JetBackup Restorations failing with: [ERROR] Server load is too high for to much time, cancelling restore process

Symptoms

You have found errors similar to the following in the JetBackup restoration logs:

[ERROR] Server load is too high. let the server cool down for 60 seconds
[ERROR] Server load is too high for to much time, cancelling restore process

The load limit shown in the log is much lower than your server's available processes. For example the limit may be set to 5, but your server has 16 cores available:

# nproc
16

Description 

JetBackup has the ability to prevent restorations from occurring if they would exceed your predefined load limit.

If the limit is set too low for your server, backups may fail prematurely. You can fix this by updating the JetBackup configuration as noted below.

How to update the configuration

1. Login to WHM as the root user

2. Navigate to: Home »Plugins »JetBackup

3. Click on the JetBackup icon in the upper left area to expand the side menu:

4. Click on the "Settings" menu item

5. Click on the "Performance" tab along the top of the JetBackup frame/page

6. Look for the "Restore Server Load Limits" option and set it to an appropriate number for your specific server. 

NOTE: The load measurement number is roughly equated to the number of cores in use on your server. Once the load measurement reaches the maximum number of cores on your server, that typically means your server's CPU resources are entirely used up. If you are not sure how many cores are available on your server, you can find that number by executing the following command via SSH or Terminal as the root user:

nproc