Reaching a normal operating mode via a fastboot procedure

1. In a data storage system, a method of reaching a normal operating mode in which the data storage system performs data storage operations in response to data storage requests from a set of external host computers, the method comprising:

performing a full-boot procedure which includes a set of critical boot activities and a set of avoidable boot activities;

in response to completion of the full-boot procedure, providing a fastboot notification indicating to the data storage system that a fastboot procedure is to be performed in response to a warm boot event; and

after providing the fastboot notification, placing the data storage system into the normal operating mode in which the data storage system performs the data storage operations in response to the data storage requests from the set of external host computers;

wherein performing the full-boot procedure and providing the fastboot notification occur while the data storage system operates in a booting mode in which the data storage system does not yet perform the data storage operations in response to the data storage requests from the set external host computers; and

wherein placing the data storage system into the normal operating mode includes transitioning the data storage system from operating in the booting mode to operating in the normal operating mode.

2. A method as in claim 1 wherein providing the fastboot notification indicating to the data storage system that the fastboot procedure is to be performed in response to the warm boot event includes:

setting a fastboot flag in memory of the data storage system to an asserted state.

3. A method as in claim 2 wherein the memory of the data storage system includes a memory device that is accessible by processing circuitry of the data storage system while the data storage system is in the booting mode; and

wherein the method further comprises:

detecting, by the processing circuitry, the warm boot event which transitions the data storage system from operating in the normal operating mode to operating in the booting mode,

in response to the warm boot event and while the data storage system is in the booting mode, reading, by the processing circuitry, the fastboot flag from a location in the memory device, and

performing, by the processing circuitry, a boot process which includes (i) the full-boot procedure if the fastboot flag is set to a de-asserted state, and (ii) the fastboot procedure rather than the full-boot procedure if the fastboot flag is set to the asserted state.

4. A method as in claim 3 wherein the fastboot flag that is read from the location in the memory device is set to the asserted state; and

wherein performing the boot process includes performing the fastboot procedure rather than the full-boot procedure in response to the fastboot flag being set to the asserted state.

5. A method as in claim 4 wherein performing the fastboot procedure includes:

setting the fastboot flag in the memory device to the de-asserted state, and

after the fastboot flag is set to the de-asserted state, performing the set of critical boot activities.

6. A method as in claim 5 , further comprising:

after the fastboot flag is set to the de-asserted state and in response to the set of critical boot activities completing successfully, re-setting the fastboot flag in the location in the memory device back to the asserted state, and

transitioning the data storage system from operating in the booting mode back to operating in the normal operating mode in which the data storage system performs the data storage operations in response to the data storage requests from the set of external host computers.

7. A method as in claim 5 wherein the memory device is a non-volatile random-access memory (NVRAM) device which, in the location, persistently stores a current state of the fastboot flag.

8. A method as in claim 5 , further comprising:

after the fastboot flag is set to the de-asserted state and in response to a failure of the set of critical boot activities to complete successfully, reading the fastboot flag from the location in the memory device, and

in response to the fastboot flag being set to the de-asserted state, (i) performing the full-boot procedure, (ii) re-setting the fastboot flag in the location in the memory device back to the asserted state, and (iii) transitioning the data storage system from operating in the booting mode back to operating in the normal operating mode in which the data storage system performs the data storage operations in response to the data storage requests from the set of external host computers.

9. A method as in claim 5 wherein performing the full boot procedure includes:

performing, as one of the set of avoidable boot activities, a firmware version comparison operation that compares a version identifier of a currently running version of firmware to a version identifier stored in the memory to determine whether to perform a firmware upgrade; and

wherein the fastboot procedure avoids performance of the firmware version comparison operation before transitioning the data storage system from operating in the booting mode back to operating in the normal operating mode.

10. A method as in claim 5 wherein performing the full boot procedure includes:

performing, as one of the set of avoidable boot activities, a power on self test (POST) error check operation that checks for POST errors; and

wherein the fastboot procedure avoids performance of the POST error check operation before transitioning the data storage system from operating in the booting mode back to operating in the normal operating mode.

11. A method as in claim 5 wherein performing the full boot procedure includes:

performing, as one of the set of avoidable boot activities, backup boot partition and root-recovery partition validation operations that check a backup boot partition and a root-recovery partition of the data storage system for consistency; and

wherein the fastboot procedure avoids performance of the backup boot partition and root-recovery partition validation operations before transitioning the data storage system from operating in the booting mode back to operating in the normal operating mode.

12. A method as in claim 5 wherein performing the full boot procedure includes:

performing, as one of the set of avoidable boot activities, boot, root, and swap partition validation operations that check a boot partition, a root partition, and a swap partition of the data storage system for consistency; and

wherein the fastboot procedure avoids performance of the boot, root, and swap partition validation operations before transitioning the data storage system from operating in the booting mode back to operating in the normal operating mode.

13. A method as in claim 5 wherein each of (i) performing the full-boot procedure and (ii) performing the fastboot procedure includes:

after performing a series of boot operations from an initial root file system, performing a file system pivot operation to perform as subsequent series of boot operations from a storage array root file system in place of the initial root file system.

14. A method as in claim 13 wherein performing the full boot procedure includes:

performing, as at least some of the set of avoidable boot activities, (i) a firmware version comparison operation that compares a version identifier of a currently running version of firmware to a version identifier stored in the memory to determine whether to perform a firmware upgrade, (ii) a power on self test (POST) error check operation that checks for POST errors, and (iii) backup boot partition, root-recovery partition, boot partition, root partition, and swap partition validation operations that check a backup boot partition, a root-recovery partition, a boot partition, a root partition, and a swap partition of the data storage system for consistency; and

wherein the fastboot procedure avoids performance of (i) the firmware version comparison operation, (ii) the POST error check operation, and (iii) the backup boot partition, root-recovery partition, boot partition, root partition, and swap partition validation operations before transitioning the data storage system from operating in the booting mode back to operating in the normal operating mode.

15. A method as in claim 1 , further comprising:

after the data storage system has transitioned to operating in the normal operating mode, writing host data into and reading host data from an array of storage devices in response to host input/output (I/O) requests from the set of external host computers.

16. A method as in claim 15 , further comprising:

after the data storage system has transitioned to operating in the normal operating mode and in response to a cold boot event, transitioning from operating in the normal operating mode to operating in the booting mode and, while operating in the booting mode, re-performing the full-boot procedure which includes the set of critical boot activities and the set of avoidable boot activities.

17. A method as in claim 1 , further comprising:

after the data storage system has transitioned to operating in the normal operating mode, performing data storage operations on behalf of the set of external host computers while the fastboot notification is provided within the data storage system to indicate to the data storage system that the fastboot procedure is to be performed in response to the warm boot event.

18. Data storage equipment, comprising:

a communications interface;

memory; and

control circuitry coupled to the communications interface and the memory, the memory storing instructions which, when carried out by the control circuitry, cause the control circuitry to:

perform a full-boot procedure which includes a set of critical boot activities and a set of avoidable boot activities,

in response to completion of the full-boot procedure, provide a fastboot notification indicating to the data storage system that a fastboot procedure is to be performed in response to a warm boot event, and

after providing the fastboot notification, place the data storage system into the normal operating mode in which the data storage system performs data storage operations in response to data storage requests from a set of external host computers received through the communications interface;

wherein the control circuitry performs the full-boot procedure and provides the fastboot notification while the data storage system operates in a booting mode in which the data storage system does not yet perform the data storage operations in response to the data storage requests from the set external host computers; and

wherein the control circuitry, when placing the data storage system into the normal operating mode, is constructed and arranged to transition the data storage system from operating in the booting mode to operating in the normal operating mode.

19. Data storage equipment as in claim 18 wherein the control circuitry is constructed and arranged to:

in response to the fastboot notification indicating to the data storage system that the fastboot procedure is to be performed in response to a warm boot event, perform a fastboot procedure rather than the full-boot procedure in response to the warm boot event.

20. A computer program product having a non-transitory computer readable medium which stores a set of instructions that directs a data storage system to reach a normal operating mode in which the data storage system performs data storage operations in response to data storage requests from a set of external host computers; the set of instructions, when carried out by computerized circuitry of the data storage system, causing the computerized circuitry to perform a method of:

performing a full-boot procedure which includes a set of critical boot activities and a set of avoidable boot activities;

in response to completion of the full-boot procedure, providing a fastboot notification indicating to the data storage system that a fastboot procedure is to be performed in response to a warm boot event; and

after providing the fastboot notification, placing the data storage system into the normal operating mode in which the data storage system performs the data storage operations in response to the data storage requests from the set of external host computers;

wherein performing the full-boot procedure and providing the fastboot notification occur while the data storage system operates in a booting mode in which the computerized circuitry of the data storage system does not yet perform the data storage operations in response to the data storage requests from the set external host computers; and

wherein placing the data storage system into the normal operating mode includes transitioning the data storage system from operating in the booting mode to operating in the normal operating mode.

21. A computer program product as in claim 20 wherein the method further comprises:

in response to the fastboot notification indicating to the data storage system that the fastboot procedure is to be performed in response to a warm boot event, performing a fastboot procedure rather than the full-boot procedure in response to the warm boot event.