Online system checkpoint recovery orchestration

1. A method comprising:

receiving at a platform module, a request to recover a system management module process from a checkpoint;

updating the system management module initialization parameter file by setting a flag to start from the checkpoint;

starting a new system management module process with the updated initialization parameter;

loading a checkpoint copy of system management module repository;

recovering volumes from checkpoint snapshots before any data path module activation;

activating data modules with checkpoint metadata offset information and reformatting data module journals;

activating control modules with recovered volume configuration and reformatting control module journals;

setting defragmentation mode to rollback mode and deleting data on checkpoint stripes that were written after checkpoint creation and waiting for defragmentation rollback to complete;

setting host Input Output (IO) direction to checkpoint stripes;

activating routing modules and allowing host IO operations; and

upon successful system activation, marking checkpoint recovery complete and resetting the flag in the platform.

2. The method of claim 1 wherein said updating the system management module initialization parameter file by setting a flag to start from checkpoint further comprises determining whether a system management module process is currently running.

3. The method of claim 2 further comprising when a system management module process is currently running, then terminating the running system management module process.

4. The method of claim 1 wherein said loading checkpoint copy of system management module repository further comprises loading system management module metadata first.

5. The method of claim 4 wherein said loading a checkpoint copy of system management module repository further comprises loading a checkpoint system management module management object database data base and reconstructing in memory object database based on checkpoint.

6. The method of claim 5 wherein said loading a checkpoint copy of a system management module repository further comprises reformatting journal chunks and discarding left over journals after checkpoint generation.

7. The method of claim 6 wherein said loading checkpoint copy of system management module repository further comprises mounting on-disk RAID 1.3 section and dumping in-memory system management module repository to default RAID1.3 location.

8. The method of claim 1 wherein said activating data modules with checkpoint offset information and reformatting data module journals further comprises using said data module to recover harvested metadata/physical layout metadata and user data from hardened checkpoint copy in normal data stripes.

9. The method of claim 8 further comprising waiting for harvested meta data recovery to complete.

10. The method of claim 8 wherein said activating control modules with recovered volume configuration and reformatting control module journals further comprises using said control module to load hash backup metadata based on recovered data module data content.

11. The method of claim 10 further comprising using said control module to reconstruct an address to hash mapping table in memory hash tree and dirty tree for recovered volumes.

12. A system comprising:

a processor; and

memory storing computer program code that when executed on the processor causes the processor to operate a storage system, the storage system operable to perform the operations of:

receiving at a platform module, a request to recover a system management module process from a checkpoint;

updating the system management module initialization parameter file by setting a flag to start from the checkpoint;

starting a new system management module process with the updated initialization parameter;

loading a checkpoint copy of system management module repository;

recovering volumes from checkpoint snapshots before any data path module activation;

activating data modules with checkpoint metadata offset information and reformatting data module journals;

activating control modules with recovered volume configuration and reformatting control module journals;

setting defragmentation mode to rollback mode and deleting data on checkpoint stripes that were written after checkpoint creation and waiting for defragmentation rollback to complete;

setting host Input Output (IO) direction to checkpoint stripes;

activating routing modules and allowing host IO operations; and

upon successful system activation, marking checkpoint recovery complete and resetting the flag in the platform.

13. The system of claim 12 wherein said updating the system management module initialization parameter file by setting a flag to start from checkpoint further comprises:

determining whether a system management module process is currently running;

when a system management module process is currently running, then terminating the running system management module process; and

when a system management module process is currently running, then starting a new system management module process with an updated initialization parameter.

14. The system of claim 12 wherein said loading checkpoint copy of system management module repository further comprises:

loading system management module metadata first;

loading a checkpoint system management module management object database data base and reconstructing in memory object database based on checkpoint;

reformatting journal chunks and discarding left over journals after checkpoint generation; and

mounting on-disk RAID 1.3 section and dumping in-memory system management module repository to default RAID 1.3 location.

15. The system of claim 12 wherein said activating data modules with checkpoint offset information and reformatting data module journals further comprises:

using said data module to recover harvested metadata/physical layout metadata and user data from hardened checkpoint copy in normal data stripes; and

waiting for harvested meta data recovery to complete.

16. The system of claim 12 wherein said activating control modules with recovered volume configuration and reformatting control module journals further comprises using said control module to load hash backup metadata based on recovered data module data content.

17. The system of claim 16 further comprising using said control module to reconstruct an address to hash mapping table in memory hash tree and dirty tree for recovered volumes.

18. A computer program product including a non-transitory computer readable storage medium having computer program code encoded thereon that when executed on a processor of a computer causes the computer to operate a storage system, the computer program product comprising:

computer program code for receiving at a platform module, a request to recover a system management module process from a checkpoint;

computer program code for updating the system management module initialization parameter file by setting a flag to start from the checkpoint;

computer program code for starting a new system management module process with the updated initialization parameter;

computer program code for loading a checkpoint copy of system management module repository;

computer program code for recovering volumes from checkpoint snapshots before any data path module activation;

computer program code for activating data modules with checkpoint metadata offset information and reformatting data module journals;

computer program code for activating control modules with recovered volume configuration and reformatting control module journals;

computer program code for setting defragmentation mode to rollback mode and deleting data on checkpoint stripes that were written after checkpoint creation and waiting for defragmentation rollback to complete;

computer program code for setting host Input Output (IO) direction to checkpoint stripes;

computer program code for activating routing modules and allowing host IO operations; and

computer program code for upon successful system activation, marking checkpoint recovery complete and resetting the flag in the platform.

19. The computer program product of claim 18 further comprising:

computer program code for determining whether a system management module process is currently running;

computer program code for when a system management module process is currently running, then terminating the running system management module process; and

computer program code for when a system management module process is currently running, then starting a new system management module process with an updated initialization parameter;

computer program code for loading system management module metadata first;

computer program code for loading a checkpoint system management module management object database data base and reconstructing in memory object database based on checkpoint;

computer program code for reformatting journal chunks and discarding left over journals after checkpoint generation; and

computer program code for mounting on-disk RAID 1.3 section and dumping in-memory system management module repository to default RAID1.3 location.

20. The computer program product of claim 18 further comprising:

computer program code for using said data module to recover harvested metadata/physical layout metadata and user data from hardened checkpoint copy in normal data stripes;

computer program code for waiting for harvested meta data recovery to complete;

computer program code for using said control module to load hash backup metadata based on recovered data module data content; and

computer program code for using said control module to reconstruct an address to hash mapping table in memory hash tree and dirty tree for recovered volumes.