Booting from a 4.0TB raid drive in Windows 7

Booting from a 4.0TB raid drive in Windows 7

Woot!  I just set up my system the last few nights with *three* 2TB drives all connected in RAID 5 setup into a single, 4.0 TB partition – AND I am using that huge bit bucket as my primary boot drive.  Now I have speed from the data striping and redundancy from the RAID.   It’s quite nice so far, but I’m still getting all my old software installed.   However, up until about a month ago – this wasn’t possible with the standard Intel storage controller that comes with almost all the new 2nd generation core systems (or with most RAID controllers).  But getting this magical land to work involves a lot of new information and a good bit of bleeding-edge fighting.

What you need to know:
First off, getting a RAID-ed boot partition larger than 2.2TB involves several pieces that need to work together.  If you only have the first 2, then you can still boot from a single-drive larger than 2.2TB, but you won’t be able to use it in a RAID setup with large partitions.

  1. A motherboard with EFI support
  2. An OS that can boot in EFI mode and supports GPT partitions
  3. A raid controller that can support creating and using boot partitions larger than 2.2TB.

First off, you need a motherboard with an EFI (Extensible Firmware Interface) bios.  EFI bios is the successor to the 20+ year old CMOS bios.  You might remember or have seen CMOS when that awful text screen came up when you hit the power and it would count memory or say ‘Press [del] to enter setup’.  Well, Intel with a lot of other companies finally, happily, heavenly, triumphantly are putting the nails in what had become a painful bit of computing legacy by throwing out CMOS and inventing EFI.  Apple has had EFI bios in their machines for a few years now, and some of the first-generation Core i3/i5/i7 motherboards had EFI support too – but it was spotty and very few things seemed to take advantage of it.  Which brings us to #2 – needing an OS that supports EFI booting and GPT.

If you have a motherboard that supports booting in EFI mode, you still need an OS that supports it and knows how to boot from partitions created with GPT (GUID Partitioning Table). I had an EFI board on my old system, but you couldn’t actually boot in EFI mode unless you used an early Linux distribution with EFI support or until about Windows Vista SP1/Win7 range.  Not only that, but EFI booting only worked on 64-bit versions of the Vista/Win7.  If you’d bought the 32-bit version – then you were out of luck.  The Vista route was also painful because unless you had an install disk that had the EFI boot files on it, you couldn’t actually install Vista in EFI mode.  Early versions of the Vista install CD’s (at least the one I had) didn’t have the EFI boot files.  I never learned if someone who had one of those early disks could return it and get an install disk with EFI boot support.  The reason you needed this is because if you couldn’t boot in EFI mode, you were stuck with the 2.2TB CMOS MBR boot limit.  If you weren’t in EFI mode during the install process, Vista/Win7 will refuse to create a boot partition larger than 2.2TB because it knew a MBR system couldn’t boot from it.  Unfortunately, you couldn’t override this in the install.  GPT booting was usually only supported when the BIOS booted in EFI mode.  So if your OS install disk couldn’t boot to EFI, or wasn’t able to make GPT boot partitions in CMOS mode, you were still out of luck.  As you’ll see, booting in EFI mode is actually more than just having a disk with the EFI files on it.  It’s a two-step approach, but those details will come later.

Finally, Windows 7 64-bit comes along and seems to solve our problems.   The OS install disk has EFI boot support on it.  The install disk is able to make bootable GPT partitions larger than 2.2tb.  Awesome.  But until this last month, you weren’t able to get your Intel RAID controller to make a bootable RAID set larger than 2.2tb because Intel hadn’t finished writing the EFI bios support for it.  You have to check the motherboard manufacturer’s website for a BIOS update – but you should now see new BIOS’s with the new large-partition RAID booting support.  That was the final key to the puzzle.

So, without further adieu, here is how one does this with the following equipment:

  • Asus P8P67 rev 3.1 motherboard (socket 1155 with 8 SATA ports and embedded Intel matrix storage controller) with BIOS flashed to version 1704 or higher
  • Three 2.0TB Hitachi drives all plugged into the Intel SATA ports
  • Windows 7 64-bit install DVD
  1. Back up everything
    The way I did it IS a destructive process and your drives will get erased.  There is no way that I know that you can migrate from a CMOS partitioning system to GPT.  There might be, but fiddling with this sort of stuff in a RAID setup is voodoo and you’ve been warned.
  2. Get and install the BIOS patch
    Be sure you are backed up at this point.  Asus bios flashing seems to always forget my RAID setup when I flash the bios.  In other words, poof – they’re gone.
    I went to Asus and found the newest BIOS patch. In my case it had the very clearly named:
    P8P67 (REV 3.1) 1704 BIOS – 2.2TB or larger HDD can be supported under RAID mode.
    I downloaded the patch file and put it on a USB key.  I then rebooted the machine and entered the BIOS setup.  Asus has a really nice built-in BIOS flashing utility with their new EFI BIOS.  I was able to point it at the USB key, find the image, flash the BIOS, and reboot. If the flashing forgot your RAID drives, then you’ll likely be greeted by a ‘no boot device found’ error.  You cannot safely re-create them if this happened.  The data on them is gone.
  3. Reboot your machine, and create your raid set
    With your BIOS patched, you should now be able to enter the Intel storage manager portion of the boot-up cycle via CTRL-I and create a large RAID set as bootable.  In my case, I selected: create a new set, selected the 3 drives I had plugged in, set the RAID configuration to RAID 5, 64k blocks, and made it bootable.  Save the changes and reboot.
    I find it extremely helpful and safer to shut off the machine, and physically unplug any extra drives you don’t want to get accidentally erased when manipulating RAID setups.  When you create the RAID set, you simply select the drives by serial number.  If you accidentally include a drive that (let say was your backup drive), the moment you add it to the RAID set – the data is gone. Be careful.
  4. Insert your EFI bootable Linux/Win7/Vista DVD, or USB key
    This is where you’ll need to consult your individual motherboard’s docs – and where things can get a little hairy.  For EFI booting on my ASUS board, I have to insert the EFI bootable media (in my case it was the Windows 7 x64 install disk), then reboot/turn the machine on.  Then I had to:

    1. press [DEL] to enter the CMOS setup during boot (with my Windows 7 disk in the drive)
    2. Go to the ‘boot’ menu in the CMOS
    3. Scroll down to list all the bootable devices (CD-Rom/Volume0 RAID set/etc)
    4. I saw the CD-Rom drive I wanted listed at the top, but that’s NOT the one you want.
    5. Keep scrolling down, and at the bottom you’ll see the device listed AGAIN but with the word EFI printed at the start of it.  THAT’S the one to choose.  It tells the system to boot from that device in EFI mode.  If you do NOT see your device listed a second time with the letters EFI in front of it, then that means the BIOS has not been able to find the key EFI boot files on the media you’re using.  In my case, my old Vista x64 disk wouldn’t allow me the option.  Why Asus doesn’t let you just manually set the mode to EFI only booting – I’ll never know.  I think it’s stupid they don’t let you, my old Intel DP35DP board let you do that…
    6. Select the device with the EFI bootable disk in it and tell the bios to boot.  You’ll notice that the fonts are different on startup, and that the cursor will do a funny indented thing during the boot cycle.  This tells you it’s in EFI booting mode.
  5. Boot the Windows install disk and create your partitions
    You should see the windows installer start just as normal.  When you get to the partitioning menu, you can select the auto-create option, and that should work.  However, this step is the MOST finicky and the place where you’ll find if you really are in EFI mode or not.  I chose the manual creation of the partitions and told it to make me the biggest one.  Sure enough, it said 3.7TB.  By default, you will get 2 other 100MB partitions created by windows for recovery purposes.  You can live without them, and they do not show up as drive letters in your system after it’s up.  Instructions on how to create your system without those extra partitions are here. The important thing is that you make SURE the partition is the right size at this point.  If it won’t create a 2.2+TB partition, or if it says it did, but the size is 2.2TB, then you’re not really in EFI mode or the Vista disk you have isn’t EFI bootable.  After you see that beautiful, full-sized partition – you might get a warning about the partition being potentially unbootable due to it’s size -but you can safely ignore it.  Just make sure that it actually created the partition.
  6. Finish the OS install as normal
    From here on out, follow the Windows install as normal.  On reboot, the motherboard will detect the GPT partition and properly boot in EFI mode automatically from here on out.  You’ll never need to do the selective EFI bios boot again.
  7. Install the Intel matrix storage manager software
    This really excellent software should be on your system.  If you have a UPS device on your system, I highly recommend turning the buffering on.  It allows for the drive read/writes to also be buffered in system memory.  It is dangerous without a UPS because a power loss means anything in the system buffer is lost, but delivers a noticeable speed improvement if you do have a UPS. Also, make sure to ‘Initialize’ the drives.  When you’re just fresh installed with windows, this is instantaneous.  Finally, this software is great because it’ll report any SMART errors your drives start throwing.  If a drive starts dying, it’ll warn you (hopefully) long before it finally goes bad.  I’ve seen this software work exactly as advertized when one of my own drives started failing in a previous setup.  It also gives you information about which drive is failing so you know which one to pull out and shows you status of any rebuilds when you swap in a new one – which can happen WHILE you’re actively using the system.  How cool is that?
  8. Done!  When you get into windows, you should have one large C: drive with all your space and no extra ‘boot’ drives!

I know many Linux afficianatos cringe at big bit buckets like this.   Put your swap on another partition!  Make a partition for your programs files!  Make a tiny one for your boot partition!  This is all well and good if you like micro-managing.  I hate micro-managing.  I hate extra drive letters.  We’re in the f-ing 2000’s now people!  3TB drives are $150, and 2TB drives are $65.  RAID comes built into boards for free.  Storage is a commodity.
I use Windows for most of my daily game playing/tv watching/etc and don’t want to futz with the headaches of multiple partitions.  I want to play games, watch tv, and surf the web.  I don’t want to have to worry about how big to make a partition for my programs files or data files or worry about how big my boot partition is on windows.  What if I over or under-guess?  I get to either re-install or test my luck with a partition resizer or have some programs one place, and others somewhere else.  Or the fun of every. single. time. I install a program, I have to select a custom install and pick a different drive letter.  Windows patches often automatically install in the system32 directory – what if a new service pack is too big to fit on my tiny boot partition?  It makes no difference for security if my boot is on a different partition than my data or programs.  Creating a separate partition on the same drive just for the swap file is no gain.  Unless it’s on another physical drive, you’re not gaining any speed in Windows.  And even then, I have 16GB of memory in my machine (and you can too – it’s ridiculously cheap at $60/8GB of high-quality DDR3 ram), I never swap anymore.

In short, I never have to worry about my space or what I’m putting where.  We’re not in the 70’s anymore where drives were real investments.  They’re cheap, replaceable commodities now.  I have a RAID 5 which means I’m getting the best of both speed and redundancy all in one place, and it’s details are taken care of by the hardware.  What more could one ask for.

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