Operating in a write through mode transition while maintaining data integrity after an abrupt shutdown on a storage device

A method for transitioning from operating in a write-back mode to a write-through mode on a storage device and for using a transition mode to maintain data integrity on a boot-up, the storage device comprises a controller to execute the method comprising:

• operating in a write-back mode when a capacitor power is greater than a threshold that is set for a capacitor to flush acknowledged host data in a volatile memory to a persistent memory during a power loss protection shutdown process in an ungraceful shutdown and flushing acknowledged host data in a volatile memory to a persistent memory;
• entering a read-only mode on boot up of the storage device when the controller determines that a recovery during the power loss protection shutdown process is incomplete;
• switching to operate in a write-through transition mode and storing a first transition flag in the persistent memory when the capacitor power is less than the threshold and flushing the acknowledged host data in the volatile memory to the persistent memory;
• maintaining the storage device in the write-through transition mode after a successful power loss protection shutdown process while the storage device is in the write-through transition mode and the first transition flag is stored in the persistent memory and entering a read-only state after an unsuccessful power loss protection shutdown process while the storage device is in the write-through transition mode and the first transition flag is stored in the persistent memory and
• storing a second transition flag in the persistent memory to prepare the storage device to enter the write-through mode and moving to a write-through mode when the acknowledged host data is copied to the persistent memory.

A storage device to transition from operating in a write-back mode to a write-through mode and to use a transition mode to maintain data integrity on a boot-up, the storage device comprising:

• a volatile memory to store acknowledged host data;
• a persistent memory to store the host data;
• and
• a controller to
• boot-up the storage device and obtain a drive state,
• determine if the storage device is operating in one of a write-back mode, a write-through transition mode, and a write-through mode, wherein in the write-through transition mode the controller stores a first transition flag in the persistent memory and flushes the acknowledged host data in the volatile memory to the persistent memory,
• enter a read-only state if the storage device is operating in one of the write-back mode and the write-through transition mode and a previous shutdown is incomplete,
• perform an ungraceful shutdown recovery if the storage device is operating in the write-through mode and the previous shutdown is incomplete, and complete the boot-up in one of the write-back mode, the write-through transition mode, and the write-through mode that was used prior to the previous shutdown if the previous shutdown is complete.