Howto's and FAQ's

Rotating MySQL slow query log


On MySQL servers with slow query log enabled the log file might grow excessively when having a high volume of slow queries, the same might happen with the general mysql log file.
Simply deleting the log file might cause downtime while it might take a long time to perform the deletion of the log file (depends on the log file size and filesystem)
There is safeway way to rotate the slow query log files without stopping the mysqld daemon or blocking MySql during a truncate.


ssh CTRL + s recovery


If you use CTRL + s (software flow control or XOFF/XON flow control) during a ssh session your terminal seems to stop responding to any keystroke.
However, the terminal is still connected, by typing CTRL + s you sent XOFF, meaning transmit off, which pauzes the transmission. CTRL + q, XON, resumes the transmission.
Keep in mind that everything you type after CTRL + s is buffered and will be sent when you resume the transmission with CTRL + q.


Iomega IX2 (and other NAS devices) making read-only partitions writable

One of the disadvantages of the Iomega IX2-200 NAS device is that once you want to startup a daemon on startup of want to modify settings which you cant modify by the webinterface, you need to gain access the the shell, edit the neccessary config files or startup scripts, but you face the fact that the partitions are read-only or even if the config file is stored on a writable partition, the modification is not persistant while it will be over written at the next reboot. To solve this you need to make the read-only partition writable.

Difference between mtime, ctime and atime

A common mistake is that ctime is the file creation time. This is not correct, it is the inode/file change time. mtime is the file modification time. A often heard question is "What is the ctime, mtime and atime?".This is confusing so let me explain the difference between ctime, mtime and atime.

Yum check or install only security updates


With yum you are able to check for or install only necessary security relevant updates. You need to install the security plugin.

yum install yum-security

Thereafter you can check for security updates;

yum --security check-updates

or update only security relevant updates;

yum --security update

Create your own 'DropBox' with Apache and WebDAV

Create your own cloud with Apache and WebDAV, a good alternative for online cloud services like Dropbox, Google Drive and others.

WebDAV is an extension to the HTTP protocol and allows collaboratively manage files on webservers and it is easy to setup.

If not already installed, install Apache.
  • «
  •  Start 
  •  Prev 
  •  1 
  •  2 
  •  3 
  •  4 
  •  5 
  •  6 
  •  7 
  •  8 
  •  9 
  •  Next 
  •  End 
  • »
Page 1 of 9


You are here: Home Howtos and FAQs