Can't start MongoDB on CentOS7 - mongodb

Question

I have a CentOS 7 empty VM.
> hostnamectl
...
Operating System: CentOS Linux 7 (Core)
CPE OS Name: cpe:/o:centos:centos:7
Kernel: Linux 3.18.26-guest-4-4751b4a-x86_64
Architecture: x86_64
I've installed MongoDB.
> mongod --version
db version v3.0.11
git version: 48f8b49dc30cc2485c6c1f3db31b723258fcbf39
The config file:
> cat /etc/mongod.conf
# mongod.conf
# for documentation of all options, see:
# http://docs.mongodb.org/manual/reference/configuration-options/
# where to write logging data.
systemLog:
destination: file
logAppend: true
path: /mongo/logs #/var/log/mongodb/mongod.log
# Where and how to store data.
storage:
dbPath: /mongo/data # (default) /var/lib/mongo
journal:
enabled: true
# engine:
# mmapv1:
# wiredTiger:
# how the process runs
processManagement:
fork: true # fork and run in background
pidFilePath: /var/run/mongodb/mongod.pid # location of pidfile
# network interfaces
net:
port: 27017
bindIp: 127.0.0.1 # Listen to local interface only, comment to listen on all interfaces.
#security:
#operationProfiling:
#replication:
#sharding:
## Enterprise-Only Options
#auditLog:
#snmp:
When I try to start I get this error:
> service mongod start
Starting mongod (via systemctl): Job for mongod.service failed. See 'systemctl status mongod.service' and 'journalctl -xn' for details
and:
> journalctl -xn
-- Subject: Unit mongod.service has begun with start-up
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mongod.service has begun starting up.
avril 02 14:03:06 keystone runuser[30886]: pam_unix(runuser:session): session opened for user mongod by (uid=0)
avril 02 14:03:06 keystone runuser[30886]: pam_unix(runuser:session): session closed for user mongod
avril 02 14:03:06 keystone mongod[30879]: Starting mongod: [FAILED]
avril 02 14:03:06 keystone systemd[1]: mongod.service: control process exited, code=exited status=1
avril 02 14:03:06 keystone systemd[1]: Failed to start SYSV: Mongo is a scalable, document-oriented database..
-- Subject: Unit mongod.service has failed
-- Defined-By: systemd
-- Support: http://lists.freedesktop.org/mailman/listinfo/systemd-devel
--
-- Unit mongod.service has failed.
--
-- The result is failed.
avril 02 14:03:06 keystone systemd[1]: Unit mongod.service entered failed state.
Has anyone encountered the issue "Failed to start SYSV"?
Any help or hint is welcome.
Thanks, Paul

Answer 1

The root issue is selinux permissions, which is enabled by default in CentOS 7. This can be fixed by disabling selinux or adding the correct context to the mongo database path:
chcon -R -t mongod_var_lib_t /var/lib/mongod