Gail,

We have Informix 7.xx and ON-Bar running on HP-UX and Solaris to both
AIX and HP-UX ADSM servers.  We used standard tuning for the ADSM
client.  Check the IBM Redbook "Using ADSM to Backup Databases"
SG24-4335-02 for alot of good information on ON-Bar.

Quickly, check the BAR_NB_XPORT_COUNT and BAR_XFER_BUF_SIZE vars for
ON-Bar (number buffers and size of buffers for communicating with the
Informix engine). And also BAR_MAX BACKUP for max number of parallel
sessions.

We see anywhere from 10GB-20GB/hour on our HP systems (they are the
largest at about 74GB per instance - 3 instances) across the network.
Speeds should be significantly better to local attached tape devices.
Are ON-Bar and dsmserv getting the CPU cycles and I/O they need?
Sometimes, I have also seen very poor performance when TCP/IP is setup
incorrectly (this is especially true for FDDI cards on RS-6000 machines
no one ever sets the xmit queue size correctly...).

Check the redbook, it has good suggestions.

David Hendrix
dmhendri AT fedex DOT com