Backups Causing very high loads. Even causing server to go down.

[Legin76]

I'm using cpanels backup facility with a postcpbackup script duplicate to keep a better backup history.

In total the home directory is 27gbs. Backups take from 2am until about 9am. The weekly backups also run on Wednesdays.

It seems that twice in the last two weeks on a Wednesday morning the sever load has got so high that sites are not loading at about 7:30 to 8am. The first time it worked itself out before I managed to do anything. The second (this morning) it got to the point that I couldn't log into ssh or the whm admin. I did manage to log in to ssh briefly before it went down and rsync was showing at the top of the top. I had to put in a restart request to get the server back up.. After the restart the server was running as fast as I could hope. The backups appear to have completed too.

Is the monthly backup just a duplicate of the from that day daily backup or does it run the process a second time?

Is there a way I can make the backups start earlier but also not take up so many resources?

 

[cPanelMichael]

Hello

You can modify the following option under the "Stats and Logs" tab in "WHM Home » Server Configuration » Tweak Settings":

"Extra CPUs for server load"

Per it's description, it's the load average above the number of CPUs at which cpuwatch, cpanellogd, backups, and CPU stats consider the system to be in a critical load state. For example, a server with 4 physical CPUs and a value of 2 in this field will be considered “critical” in these cases once the load reaches 6. Backups will suspend temporarily until the load goes back below the configured threshold.

You can manually modify the time the backup script runs by editing the root crontab with a command such as:

# crontab -e

Or, you can install the "Cron Config" plugin to modify the cron job time in WHM via:

"WHM Home » cPanel » Manage Plugins"

To note, cPanel 11.38 introduces some improvements to the backup system that may interest you. You can find more information on it at:

11.38 - Improved Backup System - Release Notes

It's currently only available on the "CURRENT" and "EDGE" build tiers, so you will likely want to wait until it's pushed to the "RELEASE" build tier before upgrading.

Thank you.

 

[Legin76]

Thank you.. I've changed the "Extra CPUs for server load" from 5 to 3 and moved the backup cron forward by a couple of hours. Hopefully this will make the difference. The 11.38 changes look good. I'm sure the backup system will be much better because of it.

 

[cPanelMichael]

The following thread may also be useful if you would like to investigate your load issues further to rule out any other causes besides the backups.

Troubleshooting Load issues on Linux servers

Thank you.