is it possible to keep a boot-able backup drive clone of OS X updated with rsync? If rsync is not a viable option are there alternatives?
My situation is as shown above. One internal Samsung 840 SSD [120g] in use as my OS X 10.8 boot disk on a recent model Mac Mini. I have successfully cloned that drive with disk utility to a 125g partition of another HDD in an external USB 3 enclosure and at that point I am able to boot to it.
As my last system went out in a fiery blaze taking much valuable data with it, I have a new respect for a proper backup solution and really want to do this right. My goal is to achieve an automated differential backup/update from Disk A to Disk B while most importantly maintaining boot-ability on the external drive. And I would prefer to do this differentially to minimize stress on the drives. Hence rsync was the first thing to come to mind.
What I have tried:
running this manually initially worked - i tested it with only very miniscule file change and everything was fine / external booted and all. now after subsequent passes rsync fails throwing errors particularly relating to updating 'boot.efi' (not at the machine currently I will update the precise log message once I return home)
is this a drive partition size issue? does rsync require more space?
if it cant be done, are there any alternatives? i've heard whispers of dd
EDIT: (for additional information)
- OS X 10.8.4
- 2.3 GHz Intel Core i7
Disk A is a 120gig capacity SDD with again only about 35 gigs in use.
Disk B is a 125g Partition as stated above and only has approx 35g in use with another ~= 90g of space available
was just throwing this out there as i don't precisely know how rsync operates but can't imagine it would utilize more than 125g of 'scratch' space to differentially back up 35 gigs of data and settings.
After a few more hours of inability to recreate the issue and failure to successfully operate i stumbled upon a few existing software options and have been giving them a try.
Still would like to know the proper way to differentially update a cloned boot drive with rsync and bless if there is someone with a working process.