Symptoms
An enclosure was removed after destroying all the configuration - Unbinding LUNs, Destroying pool (Internal RGs ) thereby leaving the corresponding disks unbound and finally removing enclosure off the array.
Note : This article is not applicable if the enclosure was removed when the drives were still bound and current state of Pool internal RG's are Broken.
Ghost enclosure showing up in Unisphere on a VNX2 array
Cause
The PVD (Provisioned Virtual Drive ) state of a drive's would be kept for 7 days.
The reason behind keeping the state for 7 days is to support the notion of portable drives and save the disk zeroing process.
If the drives are removed and re-inserted in array within 7 days of removing these disk's, it will be recognized and would not be zeroed which saves time.
However, if the drive's are removed for more than a week and re-inserted again, it will be considered new drive's and will be zeroed since the PVD state will be erased from the database.
Resolution
If an enclosure was removed after destroying all the configuration - Unbinding LUNs, Destroying pool (Internal RGs ) thereby leaving the corresponding disks unbound and finally removing enclosure off the array, then wait for 7 days and the enclosure should automatically disappear by design.
A management server restart will not make any difference/help in this case.
In this scenario - The enclosure would be a ghost enclosure since the drives PVDs (Provisioned Virtual Drive) still exists in array database, even though the unbound drives have been removed from the array.