Hi – best way to securely wipe a macbook prior to selling on. Tried to mount an OS disc and do it that way but am getting nowhere fast. Tried doing it via terminal but the disk is mounted so I can’t do a diskutil Secureerase command.

Help! 🙂

Boot into recovery mode and use disk utility

http://osxdaily.com/2012/02/08/repair-boot-disk-mac-os-x-disk-utilit/

http://support.apple.com/kb/HT3680

What @torso says if you want to handover a totally clean machine, his suggestion may end up setting the OS back to the version the machine was purchased with though, not sure. If you do that make sure latest OS is loaded to ensure best resale value as new buyer might not want the hassle.

Brilliant – will have a crack at this later.

Just done the same.

download dban, burn the iso to a cd with diskutility.
dban wipe the drive.
install OS from original disks.

(I’ve used dban for ages across multiple OS’s….i tend to trust it more than anything else for wiping)

I tried a secure erase on a mac disc once and it was going to take about 3 days. What are you worried about someone finding?

For a machine I was selling to someone I knew I simply created a new user and deleted the others.

When selling on eBay I’ve done an clean OS install and left it at that. If someone wants to steal your identity there are much easier, cheaper and less traceable methods than buying your old laptop.

apple S will take you into single user mode, without the discs mounted. should be able to wipe it in there with a command.

You should be able to format it with the install disk though, booting into disc utility.

Not worried about them finding much, a format just removes all the software and user settings in one go.

Will try out Dban if I can’t just format as normal.

You mean you haven’t been using FileVault already?

If not, I’d login as admin and secure erase all the users’ home folders. The admin account contains no stored passwords, important keychain components or other items of value… if you’ve been computing safely.

Then I’d boot from an external disk, erase the drive, reinstall OS X and leave it.