Originally Posted by grimpow
So I'm pretty sure I know the difference between clean and dirty flashing (for a clean flash you wipe /system and /data, for a dirty flash you wipe nothing, maybe cache and dalvik). But my question is, how do I know which one to use and when? Is dirty flashing only for updates to your current ROM, and nothing else? Specifically with the unofficial Cyanfox KitKat ROM, can I just dirty flash each nightly?
For example: if you are on CyanongenMod11 Nightly and want to flash to the next CM11 Nightly most of the time a dirty flash is acceptable
However: From CM10 to CM11 (or two completely different roms) a dirty flash would result in bootloops/FC's/ect... a full wipe would be required
If you are staying on the same rom and just flashing a new release of that rom (version increment) as long as the OS doesnt change (ex. android 4.2.2 to 4.4.2) most of the time a dirty flash is sufficient unless stated by the Dev of that rom.
But to minimize errors Full wipes are generally a good idea (that way no data gets left behind that would cause issues)