Summary
This is an informational event indicating that a previously reported volume connectivity problem has been corrected and connectivity to the volume restored. Every 16 seconds the ESXi host sends a heart beat to the LUNs it knows about presented by an array. If the array does not respond then the host marks the LUN(s) as inactive and the Lost access to the volume message is presented. If we get a heartbeat from the LUN at the next cycle then the volume connection is restored and this event is reported.
For example: If a VMFS volume is recovered after a fault (such as a cable connection fault), the following is displayed:
Successfully restored access to volume 496befed-1c79c817-6beb-001ec9b60619 (san-lun-100) following connectivity issues.
Impact
The effect of lost connectivity is that all I/O to the volume is rejected, and the virtual machines and their applications register errors and transactions fail. However, restoration of volume connectivity allows all pending I/O to proceed. The effect on virtual machines vary according to traffic volume to/from the LUN(s) in question, timeout settings for the traffic, and the duration of the outage.