Featured »

March 2, 2022 – 2:00 pm

Books have been written on the subject of awk and sed. Here’s a small sample of commands I put together over the years that are useful for everyday system administration tasks. Most of these tasks …

Read the full story »
Networking

Unix and Linux network configuration. Multiple network interfaces. Bridged NICs. High-availability network configurations.

Applications

Reviews of latest Unix and Linux software. Helpful tips for application support admins. Automating application support.

Data

Disk partitioning, filesystems, directories, and files. Volume management, logical volumes, HA filesystems. Backups and disaster recovery.

Monitoring

Distributed server monitoring. Server performance and capacity planning. Monitoring applications, network status and user activity.

Commands & Shells

Cool Unix shell commands and options. Command-line tools and application. Things every Unix sysadmin needs to know.

Home » Archive by Tags

Articles tagged with: chmod

Numeric File Permissions in Unix

June 27, 2009 – 7:50 pm
shell_001

Suppose you are working with a Web server and your task is to make sure that no files or directories have permissions “777”. It would be easy to just recursively change permissions for all files …

Duplicating WordPress Installation

June 25, 2009 – 2:51 pm
wordpress_logo

Whenever you upgrade your WordPress installation or do development work, it is always a good idea to be working on a copy of your main site and not on the real thing. Copying WordPress installation …

WordPress Directory Listing Risk

June 11, 2009 – 11:36 pm
wordpress_0004

A large number of WordPress directories do not have an index file. This is particularly dangerous in case of the plugins directory. If your server allows directory listings, a potential attacker may see which plugins …

Linux and High I/O Wait

December 21, 2008 – 12:07 am
network_cable_01

When you look at the CPU activity of your computer, one of the parameters is the iowait. This value shows how much time your CPU wastes while it is waiting for I/O operations for complete. …

Sharing Videos from Linux to Xbox 360

December 19, 2008 – 8:49 pm
old film projector with dramatic lighting

Xbox 360 uses UPnP protocol to stream multimedia files from computers on your home network. Normally, you would have a Windows PC running WMP and sharing files. But what if you have a Linux box …

Mountpoint permission problem in Solaris

May 4, 2006 – 6:45 pm
sun_solaris_0002

The following condition was originally discovered in OpenSolaris 11 (Bug ID: 4697677). This problem occurs when you do mkdir -m 700 on a mountpoint before mounting it. This superceeds whatever permissions you might give to …