Patent ID: 9614716
Date: 2017-04-04
CPC Classifications: H04L

Claim:
1. A method for performing maintenance to controllers in a network-attached storage system that includes two or more controllers, each controller including one or more associated IP addresses, the method comprising: identifying, by a computer, an online controller in the network-attached storage system to upgrade, wherein the network-attached storage system is a special purpose computer that provides a plurality of file-based storage services to a plurality of other computing devices, wherein the network-attached storage system is connected to a domain name server, wherein the domain name server is not resent as a failover solution for the network-attached storage system, and wherein the network-attached storage system includes a hot spare controller in a standby mode: transmitting, by the computer, the one or more associated IP addresses of the online controller to upgrade to a hot spare controller in the network-attached storage system, wherein the hot spare controller is taken out of the standby mode and upgraded before the one or more associated IP addresses are transmitted; simultaneous with when the hot spare controller is online, taking, by the computer, the online controller to upgrade offline, wherein taking the online controller to upgrade offline further comprises draining, by the computer, the online controller to upgrade, and wherein draining the online controller comprises removing all of a plurality of stateful sessions from the online controller to upgrade before taking the online controller offline; and upgrading, by the computer, the controller to upgrade.