IMac – Added SSD to mid 2011 27″ iMac. How to keep user accounts on HDD and only use SSD for OS and Apps

In the Mid 2011 iMacs (both 21.5" and 27") Apple left enough room for an extra SSD. So if you want to put an SSD inside your iMac you can do that without replacing the DVD drive and/or original hdd. If you're going for an external one you should indeed opt for a SSD with a Thunderbolt connection, otherwise you kinda loose the speed advantage of a SSD.

If you want to separate the OS and application data from your media files, that's entirely possible and there's more than one way to achieve that. Read this and decide for yourself wether it's easy:

• http://www.tuaw.com/2012/01/20/ask-tuaw-how-do-i-setup-a-mac-with-both-an-ssd-and-a-regular-hd/
• http://mattgemmell.com/2011/06/21/using-os-x-with-an-ssd-plus-hdd-setup/

SSDs will only get better and cheaper over time so it can make sense to wait, but since they'll keep getting better and cheaper you could also wait for the rest of your life but SSDs are becoming mainstream now so it is safe to make the jump.

Remember that if you install a SSD in your iMac yourself you will loose your warranty so it may be worth to let an Apple Authorized Service Provider do the upgrade for you. If you insist on doing it yourself you might find the following link useful:

• http://www.ifixit.com/Guide/Installing-iMac-Intel-21-5-Inch-EMC-2428-Dual-Hard-Drive-Kit/6434/1

Good luck!

Besides the obvious issue of you having too much information to load onto the SSD, I've done this basic procedure in the past. However, it's much easier now using Time Machine, but you have a few options:

Time Machine

If you don't currently have a backup that can hold all your data, do yourself a favor and pick up a drive that can. Time Machine should be built into the OS you're currently running.

Do the backup. For 400 GB, you probably want to set it up before you go to sleep and let it run overnight. Once it's complete, unmount the drive and unplug it from the computer. Go through with the drive install and then install Lion. When the computer reboots, before you start to work with the setup assistant, plug in the new drive. At some point it will prompt you for a location from which to migrate data. Select your backup. Let it run for a while and when you get back, it will contain all the data you backed up, in a usable form. This is my current favorite method for cloning user workstations.

Super Duper

If you can't get an external backup, you can use SuperDuper to create a full-system backup from the active system disk. You'll have the ability to trim the data to the size of the disk to which you're copying in the interface. This route is a little more technical and requires a bit more time hands-on.

File Copy

I wouldn't recommend copying a user folder for a logged-in user due to open preferences files. You'll get all kinds of "File In Use" errors and it will probably exit the copy prematurely. Instead (if you're dead-set on using this method - which I advise against) create a second admin user and copy the folder over into a temporary location before staging it into the actual /Users/ location. You'll also need to make sure the permissions for the entire folder are set so that the user whose home you are copying can actually access and write to their files. To do this, you can use the Finder's Get Info on the folder and then add the user to have full permissions. Once it's staged into the /Users/ folder, you can log back in to the main user and delete the secondary admin. You may have permissions issues in the future using this method.

All that said, it's totally worth it to get an external to back up to for Time Machine to clone your new SSD from.