I doubt, it overwrites previous autosave, one of my latest autosave couldn't open and I got missing DNA block error (probably due to sudden powercut or crash),but I also couldn't see it's five minutes earlier backup, I mean if latest autosave wasn't complete why wouldn't I be able to see it's previous backup chronologically,instead i am seeing backups as per sessions.
Heya. This should only happen if you set the "Max Backups Per File" user preference to 1. The default is 10. It could also be that your "Save Interval" is too high, as the hard maximum on it is 120, so one save every 2 hours. But the default is every 5 minutes.
Another thing to note is that on Linux, if you use the system /tmp/ folder, it gets wiped when the system is restarted.
But other than that, I'm not sure what the issue could be, as I'm working on a file right now and my backups are being created exactly as configured. If it's not working for you, please submit a bug report here.
Incremental Auto-Save
I doubt, it overwrites previous autosave, one of my latest autosave couldn't open and I got missing DNA block error (probably due to sudden powercut or crash),but I also couldn't see it's five minutes earlier backup, I mean if latest autosave wasn't complete why wouldn't I be able to see it's previous backup chronologically,instead i am seeing backups as per sessions.