Category: Tips & Tricks

Error: Can’t open display: localhost:10.0

February 4, 2015 Emil C
1 Comment
I use X Forwarging over SSH for several things to manage, such as virtual machines with “virt-manager”. Today, when I wanted to run a graphical tool on one of the servers I kept getting this error. Error: Can't open display: localhost:10.0 I verified all the possible configurations issued, launched the…
Tips & Tricks

follow the logs

August 29, 2014 Emil C
No Comments
Well, on a high-traffic mail server we need to follow the server log, to look for possible issues. The “tail -f” method might just not be as good as we would want, text is going up too fast and web just can’t read that fast. A solution to that is…
Tips & Tricks

Per site custom CSS

August 7, 2014 Emil C
No Comments
Let’s say you’re on a news website for instance bbc.co.uk, that you read a lot, but each time you look on the website you can’t tell if you already visited that portion of the website or not. Let’s say you still have a chance, there’s a Firefox and Chrome add-on…
Tips & Tricks

MySQL requires maintenance

May 4, 2014 Emil C
No Comments
Even if you’re running on a tiny VPS or on a huge server when you have a LAMP stack your biggest memory consumer will probably be MySQL. Some even prefer running it on a different machine when it comes to high traffic web apps. But, as your apps are put…
Tips & Tricks

modern days aliases

February 11, 2014 Emil C
No Comments
Asuming we have on a mail server(that hosts domain1.com) some external aliases, like user1@domain1.com has an alias for user1@domain2.com, which is hosted on a different server, probably on a different mail provider. Typically when a mail is sent to user1@domain1.com, it’s sender’s mail server sends the mail to the MX…
Tips & Tricks

OpenVPN and Android

October 28, 2013 Emil C
4 Comments
To be honest I use OpenVPN quite rarely on my Android tablet, and it happens only when I need to access certain locations that tie me to a certain IP address. This type of connection could be more often used when the tabled would serve as an email reading device…
Tips & Tricks

TIP: Make Postfix use less SQL connections

August 9, 2013 Emil C
No Comments
When you manage Postfix mail servers using SQL connections to find informations about usernames, mailbox/maildir locations on the disk you probably have in your main.cf something like : virtual_alias_maps = mysql:/etc/postfix/mysql_virtual_alias_maps.cf virtual_mailbox_domains = mysql:/etc/postfix/mysql_virtual_domains_maps.cf virtual_mailbox_maps = mysql:/etc/postfix/mysql_virtual_mailbox_maps.cf relay_domains = mysql:/etc/postfix/mysql_relay_domains_maps.cf But, this way, each process(postfix process) uses one MySQL connection.…
Tips & Tricks