Вручную апач запустился таким образом:
root@Keenetic_Giga:/home/admin# /usr/sbin/apache2 -V
[Fri Jun 23 15:01:08.963558 2017] [core:warn] [pid 6452] AH00111: Config variable ${APACHE_RUN_DIR} is not defined
apache2: Syntax error on line 80 of /etc/apache2/apache2.conf: DefaultRuntimeDir must be a valid directory, absolute or relative to ServerRoot
root@Keenetic_Giga:/home/admin# source /etc/apache2/envvars
root@Keenetic_Giga:/home/admin# /usr/sbin/apache2 -V
Server version: Apache/2.4.25 (Debian)
Server built: 2017-01-25T22:59:26
Server's Module Magic Number: 20120211:67
Server loaded: APR 1.5.2, APR-UTIL 1.5.4
Compiled using: APR 1.5.2, APR-UTIL 1.5.4
Architecture: 32-bit
Server MPM: prefork
threaded: no
forked: yes (variable process count)
Server compiled with....
-D APR_HAS_SENDFILE
-D APR_HAS_MMAP
-D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
-D APR_USE_SYSVSEM_SERIALIZE
-D APR_USE_PTHREAD_SERIALIZE
-D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
-D APR_HAS_OTHER_CHILD
-D AP_HAVE_RELIABLE_PIPED_LOGS
-D DYNAMIC_MODULE_LIMIT=256
-D HTTPD_ROOT="/etc/apache2"
-D SUEXEC_BIN="/usr/lib/apache2/suexec"
-D DEFAULT_PIDLOG="/var/run/apache2.pid"
-D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
-D DEFAULT_ERRORLOG="logs/error_log"
-D AP_TYPES_CONFIG_FILE="mime.types"
-D SERVER_CONFIG_FILE="apache2.conf"
root@Keenetic_Giga:/home/admin# service apache2 restart
[....] Restarting Apache httpd web server: apache2Invoking 'systemctl start apache2'.
Use 'systemctl status apache2' for more info.
Running in chroot, ignoring request.
failed!
[....] The apache2 instance did not start within 20 seconds. Please read the log[warns to discover problems ... (warning).
root@Keenetic_Giga:/home/admin# apache2 -k restart
httpd not running, trying to start
root@Keenetic_Giga:/home/admin#
Используя команду service apache2 restart по прежнему не запускается, куда копать?