pdrace
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NFS Configuration questions

We are migrating to new NetApp MetroCluster storage. All storage is NFS.

In the past our storage targets only had one IP address to connect to so there was a question about what address to connect to.

the storage targets on the new system has 2 IP addresses to target. My questions are.

1. Is it necessary to connect volumes to the same IP address across hosts for vmotion compatibility oor does it just look at the Datastore name?

2. Is it best practice to add both IP addresses when you mount a volume to a cluster?

I opened a call with VMware but made it stupidly made it low priority, who knows when I'll hear from them.

Thanks

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sjesse
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scott28tt
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pdrace
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We have no plan to use storage DRS. VMWare Support tells me that if datastores are mounted via different IP addresses that will break VMotion compatibility.

Then they go onto say it is best practice to add all available IPs to the mount.
If you do that across different clusters how can you guarantee vmotion compatibility across clusters?What if the datastore is mounted by one of the addresses on one cluster and on another address on another cluster?

Support doesn't seem to understand the question about multiple addresses.

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sjesse
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Your better off asking NetApp, as I think it depends on how the metro cluster is setup. Either way you can't specify two ips for one datastore to connect to, when you connect a nfs datastore you just pick one. For any type of load balancing or something similar that's done on the storage side. You can though have nfs datastores connected to different ips, there is no requirement where you can only have one, its not like iscsi where you specify one discovery address,

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pdrace
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Yes you can specify multiple IP addresses when you mount an NFS volume.

I'm not clear which address the volume gets mounted on though, the first one added?

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sjesse
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Sorry thats correct, in regards to multipathing, and its only in nfs 4.1 which the 9 version of oncommand can do, nfs3 could only do a one to one map.. As long as both ips will see the same volume ans use the same folder structure there shouldn't be any issue. I do think there are netapp  For vmware you just need to meet there criteria, and after that you should follow all storage vendor requirements

NFS Server Configuration

pdrace
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It's VMWare that is the issue. On one hand they tell me it is best practice to add multiple addresses when mounting a volume but on the other hand they say volumes won't be vmotion compatible between hosts if they are mounted on different IP addresses.  They're just ignoring that part of the question. I have to mount the same volumes in different clusters and even different site.


How do I mount them? Use multiple target addresses and just make sure the same address is always added first when mounting to each cluster?

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sjesse
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You just add both doesn't matter the order, and it depends on the mutipath selection policy, which is only round robin. It will send traffic to one ip and then the other, look at this link I just found that shows this concept.

NFS 4.1 Multipathing Configuration and Best Practices | Storage and Networking | VMware vSphere Cent...

For vmotion, there is nothing that I've ever head of that wouldn't make them not vmotion compatible. The only vmotion requirements are listed here

Storage vMotion Requirements and Limitations

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