Submitted by newburns on Wed, 11/01/2017 - 13:33
I am able to create a let's encrypt certificates for 18 domains and virtual aliases pointing to my WordPress Multisite. When I add 20 or more, the process seems to hang. No errors, just running. I can see the letsencrypt.cgi process running in top for 2 days now. Also, the last renewal was 0.54 months ago. So Let's Encrypt cert process is working just fine, but trying for 20 or more hangs.
Given what you said, If I did not misunderstand your question, here is my case/situation. On one machine, I have 32 virtual servers; 27 out of which have SSL enabled.
All SSL certificates for valid domains are automatically renewed by Lets Encrypt. My point: number is not a problem for Lets Encrypt.
It probably has something to do with your server's hard disk space, processor speed, or availability of RAM.