If the worst happens and your Mac crashes and won’t start, what can you do? Of course you should do Time Machine backups regularly. Unless you do that, you won’t get your machine back exactly as it was if trouble strikes, but it’s worse than that.

The recovery disk, a secret partition which is part of the Recovery System, resides on your system drive, and while it contains useful tools to recover your data and move on, it’s no good if you can’t get to it.

In this article, we talk about the Recovery Disk hiding on your system, and how to prepare for the worst case scenarios by making a copy of it as a bootable recovery disk.

I am Broken; Recover Me

The Recovery disk is the best friend you never knew you had. Tucked away in a 650Mb partition on the system drive is a set of tools you can use to fix and restore your drive should it crap out on you.

It’s not an installer. It’s a fixer, a toolkit. It props up your broken machine long enough so you can reinstall or restore your system. With the tools it contains, it can:

Restore your Mac from a Time Machine backup

Verify and repair connected drives using Disk Utility

Check your Internet connection or get help online using Safari

If all else fails, install or reinstall OS X

To start your computer with Recovery, restart and hold down “Command + R” before the startup chime.

Saviour in the Cloud

Maverick and Yosemite have a feature that when you have Internet access, you can boot your machine from a Recovery partition up in the cloud. But this doesn’t save you if your drive is unstable and you have no Internet access, which of course can happen.

One option is putting the recovery partition on an external drive by using the Recovery Disk Assistant (download it here).

First, you will be asked if it’s okay to use this software:

Note: if you want to use an SD card, here’s a tip. Putting the card into the internal SD card slot in your Mac won’t work as the Recovery Assistant only polls the USB ports. Put your SD card into a USB adapter, and it will be seen.

Now choose the volume you want to store the Recovery Disk on:

The Assistant will now create your external Recovery drive.

Once you have a recovery disk, you can recover your Mac when trouble strikes.

To recover your machine, simply boot or reboot holding down “Command + R” and your Mac will search, first the recovery partition, then the Internet and any external drives you have made with Recovery tools on them and then load the tools.

That’s all good, but the Assistant app is limited. It only allows the creation of OS X Recovery disks on an external drive or flash drive via USB. Can you make an optical disk?

Seeing the Unseen

To burn an optical Recovery Disk (and a CD will suffice, as it’s deliberately only 650Mb in size), you will need to locate the hidden Recovery tool files on your drive and burn them to a disk.

Open Disk Utility. You will notice the menu probably looks like this:

What we are looking for is the Debug menu. If it’s not there, you need to activate it with Terminal. Close Disk Utility (because the menu won’t activate in an open program), open Terminal and type the following:

Open Disk Utility again, and you will see the Debug menu is now showing between the Window and Help menus.

Next use the menu and go to “Debug -> Show every partition.”

Now in the list of partitions and drives, you should see a ghosted entry for “Recovery HD.”

Burn it!

Now that you can see the Recovery HD partition, you can burn it to a disk. Select the drive image you just created:

Of course, if you have one of the new Macs which has no Superdrive, you will need an external DVD/CD burner attached. Select the Recovery HD partition from the list, and click “New Disk Image” from the icons along the top:

While you can save a tiny bit of space when saving Recovery Image by checking the compressed box, you don’t save that much space, and compressing it adds a little uncompressing time when unpacking it for burning. But it’s your choice.

Once you have a disk image isolated and saved to disk:

You can now burn it onto a CD. Select the image on the list on the left-hand side and click Burn on the top menu:

Once the disk has burned, test it by booting from it. Hold down the “C” key as you start or restart.

Another thing you might want to do for safety’s sake at some point is make a bootable disk installer for your OS, but perhaps we’ll go into that another time.

Do you have any tips from the last time you had to recover your Mac? Share them in the comments below.

Photo source: DVIDSHUB