run dbcc first on database before dump
i think that you need to extend your data , log devices with 10% over, because ase15 devices has extra size.
solution2- migration using devices:
i applied that approach when migrating ase12.5 to ase15- try it
1-Quiesce the database to a manifest file
quiesce database for_upgrd hold testdb
for external: dump to “d:\data\db_manifest.mfst” with override
2-Copy the devices using disk copy commands, or file explorer to the new destinatin.
3- When the device copy is finished, release the quiesce by a SQL statement similar to:
quiesce database for_upgrd release
4- If this is the final upgrade , shutdown old ASE to prevent further changes.
5- Move the device copies to the new host machine and mount them using mount command(for more detail see ref manual).
I suggest reading technical note from sybase , published in Mar 27, 2006 , title:
"Urgent from Sybase: Possible data integrity issue when loading a database from a dump, affecting versions of Adaptive Server Enterprise 15.0, 12.5, and earlier"
at url: http://www.sybase.com/detail?id=1039810