Unable to Remove Stubborn Hosts from Unisphere (and the solution)

November 14th, 2011 by jason Leave a reply »

Last weekend I was working in the home lab and needed to remove a few fibre channel connected hosts from the EMC Celerra NS-120.  This is the procedure I followed:

  1. Open Unisphere
  2. Drill down to the CLARiiON side of the Celerra (APM000…)
  3. From the menu on the left, choose Storage System Connectivity Status
  4. Drill down on the host to remove, highlight each HBA one by one and click the Deregister button
  5. Click OK

Snagit Capture

Unfortunately, I ran into an issue.  The problem which occurred was that the host I was attempting to remove remained in the host list instead of being deleted once the final HBA was deregistered.  This was a problem because I needed to add a new host with the same name.  At this point, there was no clear way to remove the host:

Snagit Capture

Logging in to Engineering mode (I found this on the public facing/Google cached EMC Community Network forums searching for help… CTRL + SHIFT + F12 password messner) did not provide me with additional options to remove the host.

Thanks to the help from Jase McCarty who had a watchful eye on Twitter, I was able to follow a procedure to resolve the situation:

  1. Access each of the Storage Processor Management Servers (http://w.x.y.z/setup)
  2. Scroll down and click the Restart Management Server button (each can be performed in parallel; doesn’t impact storage connectivity)
  3. Wait 5 minutes for the reboot of the Management Servers
  4. Close and Re-open Unisphere
  5. The host is now gone from all host lists.  Problem solved.

This was an isolated incident.  I wasn’t able to repeat this problem but if it happens in the future, I’m ready.  All I have to do is search Google and end up at my own blog.

Thanks Jase!



  1. matt says:

    the solution is partially correct. make sure the box you are trying to remove is either powered off or zoned off at the switch. The HBA in Unisphere will go ‘gray’ and you can delete at will. If you are re-adding the same hostname (different HBAs???) you simply register the new HBA WWID to the host definition.

    EMC’s SP sync is unreliable to say the least and there isn’t a way to force a re-sync expect perhaps via CLI. If you have to reboot, it generally just needs to be the other SP, the one you aren’t working on. Though if you connect to the errant one you may be able to clean up the orphan items and save the reboot.

  2. fu says:

    Thank you!!!

  3. Paul Grevink says:

    Hi Jason,

    Thank you so much for this one, this post was very helpfull and for providing THE password 🙂



  4. Kevin says:

    One thing to remember is that if these are FC initiators, you must disconnect from SAN switches and/or remove from zoning or the array continues to see and display them.

  5. Tony Chops says:

    All i had to do in the same situation was log onto the config page “http://mgt_ip_addr/setup” as the normal admin user, and click “refresh management server state”. The old host was immediately removed from unisphere. Happiness!