NT 4.0 and disk administrator w/ 9.1 gig hard drives 2

[surfandsand]

I am running NT 4.0 with what I am assuming is h/w raid. Ironically it looks like RAID because there are three drives 9.1 gigs a piece and in disk manager it shows a total of estimated 18 gigs with no fault tolerance. I can not imagine this a a mirrored set or even a raid 0 or 1. So my question is before I go adding another hard drive(for much needed space) can someone tell me why disk manager says what it says.
If this is to vague let me know.

c: 344mb (free space) / 2048mb (capacity)
d: 4705 (free space compressed) / 15268mb (capacity)
total 17316mb
remember there are 3 9.1 gigs hard drives in this machine, no fault tolerance.

 

[wolf2x]

Do you get any messages during bootup? concerning raid?

You may have RAID 5...hardware raid.

For example, we have an old compaq with hardware raid. According to Disk Administrator, it sees a 45 Gig drive which in reality is 6x9.1 harddrives with raid 5.

 

[surfandsand]

I have found out it is RAID 5 but something still puzzles me. In disk administrator, it show no fault tolerance, yet there are three disks showing two logical drives (hence the raid 5 with parity) . All the hard drives are indicated with a green light to show active and runnning well. Also I used the software management CD that came with Compaq and all seemed fine as well.

Do you know why NT disk administrator does not indicate fault tolerance?

 

[wolf2x]

I believe it would only show in Disk Administrator IF it was software raid.

Using hardware raid, it basically "fakes" the operating system into thinking it is only one drive.

 

[Sanjiv123]

We have similar setup. If it is a Compaq, Try using the Disk Array Utility in Control Panel instead of Disk Administrator.

RAID 5 is also called Distributaed Data Guard in this scenario.

You should get a more accurate picture.

 

[OzDog]

Surfandsand,

wolf2x and Sajiv123 are about right. When you use hardware raid, the NT system cannot tell that there is RAID in place. OEM utilities (like Compaq's Array Configuration Utility (ACU)) can be used to view Hardware Fault Tolerance configurations as they interface with the hardware directly (through the HAL) and read the config, but the OS cannot see this. It's meant to be this way.

Disk Administrator is a very basic application and cannot interface in the way that OEM apps can. And NT's software fault tolerance is horrendous. Go the Hardware option whenever possible (in fact - use software only as a last resort).

Regardless of brand, you should be able to look at the configuration at boot time. In most Tier 1 Server manufacturers (Compaq/HP/IBM etc) you usually press a Function key to access it when the message pops up.

If using Compaq, the ACU can be installed later if necessary, and RAID sets can be expanded to include new disks as required, although it takes a lot of time. If the machine/software you have does not include that option, then adding a disk will require a backup/restore.
Cheers,
Sam

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