If you have a single node elasticsearch instance and indices with replicas enabled your cluster state will be yellow. If...
This should not be necessary in any case and is only for special cases, for e.g. if the assets...
With passenger-status --show=requests you can get a huge JSON showing current information about the running passenger processes.
If one etcd node is no longer a member of the remaining etcd cluster or fails to connect you need...
This card is just about creating simple PostgreSQL dumps. This is no instruction for a backup strategy nor a guide...
Hint This applies only to distributions based on Debian. Requirement You need to setup the PostgreSQL Apt Repository first.
on the bash (issued as postgres user) Start/Stop/Restart PostgreSQL pg_ctl -D $configdir start|stop|restart Start/Stop/Restart the corresponding PostgreSQL...
If you're trying to start a cloud-init based Ubuntu VM with KVM you will suffer long boot times...
Hint You're not able to control which redis replica will chosen for the failover. Connect to your sentinel instance...
Because systemd is the greatest thing ever it's not enough to stop the libvirt service. You need to disable...
When receiving a new SSL-Certificate for an existing SSL-key it should be checked that they match cryptographically.
You will need to look here and find your own device. Look for the "bootable CD" download, which will give...
To see all jails: fail2ban status Our $JAIL is usually ssh. To see which IPs are banned currently: fail2ban-client...
Don't use exec without user parameter If you use exec without user parameter, the command will get executed as...
If you want to perform a failover on another haproxy backend server this is the way you should do it...
If you try to restart you may encouter the problem that your networking connection gets shutdown but not start again...
Brendan Gregg is the Linux performance god. Use the information in this link to find out what ways there are...
We want to make the following firewall rule to be applyable to different network interfaces (for e.g. different environments...
The puppet server caches custom functions. If you edit an existing function (e.g. while you’re developing it), you’ll...
Sending a testmail from a server with a configured exim is easy as pie. From your usershell: tell exim that...
Bash stores the exitcodestatus of piped commands in the environment variable PIPESTATUS So you can just echo ${PIPESTATUS[@]} to get...
If you need the debug output of the puppetmaster running with passenger you have to uncomment this setting in the...
Investigate why mails are frozen The exim documentation says: Freezing occurs when a bounce message encounters a permanent failure because...
swaks is a very nice tool to test SMTP. For the most linux distributions you can easily install it with...