Multipathing in VSphere 6

beantownmp

Question came up today. Is multipathing needed at the OS level (RHEL 7) if its done at the Hosts/Datastore level?

We have a new DBA who is VERY new to virtualization is dead set on getting multipathing set up in RHEL but I dont think its as necessary in a virtual environment where its set up between the hosts & datastores.


Thanks!

scott28tt

Leave it to the hypervisor.

Deathmage

I use MPIO in my previous enviromnent and now my new gig, it has its benefits but it won't be like jaw dropping performance, your better off just getting a larger pipe. IE if your 4G go to 8 G FC or if your iSCSI go from 1G to 10G...

beantownmp

Thanks guys. Reassured what I was thinking.

joelsfood

Multipathing, aprticularly with an MPIO agent from the vendor installed, does much more than just add bandwidth. It allows for intelligent path selection between the host and the array, based on queue depth, current load on a particular port (on either host or array side), adjustments basedon available B2B credits in FC, etc, plus the additional redundancy from adding second (or third or eighth) paths for the storage traffic to travel on.

There are use cases for FC passthrough or iscsi access directly from a VM to the array, but the vast majority of the time you want to run multipathing at the host level and then just present storage from a datastore to the VM in questino.

beantownmp

joelsfood wrote: »

Multipathing, aprticularly with an MPIO agent from the vendor installed, does much more than just add bandwidth. It allows for intelligent path selection between the host and the array, based on queue depth, current load on a particular port (on either host or array side), adjustments basedon available B2B credits in FC, etc, plus the additional redundancy from adding second (or third or eighth) paths for the storage traffic to travel on.

There are use cases for FC passthrough or iscsi access directly from a VM to the array, but the vast majority of the time you want to run multipathing at the host level and then just present storage from a datastore to the VM in questino.

Good info. Thanks!