Moving Out


I have a lot of data to move about. The Migration Assistant is great, but sometimes it can’t be used. There is nothing wrong with not using it, but for my purposes it wasn’t happy with me.

As I moved things over, I realized there should be some prep work before copying a home folder over. There isn’t some chanting rain dance that needed to be performed, but some important maintenance areas that should get looked at. If you’re home folder is 200 Gb like mine, this should help out very nicely. Even at 25 Gb, you might find some useful tools here to speed things up. Since Apple is giving PC users the truth about productivity, I thought this would be timely for those of us selling our old Macs to Windows-dumping friends. (Guilty)

Some ground rules when dealing with large amounts of data. First, never empty your trash can until you are done. Even then, hang on to it for a week or two and make sure nothing gets lost because of a common task like trash emptying. Second, close all applications before moving or copying things around. Sometimes an app is doing something and a copy or move command will fail because of application busy work. It will really slow things down if the computer keeps encountering ‘Can’t be copied because it’s busy’. Lastly, gigabit ethernet and target disk mode are great tools. I highly suggest purchasing a gigabit switch/router. Otherwise, you can just run a network cable between the two machines (which Migration Assistant doesn’t deal with) and turn on file sharing or FTP from System Preferences->Sharing. Target Disk mode only works on the primary hard drive, so don’t expect a secondary drive to show up on the new Mac. Results vary depending on the age and firmware of the Mac. Yes switching the cables around changes what drive is mounted, but this seems like the next and better step would be installing the old drive in the new system if possible.

Ok, on to the things to reduce copy times.

1) Caches. OS X stores a lot of information used frequently in caches. This can vary from application to application, but the general practice is to put this stuff in Home/Library/Caches. The debate on caches is viewed as a troubleshooting step as well, but it’s stuff that isn’t needed on a new system. Let OS X do what it does with caches on the new system. It seems Safari, for example, stored 60% of the entire internet in this folder and frankly 59% was stuff I never want to see again. Emptying this stuff can be done from Safari by using the Command-Shift-E combo or from the ‘Safari’ menu next to the pretty Apple in the top left of the screen.

2) Get JDiskReport, which will tell exactly where the largest directories live. Drill through it and clear out anything that seems useless, such as oversized log files or worn out video files =). If you delete stuff you wanted, don’t blame me! You do have a backup, right?

3) Compress the Documents folder if documents are put in it. I know that sounds a bit silly, but I know a lot of people who treat ‘Documents’ like it should be ‘Dumping Ground’. Everyone is entitled to their own workflow style. I’m not here to try and change that. I actually put documents in there, and compressing it with CleanArchiver chopped it down 40% easily.

4) ~/Library/Mail is where all Apple Mail data goes. In 10.4 attachments are going into the folder ‘Mail Downloads’. Aside from emptying the trash within mail, compressing these helped, but the time it took didn’t seem like a benefit to me. Your situation might be different.

5) Permissions. When I set up the Mini, I used a different short name. This caused some weird behaviors at first. Once all the data is back in place, click on the home folder, get info, and apply the permissions to all files. accomplishes the same thing from the command line using ‘sudo chown -R youraccountname:youraccountname ~’ and ‘sudo chmod -R 755 ~’ without the obligatory tick marks. Again, results vary so this is more of a troubleshooting tip than a requirement. If the beach ball shows up when you’re checking things, then it is probably because of permissions.

After all was said, I shaved off 72Gb’s of information. This turned into saving 4 to 5 hours of copying. It’s all scale, so I would be interested in knowing how others faired. Also, what other things might be done to prep migrating a home folder?


Morgan Goeller


If you are really going to be moving a lot of data, I would really recommend going with the UNIX utilities that are built into OS X. From doing some work with backups (in the 1-10GB range), I have found that it is anywhere from 5-10 times faster.

Some hints …

1. To find out what files are where, you can use the du and df commands.
2. To move files you can use the rsync command. This is really nice, as you can set it so that if the file already exists at the target destination only the differences (if any) between the files will be transferred. This can save a ton of time and configuration.

Good luck!


Nice article,

Myself, I am guilty of just saying ‘ah screw it’ and just copying it all overnight or while I’m at work. But I do my regular monthly cleanup so maybe I dont need to do stuff like this :)

JDiskReport is a useful tool! Never heard of it! Probably because of it’s HIDEOUS user interface :p, definitely helps though!

Oh those of us like me who never delete anything that isn’t 100% destined for deletion need a little app something like DoThisNow (, except free. This way we can empty our trash every week(day?) or so without having to constantly ctrl-click! (probably 50% of my alt-clicks are on the trash : ). Now that’s how to stay on top of things! Automation!

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