No bad-sector mapping
HCL Informix® relies on the operating system of your host computer for bad-sector mapping. The database server learns of a bad sector or a bad track when it receives a failure return code from a system call. When this situation occurs, the database server retries the access several times to ensure that the condition is not spurious. If the condition is confirmed, the database server marks as down the chunk where the read or write was attempted.
The database server cannot take any action to identify the bad cylinder, track, or sector location because the only information available is the byte displacement within the chunk where the I/O operation was attempted.
If the database server detects an I/O error on a chunk that is not mirrored, it marks the chunk as down. If the down chunk contains logical-log files, the physical log, or the root dbspace, the database server immediately initiates a stop action. Otherwise, the database server can continue to operate, but applications cannot access the down chunk until its dbspace is restored.