MBR can only be used as the partition table for disks not exceeding 2.2 trillion bytes in size (technically, it's a limit of 2^32 sectors, which is 2.2 trillion bytes using a standard 512/512e HDD). Once you cross that boundary, you need to use a different form of partition table - the GUID Partition Table. UEFI enters the picture because a UEFI system is required to boot many operating systems--including Windows--from a disk using the GPT layout.
I general, I recommend that disks under 2.2TB that are not expected to grow to that size continue to use MBR for better compatibility. Switching to GPT is a destructive process to any existing data, so it's a decision that is best made when the drive is first initialized. Greg -----Original Message----- From: Hardware [mailto:hardware-boun...@lists.hardwaregroup.com] On Behalf Of DSinc Sent: Wednesday, July 9, 2014 4:44 PM To: hardw...@lists.hardwaregroup.com Subject: Re: [H] GPT_disk_moving?! Greg, While I feel bad for @jjoeuser, I'm now curious about the diffs between MBR drives and GPT drives.This thread shines light on something new based on 'EFI Bios.' As I upgrage my PC's am I creating GPT drives???? If so, and they work, Fine. Just wondering what I may be doing. Thank you for your experience. Duncan On 07/09/2014 11:52, Greg Sevart wrote: > I'm not at all suggesting that it didn't happen; I'm just making sure that the rest of the collective knows that this is a freak incident and that it is not a requirement to do anything special in disk management or otherwise when moving a GPT disk. I've worked with a lot of GPT disks many different hardware and operating system configurations--I'm quite certain I would have run in to this if it were a common occurrence. The root cause for the behavior you experienced is, at this point, a mystery. > > If you have information from an official source prescribing that a GPT disk be unmounted before powering down (if you're removing a disk live it should always be removed cleanly, GPT or otherwise) and relocating, I'd be interested to see it, as I've not yielded anything. > > -----Original Message----- > From: Hardware [mailto:hardware-boun...@lists.hardwaregroup.com] On > Behalf Of joeu...@chronic.org > Sent: Wednesday, July 9, 2014 10:19 AM > To: hardw...@lists.hardwaregroup.com > Subject: Re: [H] GPT_disk_moving?! > > Well, I'm very glad for you, I'm also lucky in the fact that nothing there was to critical and/or can be transferred again. > However, this did indeed happen. I also looked up the info as I have described to everyone & that is a fact. The only other thing I can think of is, I went from an internal sata port to a USB3 ext sata cable? > > Regardless. If you have a GPT drive - UNMOUNT/REMOVE from DISK MGMT! If you forget, DO NOTHING - plug it back in where it was & then REMOVE/UNMOUNT... This may or may not apply to UEFI - I don't have UEFI & I don't care to right now. > > Regards, > joeuser - Still looking for the 'any' key... > > "...now these points of data make a beautiful line..." > >> -------- Original Message -------- >> Subject: Re: [H] GPT_disk_moving?! >> From: "Greg Sevart" <ad...@xfury.net> >> Date: Wed, July 09, 2014 9:42 am >> To: <hardw...@lists.hardwaregroup.com> >> >> >> I don't think that's it--I've moved UEFI to UEFI, BIOS to BIOS, and BIOS to UEFI. >> > > >
