How to customize vCenter SSO login page

Lets image that you are sick of the default vCenter default login page and want to add your company logo and name into the SSO login page.

It is possible with both Appliance and Windows Based vCenters.

To carry out the task, you will need the below tools & utilities;

Make sure that you use the PNG format although GIF is apparently supported as well. You should also appropriately size images unless you want them to overlap other components on the page.

Adding a custom logo and text

Step 1 – Using putty, log in as root on vCSA, and run the following two commands.


chsh -s /bin/bash root

Step 2 – Using WinSCP, connect to vCSA and copy the logo (PNG file) to the following path.


Step 3 – Switch back to the putty window and run the following commands.

chsh -s /bin/appliancesh root
cd /usr/lib/vmware-sso/vmware-sts/webapps/websso/WEB-INF/views
cp unpentry.jsp

The first command resets the appliance back to using the default shell. We then switch to the directory of the file controlling the logon page and take a backup of it.

Step 4 – Using the vi editor, we’ll go ahead and edit unpentry.jsp. This allows us to add a custom company logo and text.

vi unpentry.jsp

Type /.png and press Enter. This takes you to the section in the file which governs what images get displayed on the login page. To add customized HTML text to the login page, scroll down to the section starting <div id=”productName”>. Add the text you want to be displayed as shown in the next screenshot. You can include HTML tags such as header size for further effect. Save the file (wq) and exit.

The Login Page CSS

You can play around with login.css style sheet to further tweak the login page. The style sheet can be found under;

  • /usr/lib/vmware-sso/vmware-sts/webapps/websso/resources/css/login.css [vCenter Appliance]
  • C:\ProgramData\VMware\vCenterServer\runtime\VMwareSTSService\webapps\websso\resources\css\login.css [Windows based vCenter]

vCenter Server for Windows

The above procedure equally applies to vCenter Server for Windows, with the process being intrinsically easier to carry out. The only significant differences are paths to the images folder, login (JSP) file, and CSS.

  • C:\ProgramData\VMware\vCenterServer\runtime\VMwareSTSService\webapps\websso\WEB-INF\views\unpentry.jsp
  • C:\ProgramData\VMware\vCenterServer\runtime\VMwareSTSService\webapps\websso\resources\img\<your_graphic>.png
  • C:\ProgramData\VMware\vCenterServer\runtime\VMwareSTSService\webapps\websso\resources\css\login.css

Just copy the logo or graphics you want included to the images folder and use something like notepad to edit unpentry.jsp applying the same changes as outlined earlier.

Operating System Corruption due to snapshot consolidation

There are some cases where due to VMware snapshot consolidation the VM disk systems get corrupted. I faced with the same issue on ESXi 6.5 environment. I researched on the issue and finally found out that this is a known issue on some VMWare versions. The symptoms are as follows;


  • Applications such as databases may report block-level data inconsistency.
  • Guest operating systems may report file system metadata inconsistencies
  • The VM fails to boot when it is running from an SEsparse snapshot. (SEsparse is a snapshot format introduced in vSphere 5.5 for large disks, and is the preferred format for all snapshots in vSphere 6.5 and above with VMFS-6)

Affected Environments:

VMFS-5 or NFS Datastores: VMs with virtual disks >2TB and snapshots. On VMFS-5 and NFS, the SEsparse format is used for virtual disks that are 2 TB or larger
VMFS-6 Datastores: VMs with snapshots. SEsparse is the default format for all snapshots on VMFS-6 datastores.

Impacted vSphere releases: vSphere 6.5 and above with VMFS-6 and any VM with snapshots | vSphere 5.5 and above when VMs with virtual disks >2TB have snapshots.

So basically if the VM size is more than 2TB in size and the VMFS versions are VMFS5 & VMFS6, there might be data corruptions on the infrastructure.

The issue has been resolved starting from the following ESXi versions;

  • vSphere 6.7 Update 1 
  • vSphere 6.5 Patch
  • vSphere 6.0 Patch

As a workaround, disabling “IO coalescing” for SEsparse can be carried out on host system level.

for more information, please refer the KB

[source: VMware Knowledge Base]