[Update: I used the Ars Technica: How to make your own bootable OS X 10.9 Mavericks USB install drive instructions to create a MacOSX 10.10 Yosemite Install USB Drive, and also created a bootable USB drive with utilities as below. On the 32GB USB drive that I use, I set the installer partition at 10GB and use the rest for the Utility partition using Disk Utility before running the Diskmaker X utility, a minimum size is probably more like 8GB–such as using an 8GB USB drive. The upside to the smaller partition is that it gives you enough free space to update the Utility OS with a newer version of the OS if needed.]
[Update: I used the Ars Technica: How to make your own bootable OS X 10.9 Mavericks USB install drive instructions to create a MacOSX 10.9 Install USB Drive, and also created a bootable USB drive with utilities as below.]
[Update: These are the same instructions I used for a 10.8.x Bootable USB Drive. Remember the InstallESD.dmg is in the downloaded Installer and isn’t available from the created Install partition, so I put a copy of this in the Utility drive’s download folder.]
With Mac OS X 10.7 coming as a digital download (and hence no install DVD), it seemed like as good a time as any to try making a bootable USB drive to use in case of emergency. So a full bootable copy of OS X, with it’s normal utilities, plus space for additional tools for utilities like Drive Genius and Data Rescue.
Here’s how I did it.
- Get a USB Drive. I ended up going with a 32GB drive–a full OS install takes 14+GB, plus space for extra utilties and the OS installer is described as being 4GB but it’s really a bit larger.
I used a Transcend JetFlash 600 – 32 GB USB 2.0 Flash Drive TS32GJF600 (Black). As of mid-2011 it’s supposed to be one of the faster USB 2.0 drives. [Update: I now recommend: Lexar JumpDrive Triton 32GB USB 3.0 Flash Drive LJDNV32GCRBNA. The USB 3.0 makes a world of difference is speed!]
- Partition and Format the drive. I formatted the drive using Disk Utility as Mac OS X Extended (Journaled) and with a “GUID Partition Table”. I partitioned the drive into two partitions–the first for ~28GB for the bootable OS (Utility) and the other at 4.7GB for the installer (Install). My theory on the Installer sizing being that amount should be large enough to future-proof that partition for newer DVD-sized OS installers.
- Create the OS X Installer on the Install partition. I basically followed the instructions from OSX Daily page: Make a Bootable Mac OS X 10.7 Lion Installer from a USB Flash Drive. (Though About.com has a nice set of instructions as well.) I had a copy of the Lion installer, mounted the ESD disk image and then restored it to the USB drive install partition. I did this step next, just in case the restore decided to reformat and repartition the entire USB drive–thankfully it didn’t. I also locked the installer (“Get Info”) since Lion apparently has a habit of deleting itself after it runs.
- Install OS X onto the Utility partition. I booted the computer from the newly created install partition (yay it worked!) to install the OS on the other partition. This started fine–with about 15-20 minutes to create the updated installer and then an hour and twenty minutes to do the install. For some reason, the install seemed to hang with about 6 minutes (40%) remaining and stayed there for as long as an hour.
- Boot from the Utility partition. The computer restarted from the Utility partition and completed the install.
- Copy over and install various additional utilities. Viola that’s it!
So it all went pretty well. I spent about an hour or so doing research on the best way to do this and getting things prepped. The OS install took about an hour and a half. And then probably another 30-45 minutes to finish installing software on the drive.
A note: The USB drive should be faster and more convenient that using an install DVD.
However, it’s not the zippiest of drives (in other words like a hard drive) that you can use to boot your Mac. Also, it seems that it only likes to run (or focus on) one app at a time. Trying to multi-task makes me feel like I’m sitting through molasses. (Them thar USB 3.0 drives are pretty zippy!)