Disk array apparatus and method which supports compound raid configurations and spareless hot sparing

A disk drive array system which supports compound configurations, comprising:

• a disk drive array having a first configuration;
• and
• a disk drive array controller coupled to said disk array, comprising:
• disk drive failure detection logic which detects when a drive failure occurs;
• and
• reconfiguration logic coupled to said disk drive failure logic and said disk drive array which reconfigures one or more disk drives in said disk drive array according to a second configuration if said disk drive failure detection logic detects a drive failure;
• wherein said reconfiguration logic reconfigures one or more disk drives in said disk drive array each time after said disk drive failure detection logic detects a drive failure for a plurality of times.

A method for supporting compound configurations in a disk array system comprising a disk array including a plurality of disk drives and a disk array controller coupled to the disk array, the method comprising the steps of:

• configuring the disk array according to a first configuration;
• the disk array controller determining if a disk drive failure has occurred, wherein one or more of the drives comprising said drive array remain functioning properly after said disk drive failure;
• and.
• the disk array controller automatically reconfiguring one or more of the one or more functioning drives comprising said drive array into a configuration having less redundancy than said first configuration if a disk drive failure is determined to have occurred in said step of determining;
• and
• the disk controller repeatedly performing said steps of determining and reconfiguring for a plurality of disk drive failures.

A method for supporting compound configurations in a disk array system comprising a disk array including a plurality of disk drives and a disk array controller coupled to the disk array, the method comprising the steps of:

• configuring the disk array according to a first configuration, wherein said first configuration comprises a full RAID 1 configuration and said plurality of drives comprising said array are configured as mirrored pairs;
• determining that a first disk drive failure has occurred, wherein said disk drive failure involves a disk drive in one of said mirrored pairs;
• and
• reconfiguring one or more of the drives comprising said drive array into a second configuration in response to said first disk drive failure, wherein said step of reconfiguring comprises combining the remaining disk drive from said mirrored pair where said disk drive failure occurred with another mirrored pair to form a three drive set using said second configuration.

A method for supporting compound configurations in a disk array system comprising a disk array including a plurality of disk drives and a disk array controller coupled to the disk array, the method comprising the steps of:

• configuring the disk array according to a first configuration;
• determining if a first disk drive failure has occurred;
• reconfiguring one or more of the drives comprising said drive array into a second configuration if a first disk drive failure is determined to have occurred in said step of determining;
• determining if a second disk drive failure has occurred;
• and
• reconfiguring one or more of the drives comprising said drive array into a third configuration if a second disk drive failure was determined to have occurred in said step of second disk drive failure determining.