Recovering an image backup with UEFI BIOS

mojoman317717

Distinguished
Sep 15, 2010
59
0
18,630
Have a T110 server with Windows Server 2008 R2. It currently boots with the standard BIOS. I want to change the disc situation from two discs in a RAID 1 array to four discs in a RAID 5 array using 2tb discs. Everything about this seemed pretty straight forward until I discovered that I can't have partitions larger then 2tb when booting to the BIOS with MBR disc format. Apparently booting to UEFI and using the GPT disc format WILL allow for larger partitions. So this brings about a few questions.

1) If I make an image backup of the current situation (OS and everything) and then restore that to the new RAID 5 array, will the current partitions be preserved and will the remaining 7tb of space be accessible and usable? The key issue here is really the remaining space. I think the answer is no, but I really would love an intelligent confirmation.

2) If I make an image backup of the current situation (OS and everything), then change the boot settings in the BIOS to boot with UEFI, can that image backup be restored in that new environment? I'm guessing the answer to that is also no, but again would love a confirmation.

3) Does this leave me with no other option, but to reinstall the OS in the new UEFI environment, and then restore all the other files into newly created partitions?

Holy crap this stuff is complicated! I think my brain is going to explode.
 
Solution
Windows requires UEFI in combination with a GPT partitioned disk in order to be used as a boot disk. Without the availability of EUFI you won't be able to boot windows from a GPT partitioned disk.

Do you need a bootable drive that large? You can always put your OS on a single disk (less than 2.2Tb for MBR partition) and put all your data on a raid array that is partitoned as GPT.
Making an image of the drive makes exact copies of the drive including partition tables, in this case MBR, so I don't think this will work for you.

You will most likely need to do a clean install of the OS. You can however do a file backup and backup all your documents and such. After the clean install of the OS, you can do a file restore and restore your documents and data.
 

mojoman317717

Distinguished
Sep 15, 2010
59
0
18,630
Thanks Hawkey22, that's what I thought, but I greatly appreciate the confirmation.

So I will do a file backup, then create the new RAID 5 array in UEFI mode, reinstall the OS, create whatever partitions I want and then restore the files. Sound about right?

 

mojoman317717

Distinguished
Sep 15, 2010
59
0
18,630
Ughhh! Just discovered a new worse problem. According to the Dell T110 manual, when RAID is enabled in the BIOS, UEFI mode is disabled. What were the odds???!!! Any idea why it would be that way?

That pretty much brings me back to square one.

So, from the beginning: If I start with a 1tb image backup, what will happen to the remaining 7tb once I've restored the backup to the new RAID 5 array? Will the OS or BIOS see the entire 8tb array (7tb after the restored backup) and will I be able to partition it? I'm ok with a number of 2tb or smaller partitions, but I have a big problem if the BIOS or OS do not even see the storage space.

Any idea what will happen.
 
Windows requires UEFI in combination with a GPT partitioned disk in order to be used as a boot disk. Without the availability of EUFI you won't be able to boot windows from a GPT partitioned disk.

Do you need a bootable drive that large? You can always put your OS on a single disk (less than 2.2Tb for MBR partition) and put all your data on a raid array that is partitoned as GPT.
 
Solution

mojoman317717

Distinguished
Sep 15, 2010
59
0
18,630
Sorry for the slow response. It's taken quite a bit of work to get to the bottom of this, but I have confirmed that RAID CAN be enabled from UEFI mode. For unknown reasons if RAID is enable in BIOS mode, then UEFI becomes disabled. BUT, it you first enable UEFI from BIOS mode, then enter UEFI mode, you can enable RAID from there.

I'll post back the final results after I have installed the RAID 5 array this weekend.

Thanks for all the help everyone.
 

mojoman317717

Distinguished
Sep 15, 2010
59
0
18,630
Well it turns out that RAID is disabled from within UEFI. No thanks to Dell technical for the misinformation.

Fortunately I was able to creat two virtual discs one small at 100gb for the OS and one with the remaining space. Then from within disc manager after OS deployment I converted the large disc to a GPT dynamic disc.

It turned out to be really easy. It's running great at 50-60mbps on both reads and writes. Though the read speed seems a bit slow for a 4 disc RAID 5, but I'm still tweaking it.

Thanks for all the help everyone!
 

donnasander

Honorable
May 2, 2013
5
0
10,510
Well, since you now figured all that out, I wanted to ask you what software you used for the backup? (or did you do one?) I need to find software that has no problem with dynamic disks and UEFI.