The other day I reinstalled OS X. My computer had become extremely sluggish and I wanted to see if the performance would improve if I reformatted my hard disk and started over. Along the way I learned a few lessons about restoring using Arq. Here’s what I did:
Before Wiping Out My Data
Before I went through with it, I made sure I had all my data backed up. Arq had backed up the following:
- ~/Library (excluding Logs and Caches)
- ~/Documents
- ~/Music
- ~/Pictures/iPhoto Library (my photos)
- ~/src (my source code)
- /Applications
- /Library/Application Support
Reinstalling
I inserted the Snow Leopard installation disk, shut down the computer, and then started it holding down the Option key. I clicked on the DVD and the computer booted from it. I formatted the disk and installed OS X. I created a user with the same name as I was using before.
Next I downloaded and installed Arq. I launched Arq and entered the same S3 keys and encryption password I was using before.
Finally it was time to restore using Arq.
Initial Restore
Instead of waiting for absolutely everything to be restored from S3, I restored files in several steps.
Restoring ~/Library
The first step was to restore ~/Library from my “other computer” (the previous incarnation of my computer). I opened the triangle next to “Other Computers”, found my old computer, opened the triangle next to “Library” and selected the latest backup:

Then I clicked “Restore…” and Arq restored the Library folder to ~/Restored by Arq/Library (because a Library folder already existed).
When that restore was done, I closed all open applications, deleted the contents of ~/Library, and dragged everything from ~/Restored by Arq/Library to ~/Library.
Back in Business
At that point I could use Mail, iCal and Address Book. I selected a few applications in Applications backup folder and restored them as well.
I also wanted to sync my calendars with my iPhone, so I plugged it in and it sync’d. Later I’ll delete the iTunes files in ~/Music and replace them with the backed-up files.
Restoring Everything Else
Now that the computer felt “back to normal”, I restored my “src” folder (where all my work files are). Then I got back to work, restoring the really large folders (Documents, Music and Pictures) at my leisure over the next few days.
Conclusions
The multi-step restore approach was a big time-saver and got me up and running fairly quickly. The Library folder was relatively small (really small in fact, with the exception of Mail).
I learned that reformatting the hard drive helped a little with sluggishness, but the long-term fix is likely the purchase of an Optibay and an SSD.
I also learned that restoring this way is fairly complicated. So I’m thinking about how to make a product that would restore more seamlessly while also allowing people to get back to work before absolutely everything is restored. There’ll be more to come on that.