Booting From An External Drive

[Smallwheels]

I've got an external hard drive with three partitions. One of them is a Carbon Copy Clone of my hard drive. How do I boot from it? I've made it as a bootable backup but haven't tested it.

I suppose the external hard drive must be switched on before turning on the computer. That makes sense. What do I need to press on the Mac Book to get it working? Is there something I need to do in the System Preferences first?

There are several drive choices in the Startup Disk section. Do I just set this one time and from then on it will select that source until I change it?

What if it doesn't work? Will I be able to get back to starting from the internal hard drive? I would hate to be stuck without a working Apple computer.

Thanks for the help.

Smallwheels

[zedtvl]

Once your external drive is on you can also go to system preference then start up disk and select your drive...
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Mac Mini i5 2.5 GHZ, 16GB Ram.
Macbook pro 2008 Core 2 Duo, 256GB SSD, 2.5GHz, 6GB Ram
Dead PowerBook 180, M4440 33 MHz, 8 MB ram.

[Bandit Bill]

[Smallwheels]

Thanks for the help. The duplicate drive did work. One thing I noticed is that all of the programs I used after booting from the external drive required me to update them. Why would that be if the external hard drive is a duplicate?

The next thing I want to do is copy the contents of the external hard drive to the Mac Book's drive so that everything will be more compressed on that drive. The reason for that is to make it run faster. For the last few months the computer has been getting a bit slower. I've even removed about six gigabytes of files from the computer recently. According to the Activity Monitor the 160 GB drive has 54 GB free.

What steps do I need to take to accomplish this task?


Smallwheels

[Bandit Bill]

The programs must have needed an update before you made the clone, or updates became available after you made the clone.

I don't understand what you mean, by everything will be more compressed?

BTW compressing things makes things run slower as the computer needs to decompress the data before using it.

54GB is lots of free space, your computer should be slowing down with that much space available.


If you want to clean things up, run OnyX (free download).

Also run your machine for a while and run Activity Monitor. What is your number of Page ins vs. Page Outs?

[Smallwheels]

I suppose when my computer reloads all of the files on the disc they will be defragmented, thus allowing the files to be accessed faster.

One program that rarely gets updated such as Flip4Mac, was one of the ones that needed the update. The thing is that I had updated it just a week or two before booting from the external hard drive. The other one was Silverlight. I watch movies and TV shows regularly.

I have Onyx and have run it a few times. I've not noticed any speed differences after using it. Maybe it will make a difference this time. I'll check it out later this week.

Smallwheels