Restriction on number of devices for backup [CR 542986, CR 541872]

Sybase IQ supports a maximum of 32 hardware devices for backup. For faster backups, specifying one or two devices per core will help to avoid hardware and IO contention. Set the SIZE parameter on the BACKUP command to avoid creating multiple files per backup device and consider the value used in the BLOCK FACTOR clause on the BACKUP command. See Chapter 1, “SQL Statements,” in Reference: Statements and Options.