So both my hard drives are 500GB in size yet my backup drive has 20GB more space available than my internal drive. The internal is an SSD whereas the external in an HDD but I doubt that makes a difference. I use CCC to clone my drive and if I'm doing it right (which I believe I am) than both drives should have the same space available right?? Anyone know why I'd have that much difference in space?
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About 20GB difference between internal and backup HDD
- Thread starter bigpoppamac31
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The drive clone programs such as CCC or SuperDuper do not copy cache files and some other files - they have an internal list of files that do not need to be copied. I use SuperDuper and have done a clone then booted from the clone and all is well.
Yes, always test your clone! Better safe in between than sorry when depending on your backup!
You internal Mac OS X partition has a sleep image file which is the same size as your RAM, i.e if you have 16 GB of RAM, the sleep image file takes ~16GB of space.
CCC and other backup softwares do NOT copy this (empty) file (+ some cache files), therefore the backup drive has always more free space than your internal drive.
As said above, it is important to check that your clone is bootable and fully functional.
(the sleep image is used to copy the RAM content when the computer goes to hibernation mode)
Better yet make multiple clones! I have 4 per machine which I rotate, so I always have a backup point. 1 clone I store in a fireproof box... It also helps if you do a software update or add a new program and things get really messed up.