Debian 9.1 admin-warnings despite opcache running - clarification on settings

i run nc 12.0.2 on debian 9.1 with apache, mariadb and php7 with opcache.
even though opcache is up and running with the configured params according to phpinfo() i receive warnings on the admin-page about it being configured wrong.

when setting it up i found out that this debian release does not configure it via /etc/php/7.0/*/php.ini (which the admin-page seems to read) but (exclusively) via /etc/php/7.0/mods-available/opcache.ini

i tested some settings and now use the following:

zend_extension=opcache.so
opcache.enable=1
opcache.enable_cli=1
opcache.max_accelerated_files=7963
opcache.fast_shutdown=0
opcache.memory_consumption=512
opcache.interned_strings_buffer=32
opcache.revalidate_freq=60
opcache.log_verbosity_level=1
; 0 = fatal; 1 = error, 2 = warning; 3 = info 4 = debug
opcache.error_log=/tmp/opc.log
; empty for STDERR (webserver log)
opcache.use_cwd=1
;opcache.save_comments=0
;opcache.load_comments=0
;opcache.file_cache=/tmp/op-tmp/

i looked up some values on php.net and changed some because the server has enough memory and cpu-cores to be able to handle this.

i ask the devs and others to share their views or comment on these settings.
1.
zend_extension=opcache.so
opcache.enable=1
opcache.enable_cli=1
all this has to be enabled for opache to work with apache and cli (occ, …)
2.
opcache.max_accelerated_files=7963
the nc-doc and warning suggest a value of 10.000 but php.net states: “The actual value used will be the first number in the set of prime numbers { 223, 463, 983, 1979, 3907, 7963, 16229, 32531, 65407, 130987 } that is greater than or equal to the configured value.” http://php.net/manual/en/opcache.configuration.php#ini.opcache.max-accelerated-files so 10.000 would actually set 16229. To me 7963 cached scripts seem enough for my nc-installation.
3.
opcache.fast_shutdown=0
settting this to on could lead to segfaults (i read in several places, but not on php.net)
4.
opcache.memory_consumption=512
opcache.interned_strings_buffer=32
i set this high in hope of a performance gain and because the box has enough memory
5.
opcache.revalidate_freq=60
(opcache.validate_timestamps is enabled by default)
how often to check (in seconds) if (cached) scripts (or rather, their timestamps) were changed in the filesystem. Default is 0 and means on every request: “0 will result in OPcache checking for updates on every request.” (http://php.net/manual/en/opcache.configuration.php#ini.opcache.revalidate-freq) i guess this only happens on an nc-update or if you change/write php-scripts yourself, so one minute seems sufficient for my needs. But in these cases i have to restart the webserver manually.
6.
opcache.log_verbosity_level=1
; 0 = fatal; 1 = error, 2 = warning; 3 = info 4 = debug
opcache.error_log=/tmp/opc.log
; empty for STDERR (webserver log)
the logging-stuff is just for my personal taste, it can help when debugging.
7.
opcache.use_cwd=1
appends the CWD to a script so that no mess ensues when there are scripts with the same basename in different dirs. i checked with
find /var/www/NC-WEBDIR -type f -iname “*.php” -exec basename {} ; | sort
and was certain this has to be set.
8.
;opcache.save_comments=0
;opcache.load_comments=0
load/save comments from php-code, enabled by default.
i was hoping for some performance-gains but setting this to on (1) caused nc not to run anymore at all. (the error-msg was very clear, though)
9.
;opcache.file_cache=/tmp/op-tmp/
i had hoped to improve performance by doing some file-caching but no files showed up in this dir and there was a noticeable performance loss.

maybe the code for the admin-warning (which i do not really mind if these settings are OK) and the documentation could be updated to include this stuff for debian 9.1.

Which is by the way the more elegant way, enabling plug & play settings together with the mod itself.

Yeah I would agree that the warnings about the settings expect to specific values that do not match every system/use case. Maybe there should be certain ranges accepted with link to more explanations.

Same here.