Log All will be a huge part of your Problem. When you have many small Files the MediaAgent collects and sends many Detail Infos to the CellServer and that slows down the whole Process.
You should definively reduce it to Log Files (Only logs Directory and Filenames to IDB, no Modification or Creation Dates) or if you don't need to restore single Files go to Log Directories (only logs Directory Names to IDB)
You didn't mention if it is Windows or Linux, for Windows set up OB2NOTREEWALK=1 in the local omnirc-File.
That will skip the first TreeWalk that calculates how many Objects to back up, on Filershares this alone can take hours.
If you get the not a vaild Mountpoint Message with VBDA your given path is incorrect.
A proper output for a Windows Mount looks something like this:
C:\Program Files\OmniBack\bin>vbda -vol D: -out NUL -profile
[Normal] From: VBDA@host "" Time: 09.10.2014 09:08:56
STARTING Disk Agent for host:D: "".
[Normal] From: VBDA@host "" Time: 09.10.2014 09:11:53
Backup Profile:
Run Time ........... 0:02:57
Backup Speed ....... 90.84 MB/s
[Normal] From: VBDA@host "" Time: 09.10.2014 09:11:53
Filesystem Statistics:
Directories ........ 4501
Regular files ...... 13880
------------------------------
Objects Total ...... 18381
Total Size ......... 15.70 GB
[Normal] From: VBDA@host "" Time: 09.10.2014 09:11:53
COMPLETED Disk Agent for host:D: "".
time: 177 (sec), tot: 0 (kB), done: 0 (%)