Accepted Solution

Metrocluster testing



Hello all,


We are doing 7 mode fabric metrocluster tests on a customer. In almost all the tests we did unti now , have no problem, but in the scenario below, we see that the VMs in the ESXi hosts lost datastores when we shutdown the shelf on that with existing root aggregate of site-A. Do I have to miror root-aggregate on Site-A? Do I have to do this?



MetroCluster Failure Disk Shelf


Expected behaviour: Relevant disks for offline and the plex is broken. There’s no disruption to data availability to hosts running HA (VMware High Availability) or FT (Fault Tolerance), no change is detected by the ESXi Server. When the shelf is powered back on the plexes will sync automatically

Re: Metrocluster testing

[ Edited ]

Yes, root aggregates have to be mirrored.

If you check the messages file you will even see that ONTAP is complaining about the root aggregate not being mirrored.


In that failure case the controller would just access the mirror plex and continue to serve all data.



regards, Niels

Re: Metrocluster testing

hello Niels,


Thanks for quick reply.When I open the NetApp case and ask for 7 mode fabric metrocluster they said that it is not necessary(must) to mirror the root aggregate. Do you mean "have to" for my senario? Or do you always need to mirror it?

Re: Metrocluster testing

In 7-Mode for HA failover to work partner *must* have access to partner root volume - it is not specific to Metrocluster. If root volume is lost, no failover is possible.

Re: Metrocluster testing

In order for that particular failure scenario to work - yes, you have to mirror the root aggregate.

It's generally required to mirror the root aggregate to be fully protected.

For active/passive configurations I have seen people not mirror the root aggregate for the passive controller in order to save on disks, but ONTAP will complain.

In order to have a fully supported and non-complaining system, the root aggregates must be mirrored.


regards, Niels

Re: Metrocluster testing

thanks for all. I would ask just one more question. Is it enough that I move root-volume to any mirrored aggregate for full protection? I would like to underline that is a 7 mode system.

Re: Metrocluster testing

Yes, this is enough.

Re: Metrocluster testing

I'd like to add the in 7-mode, the root aggregate do not need to be separated from the data aggregate.

You could have on single aggregate which is mirrored.

Hope this helps.