Raid 5 on Windows 7

jimlenz

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I just build my htpc and all works great. I setup the raid 5 through the bios and installed my OS, windows 7 RTM on my os HD. So I have the 640gb WD os drive and 3 WD 1tb drives configured for raid 5.

When I go to computer, disk management and format disk. The raid 5 option is greyed out. The only option at this point is to create a new volume. I am confused at this point on what to do. I know windows 7 doesnt support raid 5 but since I already have the hardware raid setup through the bios, what else do i need to do. It looks like my only option is to create the volume, format the drives and go from there.

I would appreciate any help and advice you can provide me.

Thanks

Jim
 

440bx

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Jim,

if you have setup the RAID correctly in the BIOS, when you go to disk management you should see only 1 drive for the 3 drives that make up the RAID 5.

if you see 3 1TB drives then your RAID isn't configured properly in the BIOS. Windows should not be seeing individual drives. The RAID card should present the three drives as a single volume to Windows.

You probably need to double check the RAID configuration in the BIOS.

Another possibility is, if you did not allocated the entire 1TB to the RAID 5, then Windows is simply seeing the unused space which you could format as individual partitions.

HTH.
 

jimlenz

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What I see in disk management is the os drive and the raid 5 drive. So they are configured properly. The reason I say that is the raid 5 drive show 1.8 tb of space whiich is equal to 2 of the drives.

So I assume since the hardware is setup right, then I can go ahead and format, crerating the new simple volume?

Thanks.
 

440bx

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Follow Bullheaded67's instructions :)
 

claudiofranck

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It is correct to see only 1.8 TB on a Raid 5 Volume. you have 3 1tb drives. How ever hard drive manufacturers regard 1 TB as 1000 MB where it should be 1024 MB so in reality you get a little less "real" space.

Raid 5 uses at least 3 hard drives, 2 stripping the data and one for parity. It is used to have a safer storage medium where if one drive fails the array is still functional though with degraded performance giving you enough time replace the failed drive or backup the data. The drive used for parity information does not count towards storage sapce.

Regards
 

surda

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yea and keep in mind, that windows cant have a partition bigger or equals to 2TB, so u gonna have to create partitions to divide it into smaller than 2 TB.

maybe you already have smaller partitions just wanted to give you a tip on that one.
 

wuzy

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That's the limitation of MBR. GPT overcomes that limitation and has been supported since Vista/Server 2008. GPT isn't bootable, but in jimlenz's the OS boots off the 640GB drive anyway.
 

Giotto

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So if you see a single drive where there should be three, you go ahead and create a simple volume and that formats the drive which means that you're finishing up your (hardware) Raid 5 set-up?

I don't understand why they added the "New Raid-5" option if this is how you do it, it seems to just confuse the heck out of me (and others, obviously from the threads I've seen).

What I'm really looking for is verification that this does, indeed, finish the Raid 5 set-up inside the Win 7 OS that I started in the BIOS using the Raid hardware controller. I want to make sure before I do get a drive failure and then find out I had no plan B to restore any lost data.
 

reconrad37

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I don't think you are understanding it correctly... if you set up the raid in bios at the hardware level then the OS will see it as ONE drive period. That's all it knows about that/those drives. There are no further configurations or finishing of a configuration. If done right, you "finished" the configuration in BIOS. The OS will write to it like it is one drive... just allocate it, create partitions etc and thats it.
 

Giotto

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That makes sense. Like I said, I was just looking for verification that I was finished with the setup.

Thanks.
 
G

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I came across this thread and had a question. I was required to install Win7 on a Poweredge 840 with Server 2003 and a RAID5 hardware config made possible by a PERC 5i controller and 4 250GB HDD's.

After installing Win7 I opened Disk Manager and saw one disc (as it should show) Total size 696.75GB with C: 232.83 GB NTFS Healthy PLUS 463.92 Unallocated .

The OS is on DISC 0 listed as C: The other three discs are listed as UNALLOCATED. I understand one of the discs is for Parity. DO I NEED TO MAKE THIS UNALLOCATED SPACE A SIMPLE VOLUME?

Also, should I keep the disc BASIC or change to Dynamic.

Any help is welcome!

Thanks
 

HDRide

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Hello everyone,

I recently had this same issue with setting up a new system I built. I wanted a SSD boot drive and 3 500GB for Raid . Then there is a 1 TB drive for general use. I looked everywhere I could think of for an answer to the Raid 5 grey out condition as noted above and found nothing. I ended up here and realized there was one place I usually check and didn't, Microsoft MSDN. I think I may have found the answer to all of your Windows 7 and Raid 5 questions. Please check this link: http://support.microsoft.com/kb/975453

I have not tested it myself yet but it seems to be a viable answer to this elusive question. I saw a few places that Windows 7 just didn't support it but instincts told me different. Why would Microsoft even bother to put the item on the menu if only to be a grayed out item. As one person wrote it would add a few lines of code to the millions already there and some driver / dll files.

That driver and code does exist according to the article and I'm about to give it a try.

The drawback to this trial is in my BIOS I can't select which drives will be the RAID drives, as they all become AHCI active. For some reason the DVD unit has issue with this and is unusable at boot time. I believe windows will take care of this anomaly and add it to the devices after OS boot has finished.