Hardware

Ask something
Discussion Locked

*Disk Administration*

0 helpful
8 replies

by engr

Closed to new repliesThis discussion is closed. It stays readable, but it takes no new replies.

I have two hardware identical Digital servers (Digital Server 5000 model) running under Winnt4.0

Each contains 7 scsi slots for Hard disks and they are occupied as follows: 4(9.1GB) disks, 2(4.3GB) and 1 free slot in each.

When accessing thedisk administrator under Administrative tools for any server, you observe only two disks as follows:Disk0 4094MB, Disk1 26034MB and CD ROM.

It seems that disk0 represents one of the 4.3GB hard disks. But disk1 is a combination of 3 (9.1GB) disks...
1. Is this true..? if it is, how about the remainig two hard disks that are not utilized 1(4.3) and 1(9.1)..? how can i activate them
2. how can i combine hard disks so that they appear as one disk for the user..? is it possible to recombinethem as well..?
3. Lately one of the servers is giving a warning message during startup that the scsi drive (Chn 0 Tgt 3)is dead. I noticed that a yellow light for a 9.1GB HD is on, which means the problem in that drive i think. I thought i will lose some space or data, but no data seems lost and disks space in the disk administrator not effected. can you explain please..?
4.How to recover from a dead scsi drive..? should i replace?
5. If i swap the places of 2 hard disks residing on the same server (put each one in the slot of the other) what impact does this action have on the system?
if you can help or you know know online recources that can help me understand such matters please mention

thanks in advacne

8 replies

by jimbb

I'm not really a digital expert, but this looks like nothing unusual. It seems you have a RAID controller, or two, and two RAID sets. The first one with mirroring, probably meant to be used for the OS only, and the second one with Data Guarding, probably meant for user data or so.

The goal of a RAID controller and RAID disks is to provide fault tolerance. And you've benefited from that: on dead disk, your controller fixes the problem, the OS doesn't notice it.

So...
1. RAID combines individual disks and presents them to your OS as one. The OS doesn't care which disks, how big, how many. Your controller handles that, including the built-in fault tolerance.
2. Wouldn't advice you to do so. Leave the NT OS on its "own" mirrored disk, separated from the rest.
3. Your RAID controller takes care of fooling your OS, and pretending there is no problem. However, (4.) if the disk is dead, it needs replacement. No other thing to do, your RAID controller will take care of the rebuilding on the data on it.
5. Mmm. Difficult to answer, since I don't know the details of your RAID controller. Some can handle it, some can't. Wouldn't do it.

Try this for the different RAID levels: : http://www.twincom.com/raid.html
I think you have RAID1 (the two 4.3 GB disks) and RAID5 (the other set).

Jim

by engr

Thanks Jim for your valuable answer...
But.. Does Disk Administrator in WinNT 4.0 give you any of the functionality available in the Win2000 disk administrator..?, i mean like reactivating a missing disk or breaking a mirrord volume..? are there any other utilities that i can use for that..?

by don christner

Before you do anything, you MUST understand EXACTLY how your 6 physical drives are being used by NT. I agree with Jim that 2 of the drives are probably mirrored for your boot partition and the other 4 are probably set up as RAID5. Until you understand exactly which drive goes where, do not attempt any changes. The fact that you are getting an error condition means that you are running with short on time to get it fixed.

I would get on the MS TechNet site and read all I could about RAID setups. Reboot and write down the drive info as the SCSI reports and you see which drive spins up. If the failed drive is one of the mirrored drives, you will need to break the mirror in order to replace the drive. If the failed drive is the first drive in the mirror, you will need to edit boot.ini so that it will boot off of the good drive. Then it will automatically rebuild the drive when you establish the mirror. If it's one of the RAID5 drives, from the data on the other drives it can rebuildthe missing data. Again, see MS TechNet for details on the procedures.

Go slow and understand what you are doing and you'll be OK.

Don

by fenaikh

Hi
your system maybe using integrated Hot-Swap drives, dual redundant backplane capabilities, RAID

go to this site to read about RAID.

www.pcguide.com

and search for raid

Good luck.

Mohamed

This discussion is closed to new replies.