What is your company policy ?
Use raw devices or file system for the data and log of SAP/Sybase ASE dataserver ?
Raw devices give full control to ASE for writes (transaction commits) done by ASE engine rather than by underlying OS as in case of file system devices.
Normally using a block device is most probably a typo type of mistake by the DBA who created it.
He/She may have forgotten to correctly use the raw device name required "r"
(e.g. /dev/data01 rather than /dev/rdata01 )
If the device is not used you can drop and recreate it as a proper raw device.
HTH
Avinash