Q: Error: -69879: Couldn't open disk
Hi all, having a bit of a nightmare recently thanks to Yosemite update .
I have a 2007 iMac which has a 1TB HDD partitioned (750 Mac, 250 Windows XP). Over the past 2 years my Mac side was sluggish and freezing constantly, it improved slightly by Mavericks and I also upgraded the RAM. Yosemite seemed even better and I thought it was coming back from the dead but after the most recent update the iMac will reboot at about 50% load during boot. I was stuck.
Luckily I entered my XP partition and using some software backed up my important files from the Mac partition. I'm now free to erase the Mac partition and reinstall the OS, hoping it'll appreciate the clean start after all these years. I first thought the hard-drive was dying due to the freezes but my XP partition runs superfast with no problems and it's on the same disk. Anyway, booting with CMD + R and entering Disk Utility, the icon for the Mac partition is greyed out - I can't repair the disk or erase it right clicking and attempting to mount it fails also. When attempting to erase the volume via terminal using; 'diskutil eraseVolume JHFS+ Mac /dev/disk0s2' I get the error: -69879: Couldn't open disk.
Any other way I can format this without losing my Windows partition?
iMac, OS X Yosemite (10.10.2)
Posted on Feb 19, 2015 7:24 AM