• vCenter Server alarm on an ESXi 5.5 host reports:
  
  Alarm Definition:
  ([Event alarm expression: Host error] OR [Event alarm expression: Host warning])
  
  Event details:
  Issue detected on xxxxxxx in xxxxxxx : Error (1) saving state to /bootbank
   
• In the /var/log/vmkernel.log file on the affected ESXi host, you see entries similar to:
  
  ALERT: Error (1) saving state to /bootbank
   
• In the /var/log/vmkwarning.log file on the affected ESXi host, you see entries similar to:
  
  ALERT: Error (1) saving state to /bootbank

• ESXi 5.0 Patch 10 (Build 2312428). For more information, see VMware ESXi 5.0, Patch Release ESXi500-201412001 (2088715)
• ESXi 5.1 Update 3, available at VMware Downloads. For more information, see the VMware ESXi 5.1 Update 3 Release Notes.
• ESXi 5.5 Patch 03 (Build 2143827). For more information, see VMware ESXi 5.5, Patch Release ESXi550-201410001 (2087358).

Note: If the issue persists, contact VMware support and file a support request with VMware Support and quote this Knowledge Base article ID ( 2057826) in the problem description. For more information, see Filing a Support Request in Customer Connect (2006985).

Note: ESXi host uses a non-persistent memory based file system. By default, configuration changes are written to the bootbank every hour by auto-backup.sh cronjob script or whenever there is a change invoked by internal/user invoked operation through backup.sh script. When the non-persistent memory based file system is unable to write to the bootbank and you must reboot the ESXi, any configuration change made since the last successful write will be lost.