Can VSAN hosts access FC-SAN storage in the same time?

[JoakimA]

Soon we will invest in new ESXi hosts and we would like to design them for capability of VSAN. But since VSAN is a pretty new technology we also want the same hosts to act as our old hosts and have datastores in our SAN environment (FC SAN attached storage).

Can VSAN hosts access VSAN storage and FC-SAN storage in the same time?

What pros and cons can you see with this design?

[Cormac Hogan]

Yes, there is nothing to stop an ESXi host participating in both a VSAN cluster, and also accessing other storage over supported protocols such as NFS, FC, FCoE or iSCSI.

However, you will not be able to use the LUNs or Volumes presented over NFS, FC, FCoE or iSCSI for VSAN storage.

VSAN requires local disks to build the VSAN datastore.

I guess the only concern would be the additional management overhead that comes with having lots of different storage types, but this is true even if VSAN wasn't in the picture.

[Nicholas Bowie]

Hi Cormac,

Would it then be true to state that if a VM were running on the compute nodes of a VSAN cluster, but with its storage provided by an external array, that the standard ESXi 5.5 configuration maximums apply (notably: larger than 2TB volumes)? And, with that in mind, would it be supported to have a VM running system disks off of VSAN, yet have a >2TB data volume presented to it that is backed by an external array or does a VM have to exist on one storage system type only?

Just looking at the use case of utilizing policies to define virtual san storage as something like tier 2/3, and have the external array as tier 1. This is not performance based, but rather availability as an external array could support synchronous array based replication.

Thanks in advance,

NickB

[Cormac Hogan]

I don't see any issues with this at first glance Nick.

My only concern is that it might become a bit of a pain to manage.

But sure, you can deploy your VM boot disk to VSAN, and then add VMDKs from your SAN or NAS storage to the VM afterwards.

[Nicholas Bowie]

Thanks - just confirming for a potential fringe use case. :smileyhappy:

[Vikas Shitole]

Agree with above response by CHogan

[Vikas Shitole]

Yes. Along with VSAN storage, vSAN host will have access to FC-SAN as well.  I do not see any cons. vSAN is about leveraging your local storage effectively in order to save cost on dedicated shared storage like FC/iSCSI.  HA/DRS are supported on vSAN.

Message was edited by: Vikas

[Cormac Hogan]

DPM is not supported.

The reason for this is that we might have a host in the cluster with no running VMs, but it may still host VM objects (replicas, stripes, witnesses) for other VMs in the VSAN Cluster.

So we definitely don't want to turn it off because of this.