iSCSI target service may be interrupted if host agents are restarted

Products

• VMware vSAN

Issue/Introduction

• The vSAN iSCSI target service may be interrupted if ESXi host agents are restarted.
  The vSAN iSCSI target service I/O may be interrupted, and the service may not start after restarting the ESXi host agents.
  In the /var/run/log/vitd.log, you see similar to:
  
  2020-01-01T05:55:55Z vitd: [etc/init.d/vitd] SIGKILL has been sent to vitsafehd
2020-01-01T05:55:55Z vitd: [etc/init.d/vitd] vitd is not running
2020-01-01T05:55:55Z vitd: [etc/init.d/vitd] vitsafehd is not running

Environment

6.x
7.x
8.x

Cause

When the ESXi host agents are restarted, the vSAN iSCSI vitd service, vitsafehd service, and watchdog agent will be restarted. As these are vSAN processes the ESXi host agent is unable to restart these services.

Resolution

If ESXi host agents have been restarted and vSAN iSCSI is not functioning as intended, run the following command on the affected ESXi hosts:
  /etc/init.d/vitd io_reset

Additional Information

vSAN Health Service - vSAN iSCSI target service – Service runtime status

Impact/Risks:
vSAN iSCSI I/O may be interrupted.