Method for operating disk drives in a data storage system

A method for operating a disk drive in a data storage system, comprising:

• continuously polling the disk drive to determine whether such disk drive has placed itself in a by-pass condition;
• if during one poll of such polling a determination indicates such disk drive has placed itself in a by-pass condition, determining whether a disk access inhibitor flag has been set, such set disk access inhibitor flag operating to place the disk drive in an inaccessible condition, and:
• if such disk access inhibitor flag has been set, placing the disk drive in an inaccessible condition for use by the system interface;
• otherwise,
• determining from a mark whether a first predetermined period of time has passed since a prior poll in the polling indicated that the disk drive had placed itself in the by-pass condition;
• and
• if the first predetermined time has passed, waiting a second, shorter predetermined period of time to determine from the polling whether the drive has placed itself in the by-pass condition;
• and
• if the disk drive has placed itself in the by-pass condition, setting the disk access inhibitor flag to maintain the disk drive in the inaccessible condition;
• otherwise,
• generating the mark to indicate a first occurrence of the by-pass condition and recording a time of such mark generation.