It's troubling when you find out that a host or a storage processor does not have the intended multipathing configuration; this configuration will ensure that an ESXi host is connected to the storage processor with redundant mechanisms. The best example in the block storage world is an ESXi host that has two fibre channel host bus adapters (HBAs) that are connected to two switches where each switch has a fibre channel connection to the storage processor. This simple example is represented in Figure A. Figure A
There are a number of tools that will explore storage fabrics to document configurations. Some of the tools are free from the HBA makers, such as SANsurfer and HBAnywhere; for purchase, products such as NetApp's SANscreen also provide expanded visibility to storage networks. VMware has a new map view for the datastore; the map view is good for mapping hosts to networks and datastores, but the datastore-specific map view has additional information.
To access the datastore map view, browse in the vSphere Client to Home | Inventory | Datastores and then click the Storage Views tab and select the Maps view. From there, you can create a map view that will show connectivity from the datacenter to the target.In my personal lab, I have a small iSCSI SAN that provides my vSphere test environment. It is a single-path solution, but the Storage Views functionality shows that connectivity end-to-end for the four ESXi hosts I have installed quite well. Figure B shows a single datastore's map. Figure B
Click the image to enlarge.The only negative to Storage Views and all of vSphere's mapping capability is that longer names don't fit well into the view. The views can be rotated to have a view from the host's perspective, rather than a single datastore. Various controls can be added to select elements, such as vmhba units on the host, SCSI targets, and virtual machines. Figure C shows a single host from the LAB-RICKATRON datacenter displaying all storage elements except virutal machines and datastores. Figure C
Click the image to enlarge.
As you can see, Storage Views are a very detailed view into the mulitpathing and storage configuration as presented to the ESXi hosts. This quickly identifies any limited or broken paths from the vSphere perspective to verify the storage provisioning configuration against what the storage processor may be configured.
How do you use Storage Views for your vSphere storage management? Share your tips below.
Rick Vanover is a software strategy specialist for Veeam Software, based in Columbus, Ohio. Rick has years of IT experience and focuses on virtualization, Windows-based server administration, and system hardware.