Q: Win 8.1 Upgrade causes GPT/MBR Mismatch
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Feb 11, 2014 10:27 PMby sakman74,i mostly use clonezilla in the windows world. since i bought a mbp and plan on doing dual boot, i plan to use clonezilla to backup my system. but my backups have been mostly disk images, not specific partitions. I too plan to install windows 8 then upgrade to 8.1 via the microsoft store.
not sure if i'll experience an issue using clonezilla yet, because i've not yet done a backup of a disk setup with more than one OS.
Are you making a backup of the entire disk with the MBR, or just specific partitions ? this depends on what backup method you choose in clonezilla.
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Feb 11, 2014 11:06 PMby sakman74,clonezilla will allow you to backup individual partitions or the entire disk, with any MBR data that's present. i'm a big fan of clonezilla, been using it for years. whenever i did wind up in a bind with my windows install, i would restore the disk from a backup and be back up and running in less than a 1/2 hr. backups for about 40GB of data only took around 10-15 mins. hands down the best free backup/restore tool out there.
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Feb 12, 2014 6:02 AMby Mark Ulmer,I'm using Clonezilla to make an image of the entire disk (all partitions). I like it because I can use one tool to back up both operating systems at the same time. Also, it only copies sectors that are in use, unlike some disk imagers that make a bit-for-bit copy of everything including unused space. So, it's fast.
If you do install Win 8 and then upgrade to 8.1 from the store, make sure you check after the 8.1 upgrade completes to make sure it hasn't resized your BOOTCAMP partition.
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Feb 12, 2014 7:23 AMby sakman74,Bob,
for my case (different from the OP's), I will hold off on installing 8 on my mbp. Just because I don't want to risk the Windows 8.1 installer tinkering with Partition resizing and MBR disparities.
So now it's a waiting game for me, not ideal though because I am hanging onto my HP laptop until I've completed the Windows transition on my mbp sucessfully.
Mark,
Thanks for the advise. The best option for me (although not ideal at the moment) is to wait it out for Bootcamp driver support, then I can install 8.1 straightaway rather than do it in 2 steps (8 --> 8.1). good thing I peeked at this discussion, I would have otherwise done the installation beginning with 8.
Clonezilla is quite powerful and I like it's speed and versitility. It also lets you restore partitions to larger partitions in the event of upgrading the drive/storage. Don't think it works with full disk images though ....
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Feb 14, 2014 8:24 AMby sakman74,So I wound up going in the same direction as the OP for getting windows 8.1 on my machine. My dilemma was that at the time I went to buy Windows, Boot Camp didn't support 8.1, so I wound up with Windows 8.
I thought I could install 8.1 clean if I downloaded the ISO but it wouldn't work with a Windows 8 Product key.
Anyway, I installed 8, then upgraded to 8.1 and everything seems fine. I can boot into either OS. But I should check to see if the MBR is proper according to the Partition size.
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Feb 14, 2014 2:35 PMby Mark Ulmer,Well, for one thing, Clonezilla won't work. That's what first clued me in that I had a problem. For another, if you ever attempt to upgrade OS X (to Mavericks, for instance), you will likely lose your BOOTCAMP partition. There are many reports of Mavericks upgrade problems when any partition changes have been made.
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Feb 15, 2014 1:15 PMby Mark Ulmer,Yes. First, download gdisk (URL in the OP) and run the installer package. Then run gdisk from a terminal window and run the v (verify command). If verify indicates no problems, then you're good to go and can just type "q" to quit. However, if it shows something like this, then you have the problem:
sudo gdisk /dev/disk0
Command (? for help): v
Warning! Mismatched GPT and MBR partition! MBR partition 4, of type 0x07, has no corresponding GPT partition! You may continue, but this condition might cause data loss in the future!
Identified 1 problems!
Next, display the MBR partition table and make note of the start and end sectors for your BOOTCAMP partition. This should be partition 4 unless you've added additional partition(s), which is not officially supported by Boot Camp. It should show something like this:
Command (? for help): r
Recovery/transformation command (? for help): o
Disk size is 1953525168 sectors (931.5 GiB)
MBR disk identifier: 0x7C170CB2
MBR partitions:
Number Boot Start Sector End Sector Status Code
1 1 409639 primary 0xEE
2 409640 975693095 primary 0xAF
3 975693096 976962631 primary 0xAB
4 * 976963584 1952806911 primary 0x07
Next, display the GPT partition table information. Compare the start and end sectors for partition 4 to the MBR partition 4 start and end sectors. Most likely the start sectors will match, but the end sectors will be different.
Recovery/transformation command (? for help): m
Command (? for help): p
Number Start (sector) End (sector) Size Code Name
1 40 409639 200.0 MiB EF00 EFI System Partition
2 409640 975693095 465.1 GiB AF00 Customer
3 975693096 976962631 619.9 MiB AB00 Recovery HD
4 976963584 1953523711 465.7 GiB 0700 BOOTCAMP
Next, delete the GPT partition 4. (Note: this does not delete the actual partition from disk. It only deletes gdisk's in-memory representation of the GPT).
Command (? for help): d
Partition number (1-4): 4
Now, create a new partition 4 using the start and end sector values from the MBR partition 4.
Command (? for help): n
Partition number (4-128, default 4): 4
First sector (34-1953525134, default = 976962632) or {+-}size{KMGTP}: 976963584
Last sector (976963584-1953525134, default = 1953525134) or {+-}size{KMGTP}: 1952806911
Current type is 'Apple HFS/HFS+'
Hex code or GUID (L to show codes, Enter = AF00): 0700
Changed type of partition to 'Microsoft basic data'
Now, change the name of the new partition 4 to BOOTCAMP:
Command (? for help): c
Partition number (1-4): 4
Enter name: BOOTCAMP
Run the verify command. It should report no problems. If it still reports a problem, quit (q command) and start over.
Command (? for help): v
If everything checks out, write new partition table to disk and exit.
Command (? for help): w
Reboot and test your dual boot setup to verify all is working correctly.
