ubuntu

Please check your init.d file, are you sure your path is 'var/run/zabbix/zabbix_server.pid' instead of '/var/run/zabbix/zabbix_server.pid' (slash at beginning) ? Next step, you should check permission for this directory, zabbix user should have proper rights.

my init.d

#! /bin/sh

1. 1. 1. BEGIN INIT INFO
2. Provides: zabbix-server
3. Required-Start: $remote_fs $network
4. Required-Stop: $remote_fs
5. Default-Start: 2 3 4 5
6. Default-Stop: 0 1 6
7. Should-Start: mysql
8. Should-Stop: mysql
9. Short-Description: Start zabbix-server daemon
   1. 1. END INIT INFO

set -e

NAME=zabbix_server
DAEMON=/usr/sbin/$NAME
DESC="Zabbix server"

test -x $DAEMON || exit 0

DIR=/var/run/zabbix
PID=$DIR/$NAME.pid
RETRY=15

my zabbix_server.conf

1. 1. 1. Option: PidFile
2. Name of PID file.
   #
3. Mandatory: no
4. Default:
5. PidFile=/tmp/zabbix_server.pid

PidFile=/var/run/zabbix/zabbix_server.pid

drwxr-xr-x 2 zabbix zabbix 100 Aug 3 14:41 zabbix
proper rights on reserve identical proper rights on main server

paste your zabbix_server.conf file here, probably there is something wrong with your configuration and zabbix_server is not starting

Configuration seems to be OK. How did you clone zabbix to reserve server?

I cloned Zabbix with VMWare VSphere.
I have virtual server - made full clone of Zabbix vurtual machine with all configs, DB, setting, etc.
Then started .vmx file and on reserve server.
Me and my colleagues do it almost every month with other servers and systems, so I didn't expect any problems.

In the issue description there is the following suspicious output:

No process in pidfile 'var/run/zabbix/zabbix_server.pid' Found running; none killed. [OK]

There is no "/" before "var". I would expect it to be "/var/run/zabbix/zabbix_server.pid". Could you please check whether fixing it makes a difference?

My mistake
server respons this message with "/"

No process in pidfile '/var/run/zabbix/zabbix_server.pid' Found running; none killed. [OK]

Important detail

After "service zabbix-server restart" ON MAIN SERVER
I have same mistake No process in PID file!!!

when I type "bash -x zabbix-server restart" I have this message:
zabbix-server: line 57: zabbix-server: command not found

My /etc/init.d/zabbix-server script

#! /bin/sh

1. 1. 1. BEGIN INIT INFO
2. Provides: zabbix-server
3. Required-Start: $remote_fs $network
4. Required-Stop: $remote_fs
5. Default-Start: 2 3 4 5
6. Default-Stop: 0 1 6
7. Should-Start: mysql
8. Should-Stop: mysql
9. Short-Description: Start zabbix-server daemon
   1. 1. END INIT INFO

set -e

NAME=zabbix_server
DAEMON=/usr/sbin/$NAME
DESC="Zabbix server"

test -x $DAEMON || exit 0

DIR=/var/run/zabbix
PID=$DIR/$NAME.pid
RETRY=15

if test ! -d "$DIR"; then
mkdir "$DIR"
chown -R zabbix:zabbix "$DIR"
fi

export PATH="${PATH:+$PATH:}/usr/sbin:/sbin"

1. define LSB log_* functions.
   . /lib/lsb/init-functions

case "$1" in
start)
log_daemon_msg "Starting $DESC" "$NAME"
start-stop-daemon --oknodo --start --pidfile $PID \
--exec $DAEMON >/dev/null 2>&1
case "$?" in
0) log_end_msg 0 ;;
*) log_end_msg 1; exit 1 ;;
esac
;;
stop)
log_daemon_msg "Stopping $DESC" "$NAME"
start-stop-daemon --oknodo --stop --pidfile $PID --retry $RETRY
case "$?" in
0) log_end_msg 0 ;;
*) log_end_msg 1; exit 1 ;;
esac
;;
status)
status_of_proc "$DAEMON" "$NAME" && exit 0 || exit $?
;;
restart|force-reload)
$0 stop
$0 start
;;
*)
echo "Usage: /etc/init.d/$NAME

" >&2
exit 1
;;
esac

exit 0

I fixed this problem
When I execute /etc/init.d/zabbix-server/ Line
" start-stop-daemon --oknodo --start --pidfile $PID \
--exec $DAEMON >/dev/null 2>&1"
there is message "Unknown parametr DisableHouseKeeping = 1"
after commenting DisableHouseKeeping = 1 in zabbix_server.conf everything works fine/

as a reminder, please do use channels, listed at https://zabbix.org/wiki/Getting_help , for support