If you use auditing on your Adaptive Server, the auditing system performs frequent I/O to the sysaudits table in the sybsecurity database. If your applications perform a significant amount of auditing, place sybsecurity on a disk that is not used for tables where fast response time is critical. Placing sybsecurity on its own device is optimal.
Also, use the threshold manager to monitor its free space to avoid suspending user transactions if the audit database fills up.