Happen to run CentOS myself ... so the specifics below I have done/experienced first hand:
The .log files are ascii/text. One can open using nano or just cat 'em:
nano some.log file
cat some.log file
Can't tell you specifically what you'll find ... but they will be clues. From the looks of the number/size/dates, could be a specific course that is having issues.
Those two files at the top of your screen shot ... how large are they?
ls -l output please (shows size)
Can do a quick peak at the file type:
should show if it's a zip ... in Moodle-ese a .mbz file ... that might fall into that category of too large for CentOS to use the 'copy' command to move them to your /mnt/win/dir.
CentOS 5.x and 6.x as well has an issue with copying files over 4.+ Gig's. An OS bug that's not been fixed yet, BTW. (so it's not Moodle code)
Could do the following in that directory.
mv 71[tab key] ./work
If file 71... above said it was a Zip, unzip it:
Open the extracted moodle_backup.xml with nano OR use head for the top 50 lines:
head -n 50 moodle_backup.xml
That will show the humanly recognizable name Moodle would have used and give you a clue as to which course to explore in the Moodle UI.
Once one knows the humanly recognizable name Moodle would have used for the filename to use in the autobackups designated directory, you could *move* it yourself.
mv 71[tab key] [humanly recognizable file name].mbz
then mv [humanly recognizable file name].mbz again to your /mnt/win/directory:
mv [humanly recognizable file name].mbz /mnt/win/[directory]
Now if that 71[tabkey] file doesn't unzip, or the unzip command complains about an in-complete archive, then we've some more sluthing to do.
At any rate, once you've manually moved .mbz's to your /mnt/win/dir all files and folders could be removed from moodledata/temp/backup/ Don't delete the 'backup' directory, just it's contents. cd moodledata/temp/backup/ [enter] then rm -fR *
Then run your command line autobackup.php script to see what happens.
In one terminal session cd /pathto/moodledata/temp/backup use 'watch ls -lR".
in another terminal session logged on as root user cd /pathto/moodlecode/admin/cli/ run
Also, check those log files to see if it's an issue with a mod/block not compatible with your current version of Moodle being used in 'troubled courses'. If those mods/blocks not all that important one could remove them from the system and especially in the courses that used them.
'spirit of sharing', Ken