Sign in with
Sign up | Sign in
Your question
Solved

How to separate 2 physical drives combined into 1 logical drive?

Last response: in Storage
Share
January 21, 2010 1:21:44 AM

I don't know much about hardware so I ordered a custom built computer from ibuypower. I ordered two 500GB hard drives for my desktop thinking I'd be receiving two 500GB hard drives that register independently in Windows, but what I have is one logical drive showing up as 1TB in size. The reason I wanted two was so that I could keep my OS/programs on one and keep my data on another, because I've read that the more you access a drive the more likely the hardware will fail.

My question is, is there a simple way to separate these drives again without having to reinstall the OS and my programs?
January 21, 2010 4:53:36 AM

so your saying that u got a 1 terabyte hard drive instead of 2 5oo gig hard drive rite? If thats the case all you have to do is go to
1st control panel open administrative tools.
2nd in administrative tools open up computer managment
3rd Storage folder
Disk management
4th Right click on the 1 terabyte drive probably your C: drive click shrink Volume
shrink it to the desired size you want then you will have whatever is leftover as unallocated space right click on the unallocated space create new volume assighn a drive letter and format and your done
m
0
l
January 21, 2010 5:09:05 AM

No, I have two 500GB drives registering as a single terabyte drive. I want them both to show up as separate drives.
m
0
l
Related resources
January 21, 2010 5:29:16 AM

Have you done some RAID configurations before installing the drives? I'm not sure but it looks like a RAID 0 config to me.
m
0
l
January 21, 2010 6:29:27 AM

I didn't set the drives up if that's what you mean, but RAID 0 sounds right. I haven't the slightest clue how to unlink them, though. Do I do that through the OS, the BIOS, or should I get some kind of software? Will I need to reinstall Windows? Thanks.
m
0
l
January 21, 2010 7:17:20 AM

well i dont know much about raid but i think u would have to disable the raid setup and reinstall your operateing system
m
0
l
a b G Storage
January 21, 2010 11:46:13 AM

^Yes. You must find your SATA controller in your BIOS, set it to AHCI mode instead of RAID. That is exactly what you will have to do. It will require a complete reinstall of your OS, programs, everything.
Your reasoning for having 2 drives is completely off base though. People do this because it is faster, and if you mess something up, you can reinstall the OS without losing all your data. Usually, you just put the OS on the one drive. But however you do it, saving your data on a second drive is a good idea. Having a backup is an even better idea.
m
0
l
a c 359 G Storage
January 21, 2010 7:51:50 PM

It seems to me it was wrong for the sellers to configure two drives as one RAID0 array without the buyer's request. Of course, maybe OP did not know they were asking that and said OK without knowing. BUT what's the possibility that the drives are configured as a JBOD system, rather than RAID0?

Either way the sellers created a technical problem that the buyer has to correct on his own, and that's bad!

OP, BEFORE you go doing anything to fix this, are you sure you do have the original Windows Install Disk to re-install from? And what about all the other software already installed - can you re-install all that, too?
m
0
l
January 22, 2010 4:16:01 AM

Paperdoc said:
It seems to me it was wrong for the sellers to configure two drives as one RAID0 array without the buyer's request. Of course, maybe OP did not know they were asking that and said OK without knowing. BUT what's the possibility that the drives are configured as a JBOD system, rather than RAID0?

Either way the sellers created a technical problem that the buyer has to correct on his own, and that's bad!

OP, BEFORE you go doing anything to fix this, are you sure you do have the original Windows Install Disk to re-install from? And what about all the other software already installed - can you re-install all that, too?


Yes, I have all the installation software since I figured I'd be doing it anyway. As for the RAID config, I didn't request that they set them up like that but I guess they alluded to it? I wasn't savvy enough to realize that "dual drives" might mean they'd be linked. In the dialog for my build order, I got to choose sizes for a "primary hard drive" and a "data hard drive" so I just figured they'd be separate.

Thank you all for your help so far. One more question though, I've looked up RAID on Wikipedia and I see there are multiple ways to combine disks like this. Paperdoc pointed out, JBOD. I see MAID, SLED, and SPAN/BIG in the wiki too. If it is one of these other types, is the procedure for unlinking them the same (BIOS -> SATA Controller -> change to ACHI?) Thanks again.


===
Update: Okay so I went ahead and explored my BIOS. I saw it was using a RAID configuration so I tried switching to ACHI. When I rebooted to reinstall Windows 7, Windows wouldn't install and only recognized one hard drive. The BIOS recognized both but Windows wouldn't. I had to reboot again, go back into the BIOS, and put it back into RAID config. Then boot from the Windows 7 CD again, format both disks and delete the partitions, reboot again, and THEN switch to ACHI. After that Windows 7 recognized both disks and installed fine. After the install, I had to go to Disk Management to assign a letter to the second hard drive before it would show up under 'Computer'.

So everything works now and I am happy. I'm leaving the above update here so anyone else who encounters this issue can fix it themselves. Thanks all.
m
0
l

Best solution

a c 359 G Storage
January 22, 2010 2:54:51 PM

You've already found a good solution that got you to where you need to be. So this is more for others who are following for their own interest. What OP did not realize (because the supplier did things without telling OP) is that, once the BIOS was set to use the two drive in a RAID mode, then there is a whole other step using other built-in utilities to actually manage the RAID system.

As a system is set up, if the BIOS is set to use RAID mode for the SATA drives connected to it, this triggers about three details. One is that it means you are planning specifically to use the mobo chipset's built-in ability to manage RAID arrays (that is, you are not going to use a separate add-on RAID controller card); the Windows OS will have to have a RAID driver added to it as part of the early installation process (OP did not have this issue since it was done by his supplier); and, you MUST use the built-in tools to set up and manage the RAID array, and there is a specific key to access this utility set.

If the BIOS is set to use RAID mode, you will find early in the boot process that the POST screens include a prompt to press a specific key (maybe CTRL-I, maybe something else) to enter the RAID Setup screens. (If you do nothing, this will time out and proceed anyway.) If you do press this key, you enter a whole set of tools to examine what RAID arrays and drive units exist, to create RAID arrays of various types and configure them, to specify which disk units are assigned to which RAID array and which are NOT involved at all in any RAID array, to diagnose and possibly repair problems with the arrays, and to break up the arrays into separate drives again. There are detailed manuals for all this - sometimes included in your mobo manual, but more often as a large separate document. In OP's case, what he COULD have done had he known this, is to use those tools to break up the RAID0 array into two empty drive units that were ready to be Partitioned and Formatted just like any other brand new empty HDD unit, and ready for installation of Windows on one of them.

By the way, JBOD is not really part of the RAID versions, and technically there are other better names for it like Spanning. It's just that many chipset and BIOS makers who include some RAID ability in the mobo also include JBOD as an option because it's not very complicated and hence easy to add in as a feature.
Share
January 22, 2010 9:33:19 PM

Best answer selected by derp.
m
0
l
!