This is a discussion on question about Wipe data/dalvik within the HTC Incredible Hacks forums, part of the HTC Incredible Development category; Originally Posted by jpr Whjen using ROM manager to install a new ROM, it asks you if you want to run a backup, and it ...
Now I have a question... It's still about wiping the data and dalvik cache. When installing a new ROM from ROM Manager, it asks if I want to wipe the data/dalvik cache. I'm scared to do anything, because I don't understand what wiping it does. Some some explanation on what wiping the data and dalvik cache would be awesome
A ROM will integrate programs into cache and dalvik cache to enable quicker access to them. Since this process is ROM-dependent, you'll get all sorts of untoward behavior if you leave old stuff in those caches when switching to another ROM.
You will notice that it take much longer to boot a newly installed ROM the first time you fire it up: it is populating those caches; having done that once, the phone will boot faster the next time it is powered on..
Before making any changes, you should be making a nandroid backup. Those include cache directories. You needn't be scared to do anything after that, since you can always go back to a prior state by restoring its backup.