DataKeeper for Windows All Documentation - SIOS

Split-Brain FAQsAnswerYes, beginning with Version 7.4, users can extend and shrink their DataKeeper volumes dynamically whileretaining mirror settings. See DataKeeper Volume Resize for more information.Split-Brain FAQsScenarioI am using DataKeeper in a non-cluster environment. I am mirroring from Server1 at one site to Server2 at asecond site. Communication is broken due to site-to-site VPN, and I need to fail over from Server1 to Server2.I cannot access Server1 from anywhere. Server1 is actually still on but not reachable internally or externally,and there may be some processes still running in the backend.QuestionHow can I fail over from Server1 to Server2?AnswerUsing the SWITCHOVERVOLUME command or the Switchover Mirror option in the DataKeeper UI, switchthe source of the mirror to Server2. There will be a delay while the Target tries to connect to the Source, butthat should complete in 30-40 seconds or so.QuestionDuring the switchover period, both Server1 and Server2 are writing new data to the disk (Volume F on bothServer1 and Server2). When the connection comes back online, will Server1 automatically become theTarget?AnswerNo. This scenario will cause a split-brain condition. Perform one of the following to resolve this issue:• Using the DataKeeper User Interface, perform the Split-Brain Recovery Procedure.or• Run the EMCMD PREPARETOBECOMETARGET command on the system that is going to becomethe Target, and then run the CONTINUEMIRROR command on the system that is going to becomethe Source.QuestionWhich of the two methods above do you recommend for resolving the split-brain issue?AnswerWhichever you prefer - they both perform the same functions.QuestionCan the command for the Target server be run from the Source server?DataKeeper for Windows Technical DocumentationPage 158