Articles by Falko Timme
Author: Falko Timme • Tags: other, shell • Comments: 6 • Updated: May 15, 2020
To edit files on the command line, you can use an editor such as vi. To open the file, run vi /path/to/file Now you see the contents of the file (if there is any. Please note that the file is created if it does not exist yet.). The most important commands in vi are these: Press i to enter the Insert mode. Now you can type in your text. To leave the Insert mode press ESC.
Author: Falko Timme • Tags: linux, security • Comments: 19 • Updated: May 08, 2020
Sometimes you need to destroy or wipe data from hard drives (for example, before you sell your old hard drives on eBay) so that nobody else can access them. Simply deleting data (e.g. with rm) is not enough because that just removes the file system pointer, but not the data, so it can easily be undeleted with recovery software. Even zero'ing out your hard drive might not be enough. Here's where shred comes into play - shred can overwrite the files and partitions repeatedly, in order to make it harder for even very expensive hardware probing to recover the data.
Author: Falko Timme • Tags: linux • Comments: 0 • Updated: Dec 27, 2019
Sometimes you need to move a web site from one server to another. Instead of downloading the web site from the old server to your PC via FTP and uploading it from your PC to the new server, it would save a lot of time to simply copy the web site from one server to the other. This tutorial explains how to use Wget to download/move a web site from one server to the other via FTP.
Author: Falko Timme • Tags: email • Comments: 31 • Updated: Sep 13, 2019
How To Migrate Mailboxes Between IMAP Servers With imapsync- This guide explains how you can migrate mailboxes between IMAP servers with imapsync. imapsync is an IMAP synchronisation, sync, copy or migration tool. More than 32 different IMAP server softwares are supported with success. All flags are preserved, unread will stay unread, read will stay read, deleted will stay deleted.
Author: Falko Timme • Tags: errors • Comments: 1 • Updated: Aug 05, 2019
Error: Postfix - virtual_mailbox_limit is smaller than message_size_limit You get the following error in your mail log: Jul 13 17:12:30 mail postfix/virtual: fatal: main.cf configuration error: virtual_mailbox_limit is smaller than message_size_limit
Author: Falko Timme • Tags: postfix • Comments: 5 • Updated: Jul 01, 2019
This short tutorial will show you how to get the version number of the Postfix email server.
Author: Falko Timme • Tags: linux, other • Comments: 17 • Updated: Mar 28, 2019
Linux screen Command: Keep Your Processes Running Despite A Dropped Connection I guess you all know this: you are connected to your server with SSH and in the middle of compiling some software (e.g. a new kernel) or doing some other task which takes lots of time, and suddenly your connection drops for some reason, and you lose your labour.
Author: Falko Timme • Tags: mysql • Comments: 27 • Updated: Mar 20, 2019
If you have set up MySQL replication, you probably know this problem: sometimes there are invalid MySQL queries which cause the replication to not work anymore. In this short guide, I explain how you can repair the replication on the MySQL slave without the need to set it up from scratch again.
Author: Falko Timme •
Tags: backup, debian, linux, ubuntu •
Comments: 43 •
Updated: Aug 06, 2018
This tutorial shows how you can mirror your web site from your main web server to a backup server that can take over if the main server fails. We use the tool rsync for this, and we make it run through a cron job that checks every x minutes if there is something to update on the mirror. Thus your backup server should usually be up to date if it has to take over.
Author: Falko Timme •
Tags: debian, shell, ubuntu •
This guide shows how you can check the dependencies of a package with the tool apt-rdepends on Debian and Ubuntu systems. The great thing about apt-rdepends is that it resolves dependencies recursively, i.e., not only does it show the direct dependencies of a package, but also the dependencies' dependencies. This is great, for example, if you want to rebuild a package from the sources, etc.