we run baan4 with oracle 10.1.0.4 on linux-platform,
sa few sessions (archiving, big updates) abort with ora-1555
"rollback segment with number 4 "_syssmu4" too small

we have undo managment on, undotbs is 6 GB,
actual portingset for linux.

thanks for any hints

your undo_retention needs to be longer than your longest transaction.

Dave