Moodledata's subdirectory that can be skiped for a whole backup?

Hi,

I would just like to be sure about moodedata's subdirectories that can be skipped when doing a whole site backup (for history, migration on another server...) ?

I think about cache, sessions, temp and trashdir.

Not saving them will just mean that users will have to connect again, caches to be populated again, but the site should be OK?

Thanks
Séverin