Upgrades to ESXi 7.0 from an ESXi 6.x host with iSCSI devices might fail with a fatal error message during ESXi booting

Products

• VMware vSphere ESXi

Issue/Introduction

Symptoms:

• Upgrades to ESXi 7.0 from an ESXi 6.x custom image or standard image with an async version of offload iSCSI drivers might fail with messages similar to Fatal Error: 15 (Not Found) or Error loading /vmfs/volumes//b.b00. 
• The affected offload iSCSI driver sets are bnx2i/qfle3i, be2iscsi/elxiscsi, and qedil/qedi. The issue might also occur in environments with a software iSCSI and iSCSI Management API plugins. 
• The above messages are seen in ESXi loading page during the reboot phase of the upgrade by using either vSphere Update Manager or ESXCLI. In vSphere Update Manager, the ESXi  system rolls back to the previous image upon reset. 
• Mostly this issue affects with iSCSI enabled QLogic 578XX converged network adapters (CNA) or iSCSI enabled Emulex OneConnect CNAs, or QLogic FastLinQ QL4xxxx CNAs, or software iSCSI configurations. The problem does not occur if the CNA is only configured for FCoE.

Environment

VMware vSphere ESXi 7.0.0

Resolution

This issue is fixed in ESXi 7.0b.

On the impacted hosts, upgrade to ESXi 7.0 using ESXi 7.0b based VMware stock ISO or OEM Custom Images.