Following upgrade from ESXi 7.0.x to 8.0.x, iSCSI datastores are not mounted

Products

• VMware vSphere ESXi

Issue/Introduction

• Following upgrade from ESXi 7.0.x to 8.0.x, direct-attached iSCSI datastores, with the following configuration, are not mounted: 
  • Software iSCSI
  • Multiple iSCSI vmkernel ports
  • Above vmkernels are all in the same subnet
  • These vmkernels are connected without a switch to separate iSCSI targets
  • Port binding enabled.
• /var/log/syslog.log reports repeated login timeouts
• /var/log/vmkernel.log reports iSCSI repeatedly going offline and online.
• HEXDUMP of iSCSI LUN fails to read the LUN data. 

Environment

VMware vSphere ESXi

Cause

This appears to be similar to an invalid port binding configuration, where each vmkernel connected to the port group cannot access all the targets. 

While this does not appear to be problematic in ESXi 7.x, it causes the symptoms described above in vSphere ESXi 8.x.  

Resolution

Follow one of the below workaround:

• Connect the hosts to the iSCSI targets via a switch, so that each iSCSI vmkernel port can connect to each target.
• Configure each iSCSI vmkernel port and its connected target to be in a separate subnet, and do not enable port binding.
• Simplify the configuration to have one iSCSI vmkernel port connected to a single target (useful for testing purposes, but does not provide path redundancy)

Additional Information

For more information on the configuration of Software iSCSI on ESXI hosts, please refer article: Configure the Software iSCSI Adapter with ESXi