Combining hard drives

[kelly]

Someone told me that they have 2 physical hard drives that they combined to one logical drive. They then took that logical drive and partitioned it into 2 logical drives.

So - they have something like 2 ea, 80 GB physical dirves to start and ended with 2 logical drives: one being 20 GB, the other being 140 GB.

I've never heard of doing this? Is this really possible?

- tony

[dbarrow]

could be done using Raid. Create using 2x80=160 array, partition that out any way you want.

[kelly]

Yes - I have the machine in here now. I think one of the hard drives is drying. Here's the config:
IDE 1: CD-RW & CD/DVD ROM
IDE 2: Zip drive
IDE 3: 80 GB HD
IDE 4: 80 GB HD

When you fire this up - BIOS says 2+0 stripe
Device manager reports Promise 2+0 stripe/RAID0 SCSI Disk Drive
C drive is 7.81 GB, D drive is 145 GB

Problem is one of the hard drives is making mechanical noises like it's failing and desktop comes up missing icons and it shuts down/restarts after a few minutes.

[dbarrow]

Array could be corrupted.
Noise, clicking, is a sure sign drive is about to go south.
... the sound of the read/write arm sticking and not jumping to the sector...

I would....
Try and figure out which drive it is, (you can feel it)
Place that drive in the freezer for an hour,
Put back in machine
Use Acronis boot media cd to boot the machine and see if it can successfully read the partitions.
Quickly image everything off to a network machine.

The problem with Raid0 is that it is not redundant.
When the drive fails, the whole array and everything on it are gone for good.
The freezer trick has been known to work as expansion and thickening of lubrication sometimes gets the drive arm to work just long enough to pull a backup image off it.

Replace the drive and restore.
I would NOT return the machine to Raid0 again.
I have sworn off Raid0 (except on this machine which I am too lazy to break down and convert) as I have run into too many complications and incompatibility with backup software (no matter if they swear they support Raid0 or not). Performance difference appears negligible anyway.
You may have to use the XP cd and Repair Console to "fix boot", "fix MBR" once you have done the restore as disk configuration will be different.

[Dan18960]

This sounds like what some rocket scientist did on a client's server.

One - YES you can "span" drives - but once done you are HISTORY if EITHER DIES! You lose data, programs, whatever - everything is sauce!

Two - YES you can split the span - again you are going to lose EVERYTHING if one of the drives dies! Remember you are talking about LOGICAL drives here NOT physical. So because you are doing a logical span and split partition - you are ONLY thinking you have control over the data saving location. The system has selected how it wants to devy up the segments and is only providing you with a "designated" logical location.

For instance - in a logical span the drives "may" show you as saving a file on the drive when it actually is saving it in segments on both drives. In splitting the span partitions you are "assuming" that the one partition is on the same drive when in fact the SPACE may span the drives also! You don't have control of the software span of the drives.

Now on the fact that drives are CHEAPER than they use to be - this is really something I would NEVER do with a system. Get an 80g drive for the sys files and get a 300g for the data/video/pictures/music or whatever.

[kelly]

That's pretty much what I plan to do. I've already separated the drives from the enclosure and determined which drive is making noise. What I'll do different from your suggestion is to connect it to my XP machine to make the Acronis image.
thanks
- tony

[kelly]

Too late. The drive seems to be gone. Put it in my machine to image it and Acronis says no data on it. Then put it back in original machine and that machine no longer boots. RAID info says it's damaged or disconnected. I can hear it clicking.

Now - I put the good drive in my machine to see if I could pull files off of it. Windows doesn't recognize the file system.

I haven't researched RAID methods, but I wonder how it does what it does. What does it do to the file sturcture. Should I be able to pull files off the remaining good drive?

- tony

[Dan18960]

Tony,

I guess you didn't understand my post - spanning does NOT designate a drive - it designates a SPAN segment. Bits are spread across drives joined by the spanning. There are NO FILES - there is ONLY bits. The file system was trashed the minute you separated the drives and you attempted to "read" the file system from your hard drive.

Doug explained that you should have placed the "clicking" drive in the freezer and then booted from the ORIGINAL machine. The drives would have recognized their span, their segments, AND JUST MAYBE you could have done an image of the system. On the very slimmest chance YOU could have pulled at least the data off to an external drive.

Another reason for backup here. Hopefully the client has a backup of some sort. If not send BOTH drives to Ontrack or Drive Savers and make sure you tell them that there was a span created by them.

[dbarrow]

Can't do that.... it was a Raid0 array. Data is on both drives and they have to be an array to be seen. Individually, you can't see a file system on them.

Freeze the bad drive.
Put it back in the original machine on the original bus connection along with the other one and try to boot from the Acronis cd. (sometimes a gentle tap with a wooden hammer can jar it into action).
IF... Acronis can see partitions, try to image from the cd to a network machine immediately before it warms up.

If not... try repeated attempts to boot. Sometimes it takes a few tries.