Created attachment 1272599 [details]
Output of rsnapshot after running it with one lvm backup point and one plain local directory backup point

Description of problem:
I have a backup configuration in which some backup points are lvm based and others are not. In this situation the backup errors out on the first non-lvm backup point after at least one lvm backup point was handled.

Version-Release number of selected component (if applicable):
rsnapshot.noarch 0:1.4.2-2.el6

How reproducible:
Always

Steps to Reproduce:
1. create a backup configuration in which the first backup point is an lvm based backup and the second one is a normal directory backup (or any other backup that's not lvm based). To make the next steps below consistent, also set sync_first to 1

2. do a test run by executing 'rsnapshot -t sync'
3. the same error also happens with a normal run 'rsnapshot sync', but the test run is just faster. 

Actual results:
Observe the commands listed: first the cycle for the lvm backup point is properly described. When the commands for the non-lvm backup point are to be printed, you'll first notice a number of warnings about the use of uninitialized variables and then an error.

Expected results:
Test and full run complete without error

Additional info:
I've traced this back to improperly undefining the two variables at the end of the lvm backup point run instead of resetting them to 0 (their initial state before any backup has run). Other parts of the code expect these variables to exist at all times and only checks whether they are or are not 0 or 1 depending on the situation in which they are tested.

I'll attach the output I get from the faulty rsnapshot script and a patch that fixes the issue for me.