Select Macintosh HD, not WDC WD5000… otherwise you’re trying to erase the entire drive, which contains the recovery partition. You’ll want to select the volume on the disk, not the disk itself.
Regards Sam MacAmbulance Ltd. Providing Affordable Mac/PC Support and Web Development Sam Mullen +44 (0)7747778022 <tel://+447747778022> i...@macambulance.co.uk <mailto:i...@macambulance.co.uk> www.macambulance.co.uk <https://www.macambulance.co.uk/> MacAmbulance Ltd. is a registered company in England & Wales, registration number 8466597 This email is intended solely for the addressed recipients and may contain privileged or confidential information. If you have received this email in error please notify the sender and delete the email immediately. > On 9 Apr 2017, at 21:32, itsagr...@icloud.com wrote: > > Hi all, > > I want to erase my iMac’s HD and reinstall Sierra before selling it. > > I’ve rebooted, used CMD-R and got to the macOS Utilities menu where I have > tried to erase the disk but it won’t. > > I’ve selected WDC WD5000AAKS-402AA0 Media. > > First Aid says it’s all fine. > When I run Erase it shows: > > Unmounting disk > Couldn’t unmount disk. > Operation failed… > > I’ve tried to use diskutil in Terminal with the force option to unmount > /dev/dsk0s2 but it says it can’t unmount it either. > > Any ideas? > > Cheers, > > Stephen > > > "More than any other time in history, mankind faces a crossroads. One path > leads to despair and utter hopelessness. The other, to total extinction. Let > us pray we have the wisdom to choose correctly." - Woody Allen > > -- > You received this message because you are subscribed to the Google Groups > "Sussex Mac User Group" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to smug+unsubscr...@googlegroups.com. > To post to this group, send an email to smug@googlegroups.com. > Visit this group at https://groups.google.com/group/smug. > For more options, visit https://groups.google.com/d/optout. -- You received this message because you are subscribed to the Google Groups "Sussex Mac User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to smug+unsubscr...@googlegroups.com. To post to this group, send an email to smug@googlegroups.com. Visit this group at https://groups.google.com/group/smug. For more options, visit https://groups.google.com/d/optout.
