Method and apparatus for data backup and recovery

A computer program product for data backup comprising:

• data storage having stored thereon said computer program, said computer program comprising:
• first program code suitable to operate a processor to receive one or more I/O (input/output) requests;
• second program code suitable to operate said processor to exchange information with a first data storage device according to said I/O requests, including storing some of said information on one or more data blocks of said first data storage device;
• third program code suitable to operate said processor to set an entry in a runtime bitmap to a first value for each of said one or more data blocks, said runtime bitmap having an entry corresponding each of a plurality of data blocks which comprise said first data storage device;
• and
• fourth program code suitable to operate said processor to copy information contained in its corresponding data block in said first data storage device to a second data storage device, for each entry in said runtime bitmap being set to said first value, said fourth program code including clearing said each entry, said fourth program code operating asynchronously with respect to said second program code.

A method for data backup and recovery in a personal computer (PC) comprising:

• determining whether an internal disk drive is available, said internal disk drive having a bitmap stored thereon;
• determining whether a remote disk drive is available, said remote disk drive having a bitmap stored thereon;
• if said internal disk drive and said remote disk drive are available, then:
• accessing first information from said internal disk drive;
• if said first information is indicative of a first mode, then setting a status to indicate a first state of operation;
• if said first information is indicative of a second mode, then setting said status to indicate a second state of operation;
• and
• if said first information cannot be accessed from said internal disk drive, then setting all entries in said bitmap stored on said remote disk drive to a first state and setting said status to indicate said second state of operation;
• if said internal disk drive is available and said remote disk drive is not available, then:
• accessing first information from said internal disk drive;
• if said first information is indicative of a first mode, then setting a status to indicate a third state of operation;
• and
• if said first information is indicative of said second mode or if said first information cannot be accessed from said internal disk, then halting operation of said PC;
• and
• if said remote disk drive is available and said internal disk drive is not available, then setting said status to a indicate a fourth state of operation,
• wherein said bitmap of said internal disk drive or said bitmap of said remote disk drive is loaded as a runtime bitmap into a memory of said PC, depending on said status,
• wherein entries in said runtime bitmap are set to a first value during write operations,
• wherein data blocks are copied between said internal disk drive and said remote disk drive based on contents of said runtime bitmap and on said status, thereby effecting backup and recovery of data.