> Source: [sk181989](https://support.checkpoint.com/results/sk/sk181989)

# sk181989 - High core count Security Gateway in Kernel Mode Firewall fails to boot after the Jumbo Hotfix Accumulator upgrade

| Property | Value |
|----------|-------|
| Solution ID | sk181989 |
| Date Created | 2024-02-05 |
| Last Modified | 2024-03-18 |
| Technical Level | General |
| Products | Cloud Firewall |
| Versions | R81.20 |

## Symptoms

- * Security Gateway boots into Maintenance mode after the Jumbo Hotfix Accumulator upgrade to R81.20 Take 43/ Take 45.
* There is a "*CKP: Loading FW-1 IPv4 Instance N: \[FAILED\]*" message in the console logs.

## Cause

The Firewall instance size has surpassed the permitted limit set by the Linux Kernel, preventing additional instances from loading.

## Solution

**Follow these steps** to resolve the issue:  

Revert Jumbo Hotfix Accumulator R81.20 Take 43/ Take 45 and upgrade to R81.20 Take 53:

1. Log in to the Security Gateway to Maintenance mode.
2. Edit the file at *$FWDIR/boot/boot.conf* file in theVisual Editor.
3. Adjust the value of KERN_INSTANCE_NUM to a number lower than 40, preferably 30.
4. Save the *$FWDIR/boot/boot.conf* file.
5. Reboot the system.
6. Uninstall the current Jumbo Hotfix Accumulator.
7. Reboot the Security Gateway.
8. Edit the file at *$FWDIR/boot/boot.conf* file in the Visual Editor again.
9. Save the *$FWDIR/boot/boot.conf* file.
10. Restore the value of KERN_INSTANCE_NUM to 40.
11. Reboot the Security Gateway.

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