I have a D: drive with two top-level folders. I only want to back up one of them.
When I configure my backup, I specify the "File level backup (slower)" mode.
When I get to the part where I select the files, I've noticed that depending on how I interact with the UI, I can get the note next to "Local Disk (D:)" to say "> volume level backup" or "> file level backup (slower)".
I just ran a test where I tried each approach on a 3 GB folder tree with lots of folders and a mix of file sizes. To keep things fair, each test backup was performed after I deleted all the .vbk and .vib files.
Anyway, the performance difference was huge:
-- File Level: Data is read at 27 MB/s, entire backup takes 2 min 46 sec
-- Volume Level: Data is read at 282 MB/s, entire backup takes 0 min 48 sec
Is it safe to use Volume Level backups on partial volumes in this manner? Is there any downside?