Nutanix One-Click Upgrade Error "Nutanix Cluster is under-replicated

One of the biggest operational pain points in 3 Tier architecture is maintenance. Regardless if we talking about Hypervisor upgrade, firmware update or any other maintenace jobs. At the end if one is lucky and all went well, then the mission is accomplished. The procedure of maintenance costs lot of time and money (and sometimes much nerves from the Admin who's  done the Job).
Nutanix has done their Job and gives an Option called "One-Click upgrade". You can do the maintenance Job with one-click (and with no downtime).
If you do an upgrade from NOS (with no Errors) and afterwards an upgrade from the Hypervisorsoftware, you will receive an error message with the following Information:

"Cluster is currently under-replicated"

This message occurs when the health-state from the NTNX-Cluster is on Level "warning" or "error" or the data resiliency state isn't "Ok".

Below is a procedure how to quickly check some states and solve the error:

Step #1 – check if you can see under replication from curator command line.

1. SSH Connection to a CVM
2. Log in with the appropriate credentials
3. curator_cli get_under_replication_info summary=true 

Step #2 - find ID for the last successful curator scan

1. curator_cli get_last_successful_scans 2>/dev/null

Step #3 - check where the curator master is running

1. curator_cli get_master_Location

Step #4 - log in to CVM with curator master is running and manually triger curator scan

1. SSH Connection to CVM with curator master
2. log in with the appropriate credentials
3. allssh curl http://localhost:2010/master/api/client/StartCuratorTask?task_type=2
4. Wait 5-10 minutes and check again if there is any unser replicated data (Step #1)

Template from a virtual machine hosted on AHV (Nutanix)

We can create an image from an existing VM with 1 simple command. SSH into a Controller VM (CVM) and issue the following command:
acli image.create MyTemplateName clone_from_vmdisk=vm:Win2k12-msdn:scsi.0
Replace "MyTemplateName" with the name you want to use for the image.
Replace "Win2k12-msdn" with the name of your VM you want to make into an image.
If needed, replace "scsi.0" with the disk location of the VM’s primary disk.

Nutanix maually create a cluster

1. Make a Connection over ssh to a CVM.
2. Login with correct credentials
3. Type "Cluster -s IP,IP,IP create" and hit Enter.
4. Check Cluster creation with command "Cluster Status"
   If result Looks like "2267 Success!" everything is ok.

Session Negotiation Failed – Horizon View

If you’re upgrading from an earlier version of VMware Horizon View to newer Version (to 6.2 or newer) then you may see clients fail to log-in with error messages that follow similar verbage:
SSL session negotiation failed or The Zero Client may not be compatible with the host session negotiation cipher setting.

The problem occurs because some weaker encryption ciphers that were available in Horizon View 6.1 are now disabled in Horizon View 6.2 and newer; hence the session negotiation failed and/or incompatible cipher error messages.
This issue hit a small portion of our Teradici based zero clients. The problem is that the more preferred ciphers are not supported on Teradici firmware versions below 4.8. If you’re running clients with a firmware version below 4.8 then you will most likely run in to this problem after upgrading to Horizon View 6.2 or newer.
Another temporary work around is to explicitly enable TLS 1.0, 1.1 and 1.2 on your connection servers and your desktop pools (your ‘gold’ base image).
This fixed the problem for us and the fix will be in place until we can be sure that all clients are on the latest firmware version.
Instructions on how to enable the above protocols can be found on KB2130798.

 

Upgrade Foundation 3.0 to 3.1

1. Open the Foundation VM on your workstation.
2. Download the Foundation upgrade bundle (foundation-version#.tar.gz) from the support portal to a convenient location.
3. Enter the following commands:

   $ pkill foundation
   $ cd /home/nutanix/foundation/bin
   $ ./foundation_upgrade -t <path>/foundation-version#.tar.gz
   $ sudo service foundation_service restart

4. Check the upgraded Version with use of 'about' button.