Volume Erase Failed

[Skrap]

I want to reinstall OS X Yosemite on my 27" iMac, I power my iMac by holding the cmd + r key and i go into disk utility and when i click on Macintosh HD and select Mac OS Extended (Journaled) it says: Volume Erase Failed with error couldn't unmount the disk.

Please Help !

 

[Weaselboy]

Run the command below in Terminal so we can see the disk format/layout and try to help.

diskutil list

 

[Skrap]

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 999.3 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

 

[Weaselboy]

I was thinking maybe you had FileVault on or perhaps Yosemite had converted the drive to core storage, but neither appears to be the case.

Just to clarify, you did a command-r boot to recovery and from there launched Disk Util. Then go to the erase tab and select Macintosh HD then Mac OS Extended (Journaled) in the dropdown, then apply that change?

 

[Skrap]

Yep, i pressed cmd+r when it was booting and went to Disk Utility and clicked erase on Macintosh HD and i also selected Mac OS Extended (Journaled). It was already selected in the list. Filevault is turned off.

 

[Weaselboy]

Yep, i pressed cmd+r when it was booting and went to Disk Utility and clicked erase on Macintosh HD and i also selected Mac OS Extended (Journaled). It was already selected in the list. Filevault is turned off.

Hmm... why are you doing this to begin with? Was there some disk issue that was causing problems perhaps and that is showing up here also.

 

[Skrap]

Im doing this because the systems files are corrupted and i can't see any lines in finder in column view

 

[Weaselboy]

Im doing this because the systems files are corrupted and i can't see any lines in finder in column view

I don't think a reinstall is going to fix this. It looks like you have a failing drive and that is the underlying issue here.