sybase dump error

I am having a serious challenge and I urgently need help.
below is the error i had while taking dump from one of my server.

Backup Server: 6.58.1.1: Device '/dev/rmt3.1' supports multiple dump files per v
olume set.
Backup Server: 7.4.2.1: Option 'CAPACITY': '-400293888' is an invalid value -- c
heck the documentation for allowable values.
Msg 8009, Level 16, State 1:
Server 'YYYYDB', Line 1:
Error encountered by Backup Server. Please refer to Backup Server messages for
details.

Please help me out.

Thank you