Question on adding new storage (possibly asked elsewhere?)

[PatrickFrith]

Greetings and salutations fellow nerds!

I have a question which may have been answered else where (if so just direct me there).  Also, this question may just be a preference question - if so no problem.

We currently have a clustered 3-host solution running ESXi 6.0 (vCenter 6.0), connected via two Cisco switches to the storage. We are adding new (eventually replacement) iSCSI based storage.

1. Have people had better storage migration results in creating new switches for the new storage's iSCSI connections or in adding connections/adapters within the current virtual switches?
2. The original configuration - built way before I got there - is using standard switches. Is it worth it to move to distributed switches if the environment is only used for testing and R&D. We already have the cluster for HA - does the added configuration of DS add value to a relatively lightly used environment?

Thanks for your input!

Patrick

[a_p_]

1. It depends on the network configuration? If the new storage system is in the same subnet(s), you may not even need to change things on the ESXi side, except for adding/configuring new targets.
2. IMO migrating to vDS may only add value if the network adapters used for iSCSI are not dedicated for it, i.e. are used for other traffic too. In such a case you can benefit from network I/O control with vDS.

André

[PatrickFrith]

Thanks for the reply Andre!

1. As far as the subnets, the old EqualLogic storage used local redundancy instead of multiple subnets. The new storage (EMC M4024) requires use of multiple subnets in its configuration.

2. Thanks for your thoughts.

Cheers!

Patrick

[a_p_]

Sounds familiar, i.e. I'm currently in the same boat. In my case I need to find out the best way to migrate from HPE StoreVirtual (single subnet) to EMC Unity (two subnets). At the same time I have to replace the switches, the ESXi hosts, including CPU family (from AMD to Intel CPUs). All of this with the lowest possible downtime.

Since you are just replacing the storage system (or adding the new one), it should basically be a matter of creating the required iSCSI port groups for all subnets.

Remember to disable explicit port binding in the software iSCSI adapter's settings (which should not be used with multiple subnets) if that's configured.

André