'Best practices' question for a backup

[Madison Kelly]

Hi all,

   I've run into an ethical/best practices question that I wanted input 
from as many people as I could get on. I have a backup program that is 
aimed to be generally available to the public. That said, I need to be 
careful how I tell the program to work. In this case though, either 
decision I think could upset someone. So....

   The problem is; when a file or directory has the permissions set to 
not be world/group readable the backup program (well, 'rsync' 
specifically) will fail to backup that file.

   I have two options (as I see it, is there a third?):

   1. Leave the file behind and assume that the user knew what s/he was 
doing.

-OR-

   2. Have my program temporarily raise the permissions to allow for the 
file to be backed up and then reset them after words.

   If I choose number 2 I will be compromising the user's settings but I 
will also be getting their data off (presumably) to a safe place. The 
biggest risk is the program dieing or being killed before it can restore 
the permissions on the modified files (which would have to wait until 
after 'rsync' finishes which could be a big window).

   If I choose 1 then I need to educate the user (or just assume the 
user knows what s/he is doing) and risk missing potentially important 
files in a backup.

   So what is better? Risk missing files in a backup job or risk messing 
up a user's permissions? It's a tough one...

Madison
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