Q: Bootcamp partition has disappeared after upgrade to Yosemite 10.10
Hello Loner T,
I've been following the threads of people with similar issues for the last couple of days now. I downloaded Testdisk and GPT disk both. And I've been trying to follow the directions as best I could on my own to see if I could re-set/re-write the GPT and MBR entries. My situation is a little different from the others in that I manually opened my iMac and installed an SSD which populates /dev/disk1(for recovery volume) and /disk2/ which is my boot drive. /dev/disk0 the internal 1TB drive became extra storage and location for the Bootcamp partition. So following these directions initially to pin down where on Disk0 things were located I narrowed it down to /dev/disk0s3
- diskutil list
- diskutil cs list (to find if Core Storage is the culprit)
- Download GPT Disk from sourceforge.org and install it.
- sudo gpt -vv -r show /dev/disk0
- sudo fdisk /dev/disk0
Here's the output from each of the steps, the beginning of the tests----------------------------------------------------------
-------------------------------------------------------------------------------- -End of Tests-----------------------------------------------------
So /dev/disk0s3 is the location. But I'm having real difficulties now getting further as I tried this command just to see if I could find the 'R.NTFS' entry in the hexdump from the dd command:
sudo dd if=/dev/rdisk0s3 count=1 2>/dev/null | hexdump -C
Ambiguous output redirect
Do I have that commandline correct?
Also I've done a full run of Test disk in Quick Search and Deep Search that I can post if needed. I'm finding it's very odd compared to what I've seen other people posting so far. I've got 2 complete Windows partitions with what looks to be the same files in both locations. I did extend the volume at one point to boost it up to 250GB. Don't know if that's causing the GPT/MBR to show a total of 8 entries in Testdisk. But that's what I'm seeing when I run it. Will await any further steps or directions you might have. I'm hoping this is quick fix. But I'm willing to do a full GPT re-wrtie/reset and an MBR rebuild if necessary and of course the Windows Recovery if it comes to that. I cannot thank you enough for being so generous with your knowledge and expertise, it's been a real education in the low level vagaries of disk management on the Mac for the past 2-3 days.
OS X Yosemite (10.10)
Posted on Nov 15, 2014 6:22 AM
MS Data 1465253888 1952602111 487348224
MS Data 1465253888 1953523704 488269817
Both of these start at the same offset so they look like the same partition, hence the content looks the same.
If you look at the gap between GPT#3 and #4 which starts at 1465253384 (your two entries are 4 bytes further higher), this looks to be the best available candidate. I suggest using the second entry since it is larger in size.
You need to delete GPT#4 and recreate it with the second entry which start/end/size triplet. If you need the steps, post back and I can cut/paste from a different thread.
Posted on Nov 16, 2014 6:41 AM




