Sending email in Linux is pretty straight forward, once an email server is set up. Just use mutt or mail and all is good. But sometimes you actually want to test if SMTP is working correctly. And not only on your box, but on a remote box. That is of course easy using a MUA […]
After moving a server to a new machine with Ubuntu 16.10 I received some strange Postfix SMTP errors. Which turned out to be a connection issue to the MySQL server: postfix/cleanup[30475]: warning: connect to mysql server 127.0.0.1: Too many connections Oops, did I forgot to up max_connections during the migration: # grep max_connections /etc/mysql/mysql.conf.d/mysqld.cnf max_connections […]
It was that time of the year, when I had to renew some SSL certificates. Renewing and updating them in the server is a nice and easy process. But checking, whether the server is delivering the correct certificate and, that I updated and popluated the intermediate certificates correctly, is a different story. For websites it […]
While debugging my check disk problem after the 15.10 upgrade, I saw that I forgot to enable external commands. That is handy, when you want to re-schedule a check to see, if your changes took effect. Again, something that is easily activated. So if you see something like this, then you might want to make […]
Another day another foo, this time done to the check_disk plugin for Nagios on Ubuntu. After updating to 15.10 my disk space check all of a sudden failed with this one here: DISK CRITICAL – /sys/kernel/debug/tracing is not accessible: Permission denied It seemed a little odd, especially when I could access that file normally before. […]
Cleaning up old kernel images on a Ubuntu machine is a quite annoying task. If you forget it and you have a separate /boot partition, then you will sooner or later run out of disk space. And then of course all your updates will fail. Doing the clean up manually is, as mentioned, more than […]
The last Chrome update and one of the last Thunderbird updates caused some strange crashes of either on of them on my Ubuntu 13.10. All is fine, it runs great and all of a sudden *boom*, browser window gone, or email client gone. Luckily .xsession-errors exists and there I could find some entries like this: […]
It feels like Groundhog Day all over again. After finding a relatively painless way of installing the PS3 Media Server on Ubuntu (PS3 Media Server And Ubuntu Foo), I found an easy way with a PPA (PS3 Media Server made easy) and I thought all will be good when I do the re-install of my […]
After doing some updates to my DNS set up I ran some standard checks. And it took me a while to realize that for some reason my zone didn’t load correctly and the secondary server was used. So I dove into the logs and low and behold I saw this: zone dusares.com/IN: journal rollforward failed: […]
Changing the configuration of a VPN can have interesting side effects. In my case I had to open up the host permissions for my MySQL users and databases from a /24 to a /16 network. Should be easy… and it actually is. Here are the SQL commands you have to execute to perform such an […]