Hi!
I ran into the same question during an install, googled and found this thread.
I too have my own server with cpanel/whm. I understand you can switch it on within the ZC, but I plan to put up numerous ZC on the server so I might as well switch it on.
Anyway, I see people have commented off and on for a few years.... so I figured I might as well post the answer in case somebody else stumbles in.
If you have control over your server and are using cpanel/whm:
- Log into the root whm
- Go to Service Configuration >> PHP Configuration Editor
- Switch to Advance Mode
- Scroll down to: Output Control : output_buffering
- Click "On"
- Scroll to the bottom of the page and Save.
I don't know if it is better to do it at the server level or within ZC/admin as DrByte describes. But at least you won't get that "Alert" during future installations.