Apache hang for few seconds while occ preview:generate-all in operation

I’m running occ preview:generate-all and meanwhile server is not responding for a few seconds. It have happened twice far as I can tell. Is it normal? I’m running Ubuntu 18.04.1.

Preview generation is very taxing on CPU, disks and database. It isn’t odd that you experience slowdowns.

Try reducing the priority of the occ command to lessen the impact on the system.

sudo -u www nice -n19 php occ...

Tnx, ill write that command down for next time. I’m experimenting whit preview settings so I will recreate previews for sure.