes all the load off the NT os that is normally associated with
mirroring/striping.
It makes a Big difference.
I would Not reccommend running NT's "software" disk striping on anything
less than a dual pro 200.
I had a single pro 200 set up with a 2940UW and 2 2gb UW drives striped
and it was slow.
I could get a better xfer rate out of them by creating an extended
volume set rather than the striped set.
Now someone told me something about a problem with the new cards... but
that person is quite the moron. I don't really have any personal
experience with these cards, but I am thinking about getting one...
any Comments/complaints?

Nick Muhlbauer
Elknet Communications

Troy Cefaratti wrote:
>
> 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
> transfers.
>
> 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
> array.
>
> ----------------------------------------------------------------------
> Troy Cefaratti mailto:mnementh@sbase1.com
> Cefaratti Network Solutions http://www.sbase1.com/
> StarBase One Communications mailto:webmaster@sbase1.com
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> 815 superior Avenue (216) 619-1500
> Cleveland, Ohio 44114
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