save set size does not match

Dear All,

Below is my setup:

Legato Networker Version 7.3.0.2

Backup Server OS- Windows 2003 Enterprise

Clients:-

a- Sun server with Solaris 9 (high priority server with the source codes)
b- Netapps FAS940 ( has a storage tek L40 library directly connected to it just for NAS backup ¿ NDMP )
c- Quantum P4000 library connected to backup server with SDLT drives (6 nos ; 170 slots)
d- 10 more clients (a mix of linux and windows)
e- Out of the above 10 one is the exchange server ; only mailbox backup is taken.

and my Full backup ¿ approx 25 SDLT2 tapes.

Problem: The save set size does not match (the size before and after backup does not match)


Thanks & Regards,

Sandeep