Q: yosemite backup to external disk permissions issues
Besides using TimeMachine, always, as an extra precaution, I make a quarterly backup of my Mac HD on an external USB drive, which I store off-site.
I've been doing this for quite a few years, and it seems it has been getting harder over time, due to permissions problems.
Procedure: I set Energy Saver to "Never Sleep" and I drag a bunch of top-level folders over to an recently-erased, mounted, USB drive on the desktop. The Finder copy totes up the number of files, and estimates the time to completion -- typically on the order of 5 hours. Once I see this, I walk away -- or go to bed.
More and more frequently I come back to find some error has aborted the copy. A single file is cited: I don't have permission to copy that file.
My questions:
1. Is there any way fix the problem and continue the copy, or --to be assured that I have a full backup-- must I then re-erase the target drive and run the entire copy again?
2. In the few cases I can recall, checking File Info I seem to have read access to the cited file. Why is that not sufficient to make a copy?
3. Is there a way to preview the copy so I can find out about the eventual permissions problems and fix them before I start a multi-hour process?
4. Is there an alternative to using a Finder copy that is more robust, or at least more resistant to permissions issues? How about running a shell script as superuser, using sudo and ditto, maybe?
5. Any other issues I should be aware of? Special considerations regarding some standard folders, e.g. Applications? I assume I need not backup the Library or System folders, correct?
TIA
iMac, OS X Yosemite (10.10.2), iMac 27-inch Late 2009, ext. displ
Posted on Aug 9, 2015 1:06 PM