A Weekend with a Crashed Mac

If you think your Mac OS X is as solid as a building brick, you are wrong. Something shit can happen that causes OS X fail to load.

I got this crash experience recently with my OS X. As technical spec, I have MacBook Core 2 Duo 2.0Ghz, DDR 1.5 GB, HDD 80 GB, with OS X Leopard 10.5.2 before crash. The initial cause of problem was my Macbook battery not detected anymore. Then in some bright days the power adapter had got unplugged accidentally, so the Mac OS got to sudden shutdown. This happened several times, so in one day I tried to do Verify Disk via Disk Utility. It told me some errors. Then when the 10.5.3 update was released by Apple, I downloaded it and tried to install the update in high hope that it can fix my problem. Totally wrong! The update only went half of the way just to say something error to update my root folder. Then it freezed, Finder couldn't be used at all. Then I pressed the magic power button for a while to force it to shutdown. And here was the situation: OS X would not load anymore. It booted, shown Apple logo, dark screen, and restarted, kept restarting.

In short, I could not load OS X into graphical screen at all. Inserting OEM Leopard disk, boot again from DVD, it didn't give me install option that I wanted: "Archive and Install" (so data files can be left untouched). It only gave me option to "New Install". So my only way was to backup my data then wipe of all harddisk to perform clean "New Install".

How to backup a crashed Mac, an unable to boot Mac OS X?

Then how can I backup my data if Mac OS X couldn't be loaded? Here is the tricky job. After digging some information, I just found that we can

• Use Disk Image in Disk Utility to create dmg file
• Use Terminal window to backup data to External Harddisk

I worried about Disk Image, so my choice was to use Terminal and backup all my data file to external harddisk.
1. Boot from DVD. (How to choose boot options in MacBook? Press Option/Alt button while pressing Power On button from MacBook, just hold the Option button even until you hear chimes sound)
2. Wait until OS X Welcome screen.
3. Notice that you have menu bar on top of screen, select Utilities - Disk Utilities
4. Plug External Hardddisk to USB Port, then wait until it is displayed in Device list.
5. Now, open Terminal again from menu bar, select Utilities - Terminal
6. Terminal window is open.

Now, you need to know where your external Hdd mount point path is.

cd /Volumes
ls -l

You'll see list of devices including your OS X mount point. Assuming my OS X mount point name is "Alist Mac" and my External Harddisk name is "Alist HDD" then I can copy file between "/Volumes/Alist Mac" and "/Volumes/Alist HDD". Remember that your home folder (and documents) should be reside in "/Volumes/Alist Mac/Users/UserName/".

To copy file and directories, you just use copy command. Use copy -R to copy directory and its subtree. See this example:

cd /Volumes/Alist Mac/Users/Alist/Documents.
copy -R myData /Volumes/Alist HDD

Easy? Nope. Your external HDD is usually formated using FAT system, while Mac OS X is HFS format. FAT System only allows a file at maximum size 4GB. If you are using Parallel Desktop, then you are doom. Your Parallels Image file is probably larger than 4GB. Check its size (my example file at /Volumes/Alist Mac/Users/Alist/Documents/Parallels/WinXP/winxp.hdd ). This hdd file is actually a directory with a collection of files, but is recognized by Mac OS and Windows as single file.

Then you need to know 2 useful command: split and cat. Split is to split a file into smaller files, and cat is to merge them back.

cd /Volumes/Alist Mac/Users/Alist/Documents/Parallels/WinXP
split -b 1024m winxp.hdd winxp-small-

Above example will split winxp.hdd file into 1GB per file, new file name will be winxp-small-aa, winxp-small-ab, winxp-small-ac, etc. After split the file, you can copy each file to external harddisk. After installing new OS X later, you can copy back to your original location and merge them back using cat command.

cat file1 file2 file3 > newfile

Here is some important preference and data folder to backup in mac OS X

• ./User/Library/Mail
• ./User/Library/Mail Download
• ./User/Library/Application Support/Firefox
• ./User/Library/Application Support/AddressBook

After successfully backup my data, I got peace in mind to format my macbook and perform clean install again. Certainly, not all configuration was brought back, but the most important thing is all my Documents and Mail Inbox was back.

Whollaa.. prepare your whole weekend with this backup and install activity!

If you find my article useful, just drop me a comment below. Enjoy.