---
title: "Reverting the Grid to a Previously Running Software Version"
canonical: "https://docs.infoblox.com/space/niosupgrade/1321042008/Reverting%20the%20Grid%20to%20a%20Previously%20Running%20Software%20Version"
format: markdown
---
You can revert the Grid to a version of software that was previously running on your NIOS appliance. 

> ⚠️ Reverting the Grid will cause the entire Grid to restart instantly.

The NIOS appliance stores the previous software version in its backup software partition. You can see if there is a software version to which you can revert and its version number in the Alternate Version column in the Grid Version Information section of the **Upgrade** tab. To view the software version, from the **Grid** tab, select the **Upgrade** tab. Note that once you start distributing a new NIOS version after an upgrade, you cannot revert to a previous NIOS version.  
Be aware that when you revert to this software, changes made since the Grid was last upgraded are lost, including the new DHCP leases and other DNS changes.  
To revert to a version of software previously running on a Grid or on an independent appliance or HA pair:

- From the **Grid** tab, select the **Upgrade** tab, and then click **Revert** -> **Revert** **Grid** from the Toolbar.

The entire Grid will restart instantly, and Grid Manager will display a warning indicating that the revert process disrupts Grid services. Read the warning carefully, and then click **Yes** to confirm your decision to revert.

## Stuck at Kernel Reboot

Sometimes, if you run the `set vpn_comm block` CLI command, non-distributed Grid members that are auto-synchronized do not come up as online after a Grid revert and remain stuck at the kernel reboot phase (“Booting the Kernel” stage on the CLI console).

This is because when the `set vpn_comm block` CLI command occurs during the distribution phase and a Grid member is skipped, the member is marked as offline, and the process continues with its status updated accordingly.

This is a rare scenario. If the skipped Grid member subsequently rejoins the grid during this state, it is considered an invalid operation. As a result, the Grid member may proceed with the auto-synchronization after the Grid Master is upgraded, even though it does not have a valid alternate NIOS version available.