boot disk inaccessible

[VPXA]

Hi,

In one of our new cluster with 6.5u3, we have 8 hosts UCS BL's,  from these 4 hosts are unable to access the local datastore i.e., boot disk (SAN Boot), remaining hosts working fine, after couple of reboots also having the same issues. 

can we suspect any Hardware related issues, please provide me your suggestions.

[e_espinel]

Hello.

The failure of several Blades in a chassis at the same time is very unlikely, this may be a configuration error, firmware levels and / or compatibility between devices.

More details are needed. As you mention a SAN I am going to assume an environment with external storage.
So we have a blade chassis with 8 cisco blade server with Switch SAN in the chassis connected to an external Storage.

Check on the Switch SAN (internal) the following issues:
if you have connection on each port assigned to each Blade server.
Verify if they register errors on those ports.

Verify in the external storage the status of the ports of each blade server registered as host.
Verify the hardware logs of the external storage.

Type, model and part number of the following components are needed:
HBA (card that allows connection of the blade to the SAN).
Internal chassis switch and/or external switch
External storage

Please update this post with the requested information.