How High Can I Increase pm.max_children?

[DZMM]

What's a safe number to increase pm.max_children to on a 64GB server?  I'm getting lots of the following error with it set at 20:

Highlander php-fpm[14356]: [WARNING] [pool www] server reached max_children setting (20), consider raising it

From, this old post it looks like @limetech increased this from 5 to 10 so I'm guessing a recent update pushed this to 20.  I found another thread saying even 10 was low on a above-basic system, so how far can I hike this up?

 

 

My machine has been a bit sluggish over the last couple of days, even though memory and CPU usage are usually <50%.  The only major changes I've made is to my rclone setup and pre-clearing a replacement drive.  I've been low on disk space because of being down one drive, so maybe this has been slowing the server down as well. 

 

Thanks

 

Edit: updated diagnostics after system GUI freeze just after posting

 

Oct 16 21:20:48 Highlander kernel: comskip[23728]: segfault at 8c ip 0000152f229f2fce sp 00007ffe26c4f590 error 4 in ld-musl-x86_64.so.1[152f229aa000+8d000]

 

highlander-diagnostics-20181016-2137.zip

Edited October 16, 2018 by DZMM
updated diagnostics