US 11,989,447 B1
Data storage system with non-disruptive upgrade using co-existing ring-based and pool-based write logs
Alexander Shknevsky, Fair Lawn, NJ (US); Oran Baruch, Tel Aviv (IL); and Vladimir Shveidel, Pardes-Hana (IL)
Assigned to Dell Products L.P., Round Rock, TX (US)
Filed by Dell Products L.P., Round Rock, TX (US)
Filed on Nov. 22, 2022, as Appl. No. 17/992,152.
Int. Cl. G06F 3/06 (2006.01)
CPC G06F 3/0656 (2013.01) [G06F 3/0604 (2013.01); G06F 3/0679 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A method of non-disruptively transitioning a data storage system from using a ring-based write log to using a pool-based write log for temporarily buffering data being written to persistent secondary storage of the data storage system, the method comprising the steps, performed as background operations concurrently with ongoing foreground processing of data storage read and write operations, of:
initially creating the pool-based write log based on contents of the ring-based write log, and beginning to mirror updates of the ring-based write log to the pool-based write log to establish synchronism therebetween;
subsequently, and based on an update flag indicating that an update process for the data storage system has not yet completed, continuing to mirror updates of the ring-based write log to the pool-based write log to maintain synchronism therebetween; and
subsequently, and based on the update flag indicating that the update process for the data storage system has completed, commencing exclusive use of the pool-based write log and making the ring-based write log available for eventual removal.