I think you are going to have a problem if you try that. Bootcamp won't work if there are more than three partitions on the Mac. You already have the hidden EFI and Recovery partitions, plus the main OS partition, so that makes three and Yosemite would be a fourth. I have seen some work around for this (pre-Yosemite), but have no idea if they would work with Yosemite.
i had mavericks on 1 tb hdd with bootcamp i installed yosemite on top of mavericks didn't affect bootcamp then moved the 1 tb hdd to optical drive bay and installed an SSD in main bay and installed mavericks on it all 3 operating systems are working fine
Boot Camp and Boot Camp Assistant are completely different things. Boot Camp will work just fine, I have Mavericks, Yosemite and Windows 8 all installed and working right now. I doubt Boot Camp Assistant can make another partition when you have a few partitions already, but you don't ever need to use Boot Camp Assistant to install Windows, just use Disk Utility.
In my experience, Boot Camp Assistant doesn't like to work with a drive that's been partitioned by anything but itself, Boot Camp doesn't care at all.
Obviously I didn't upgrade my install of Mavericks, but I don't see why an upgrade would behave any differently. All of this said, have backups!
I upgraded 10.9 to 10.10, with bootcamp partition on the same drive. No problems for me.
Thanks for the info. I think the problem comes in when you try to make a second partition and install Yosemite there and it makes that into a core storage volume.
Just curious, did your install over top of Mavs turn the partition info core storage?
Not sure what you mean here.
Image
Some are reporting the Yosemite install converted the partition from a normal Mac OS Extended partition into a core storage volume. There is a support doc. here on page 7 that talks about it a bit.
It had been used for Filevault encryption and Fusion drives, but Yosemite seems to be using it on just standard unencrypted installs.
If you look in Disk Util (screenshot) it will look like this.
Here ya go:
Ahh.... so it did convert it. Thanks for taking the time to reply.
Is that good or bad, that it converted it?
It does not create any issue that I can tell beyond not being able to resize the partition. There was a post in another Yosemite thread where a user reported this to Apple as a bug and they closed his bug report and told him this is by design. He was not told why they did this though.
I would just leave it alone. Hopefully at some point someone at Apple will reveal the logic behind this.
Boot Camp and Boot Camp Assistant are completely different things. Boot Camp will work just fine, I have Mavericks, Yosemite and Windows 8 all installed and working right now. I doubt Boot Camp Assistant can make another partition when you have a few partitions already, but you don't ever need to use Boot Camp Assistant to install Windows, just use Disk Utility.
In my experience, Boot Camp Assistant doesn't like to work with a drive that's been partitioned by anything but itself, Boot Camp doesn't care at all.
Obviously I didn't upgrade my install of Mavericks, but I don't see why an upgrade would behave any differently. All of this said, have backups!
I upgraded 10.9 to 10.10, with bootcamp partition on the same drive. No problems for me.
I installed Yosemite on a separate partition and lost access to my Boot Camp paprition. I could soo it but could not access it.
Good news about being able to reinstall Windows without using BootCamp.
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Thats not the issue being discussed. If you install Yosemite on a separate partition (thus having 3 partitions) chances are you would lose access to Boot Camp (thats what happened to me and a lot of others!).
you lost access to boot camp partition because you partitioned a hard drive that has bootcamp installed but if you just upgrade Mavericks to Yosemite or wipe Mavericks partition and clean install Yosemite you shouldn't have any problems with bootcamp
and if you go to disk utility it gives u a warning that the hard drive is partitioned for Bootcamp and changing the partition map will make windows Unbootable.
you can only have 2 partitions on a hard drive if you want windows (excluding the boot efi and recovery)
you lost access to boot camp partition because you partitioned a hard drive that has bootcamp installed but if you just upgrade Mavericks to Yosemite or wipe Mavericks partition and clean install Yosemite you shouldn't have any problems with bootcamp
and if you go to disk utility it gives u a warning that the hard drive is partitioned for Bootcamp and changing the partition map will make windows Unbootable.
you can only have 2 partitions on a hard drive if you want windows (excluding the boot efi and recovery)
I installed Yosemite on a separate partition and lost access to my Boot Camp paprition. I could soo it but could not access it.
Good news about being able to reinstall Windows without using BootCamp.
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Thats not the issue being discussed. If you install Yosemite on a separate partition (thus having 3 partitions) chances are you would lose access to Boot Camp (thats what happened to me and a lot of others!).