VMAX3 & VMAX All Flash: Cache slot lock cleanup for EDS emulation.


   Article Number:     504592                                   Article Version: 5     Article Type:    Break Fix 




VMAX3 Series,VMAX All Flash





Host encounters performance problem after redundant Director becomes non-operational.                                                           






When a Director fails, each code emulation within HYPERMAX OS performs a cache cleanup routine to unlock cache slots in Global Memory cache, which were in middle of tasks by the failing Director and its emulations.  This unlock routine on the cache (known as Dead Director Cache Cleanup) allows the emulations to either re-purpose the cache slot or re-drive the task to completion by another emulation CPU on live, running Director.  An issue has been found where cache slots with certain conditions and tasks that were locked by an Enterprise Delivery Services (EDS) emulation CPU on a Failed Director do not unlock the cache slots as designed and intended.                                                           






Failed redundant Director                                                           






Dell EMC engineering is currently investigating this problem. A permanent fix is still in progress. Contact the Dell EMC VMAX Support Center or your service representative for assistance and quote this Knowledgebase ID.