vSAN iSCSI Target Service Interrupt During Upgrading From Pre-vSAN 6.7 to vSAN 6.7 or later

Products

• VMware vSAN

Issue/Introduction

This article provides information on upgrading ESXi Host from pre-6.7 version to vSAN 6.7 version or later when vSAN iSCSI Target service is enabled and iSCSI LUN currently serving I/Os. During upgrade, vSAN iSCSI connection is lost and all initiators connected to the hosts need to re-login after upgrade completed across all hosts.

Environment

VMware vSAN 6.7.x

Resolution

Perform these steps if the host is installed pre-vSAN 6.7:

1. Stop any I/Os from initiator side being issued to vSAN iSCSI LUNs
2. Disconnect any vSAN iSCSI connections
3. Perform the host upgrade via vCenter to upgrade all hosts
4. After upgrade succeeds on all hosts, initiators need to login to targets again to restore vSAN iSCSI connections
5. Then restart I/O from the initiator side

If hosts installed version is already on vSAN 6.7 or later, no action is needed to upgrade to higher versions. As transparent failover is supported on vSAN 6.7 (supporting WSFC), no I/O interruptions when upgrading from vSAN 6.7 to later versions is expected.

For general ESXi upgrade guidance please see VMware ESXi Upgrade. For more instructions on configuring iSCSI as a service in your vSAN cluster see the Using the Virtual SAN iSCSI Target Service section in the Administering VMware vSAN guide.