This article summarizes several recent cases of VMware Horizon virtual desktops encountered in the version upgrade or use of the fault and its solutions, and hope to help readers with the same problems.
1 Thin client cannot log in after Horizon Connection Server is upgraded to 7.10
A company uses DELL Wyse 5030 Zero Client (thin client) to log in to the virtual desktop of VMware Horizon 7.5. After upgrading the Horizon Connection Server and Composer Server to 7.10, some workstations prompt "View Connection Server communication error" when logging in to the virtual desktop, as shown in Figure 1. Some workstations log in normally. 
Figure 1 Some thin clients cannot log in.
After inspection, it is found that the thin client firmware version 5.51 can log in, but the 4.8 version does not. It can be solved by upgrading the thin client firmware. as shown in picture 2. 
Figure 2 Upgrading the thin client
2 Cannot edit virtual desktop pool
Log in to Horizon Administrator, and in "Directory→Desktop Pool", when double-clicking the configured desktop pool to edit, the error "Server Error→Unknown" appears, as shown in Figure 3. 
Figure 3 An unknown error occurs.
If you create a new desktop pool, in the "vCenter Settings" step, when you select "Host or Cluster", a "java.lang.IllegalArgumentException: Invalid parameters" error appears, as shown in Figure 4. 
Figure 4 Error
The reason for this error is generally that there are offline hosts among the ESXi hosts currently managed by vCenter Server. For example, in the current virtualization environment, a vSAN environment composed of 4 ESXi 6.7 hosts, but one of the hosts fails offline. If the faulty host cannot be repaired for a short period of time, the faulty host should be temporarily removed from vCenter Server to resolve the fault. After the failed host is repaired, rejoin the cluster.
3 Connection server copy is out of sync
There are two Horizon 7.5 connection servers in an environment, one is the Horizon connection server, and the other is a replica server of the first connection server. When upgrading two Horizon connection servers to 7.10, the first connection server was successfully upgraded. When upgrading the second connection server (replica server), the message "LDAP is not ready, there is a replication problem related to the server VCS02 ", as shown in Figure 5. 
Figure 5 Replication problem
The main reason for this failure is that the connection server (replica) has not synchronized with the first connection server for a long time. Because the first connection server is normal, if you want to solve this problem, you can uninstall the second connection server (copy) and AD LDS instance, then reinstall the connection server (copy), and re-copy data from the first server. can.
(1) Uninstall VMware Horizon 7 Connection Server, VMware Horizon 7 HTML Access, AD LDS instance VMware VDMDS in "Programs and Features", as shown in Figure 6. 
Figure 6 Uninstall the connection server and its components
(2) When uninstalling the "AD LDS instance VMware VDMDS" component, select "Skip all", as shown in Figure 7. 
Figure 7 Skip all
(3) Click the "Close" button in the "AD LDS successfully deleted" dialog box, as shown in Figure 8. 
Figure 8 Successfully deleted AD LDS
(4) Run the Horizon 7.10 connection server installation program, select the replica server, as shown in Figure 9. 
Figure 9 Install the replica server
(5) Specify the domain name or IP address of the first connecting server in the "Source Server", as shown in Figure 10. 
Figure 10 Specify the source server
(6) In the "VMware Horizon 7 Connection Server" dialog box, a warning prompt of "The specified Horizon 7 connection server already contains the copy configuration of this computer, do you want to continue and use the copy configuration information in this computer to overwrite this configuration" Click the "OK" button, as shown in Figure 11. Then follow the wizard to complete the installation. 
Figure 11 Confirmation.
Finally, you can see in "View Configuration→Server→Connect Server" on the Horizon administrator management interface that the two servers are already 7.10 versions, as shown in Figure 12. 
Figure 12 View the connection server version
4 Loss of the parent virtual machine causes desktop reconstruction failure
A multimedia classroom in a university library, VMware vSphere 5.5 environment, 7 ESXi hosts, 1 EMC storage, and VMware View 5.2 virtual desktop (the virtual machine operating system is Windows XP). There are 80 terminals using the desktop. Once a storage failure was repaired, some desktops could be used, and some desktops could not be logged in.
(1) Log in to Horizon Administrator, in "List→Desktop", it is found that some desktops are in the status of "Unable to access the agent", and some desktops are in the status of "Deployed (missing), as shown in
Figure 13. Figure 13 Desktop list
(2) When checking the "Desktop Pool" and editing the desktop pool, in the "Parent Virtual Machine" of "vCenter Server Settings", the original parent virtual machine of the desktop pool is not found. The name of the parent virtual machine of this desktop pool is XP_SP3, such as As shown in
Figure 14. Figure 14 Cannot find the parent virtual machine.
After asking the administrator, it is learned that when the storage fails, all data on a LUN is lost. The parent virtual machine of the desktop pool named XP_SP3 and some desktops are stored in this storage In. Because all LUN data is lost, some virtual desktop virtual machines are lost, but after using the reconstruction function, the reconstruction fails
because the parent virtual machine cannot be found. Because there are multiple LUNs currently stored, some virtual desktops can still be used You can use a usable virtual desktop as a basis to clone a new virtual machine and use it as a new parent virtual machine for the desktop pool. In addition, when deploying a virtual desktop pool linked by the clone, Horizon will copy a copy called replica -xxxx virtual machine as the basis, and create a cloned virtual machine based on it. At this time, you can find the virtual machine named replica-xxxx in the current environment and check which one is cloned from the XP_SP3 parent virtual machine The template virtual machine is fine. After inspection, it is found that there are 4 virtual machines starting with replica-xxxx, as shown in Figure 15. There should be a virtual machine that is the template virtual machine we need.
Figure 15 Finding the beginning of replica virtual machine
By browsing the storage comparison, it is found that the name replica-5ec3b233-836e-437e-8370-8b9449c814ea is the virtual machine we need, as shown in Figure 16.
Figure 16 Finding the reference virtual machine cloned by
XP_SP3 After finding the cloned virtual machine of XP_SP3, right-click the virtual machine and select "Clone", and set the name of the new virtual machine to XP_SP3_New, as shown in Figure 17.
Figure 17 Clone the virtual machine After
cloning the virtual machine, turn on the power of the virtual machine and enter the console to check whether the virtual machine is the desired virtual machine. After checking it is correct, turn off the power of the virtual machine, and then the virtual machine named XP_SP3_New Create a snapshot and set the snapshot name to fix01.
Edit the virtual machine desktop pool again. In "vCenter Settings", the parent virtual machine selects the newly cloned virtual machine named XP_SP3_new, selects the snapshot name as fix01 (as shown in Figure 18), and selects the virtual machine folder and host Or clusters, resource pools, data storage, etc. These are the same as the original settings.
Figure 18 vCenter settings After
editing the desktop pool settings, in "List→Desktop", right-click the virtual machine with the status "Deployed (missing)", and select the "Remove" command in the pop-up right-click menu, as shown in the figure 19 shown. Delete the failed virtual desktop, and the virtual desktop will be recreated.
Figure 19 Remove the faulty virtual desktop virtual machine
Click the "OK" button in the pop-up "Remove Virtual Machine" dialog box, as shown in Figure 20.
Figure 20 Deleting the virtual machine After
removing all the problematic desktops, Horizon will rebuild the deleted desktops and then redeploy the virtual desktops. Finally, all desktops are "available" in the "status", as shown in Figure 21, the desktop reconstruction is complete.
Figure 21 The virtual desktop status is normal.
After some virtual desktops were reconfigured, the user found that the thin client could not access the virtual desktops. This problem was solved by restarting the connection server virtual machine.
For some virtual desktops that cannot be used, reset the virtual desktop or reconstruct the virtual desktop.
In the process of regenerating new virtual desktops in large quantities, errors may occur on individual desktops. For virtual desktops with errors, you can solve them by removing the faulty virtual desktops and regenerating them.
For more content about VMware Horizon desktop, please see the following books or videos:
VMware Horizon Virtual Desktop Application Guide
https://item.jd.com/13038424.html
Use NVIDIA RTX8000 to configure GPU virtual desktop
https://edu.51cto.com/sd/952a9
Other books and videos
========== Video===================
VMware ESXi and vCenter Server installation and upgrade experimental video course
https://edu. 51cto.com/sd/e1e6b
VMware vSphere 6.7 Virtualization Introduction Video Course
https://edu.51cto.com/sd/22fe0
VMware vSAN 6.7 actual combat exercise
https://edu.51cto.com/sd/c6449
In-depth study of VMware Horizon View7 virtual desktop
https://edu.51cto.com/sd/225f2
SMEs vSphere virtualized data center planning and design and product selection
https://edu.51cto.com/sd/04e53
VMware Server Virtualization Improvement: Virtualization Infrastructure Configuration Video Course
https://edu.51cto.com/sd/b9594
Forget the VMware ESXi and vCenter Server password solution video tutorial
https://edu.51cto.com/sd/993e5
=======Books===============
VMware Virtual SAN hyper-converged enterprise application combat
https://item.jd.com/12842654.html
VMware vSphere 6.5 enterprise operation and maintenance combat
https://item.jd.com/12329944.html
VMware virtualization and cloud computing: vSphere operation and maintenance volume
https://item.jd.com/12237563.html
VMware Virtualization and Cloud Computing: Troubleshooting Volume
https://item.jd.com/12478965.html