Tip of the day

You need to verify that that downloaded Linux DVD or ISO images are intact before you burn and use them. This is security feature. But how do you verify ISO images? Answer is quite simple use md5sum command to compute and check MD5 message digest. Why verify ISO images? a) To protect yourself b) Verify […]


If rpm / yum command hangs during operations or you see error messages – it means your rpm database corrupted. /var/lib/rpm/ stores rpm database just delete the same and rebuild rpm database: Command to rebuild rpm database rm -f /var/lib/rpm/__db* rpm –rebuilddb Read rpm / yum man pages for more information


Bash / CSH shell offers command history feature. Most of you may be aware and using of UP / DOWN arrow keys to recall previous commands. History expansions introduce words from the history list into the input stream, making it easy to repeat commands, insert the arguments to a previous ommand into the current input […]


If you are running Dell PowerEdge 2950 server or HP ProLiant BL480c G1 server and upgraded from old version to latest Red Hat Enterprise Linux ES release 4.5 (Nahant Update 5) you will notice that ordering of your NIC devices changed. Fix problem before upgrade: Before running upgrade via up2date command open /etc/sysconfig/network-scripts/ifcfg-eth0 file (for […]


In some situation you may want to avoid loading a Linux driver module automatically . For example: [a] You would like to use proprietary device driver (I’m against any sort of proprietary drivers) and not inbuilt (reverse engineer) kernel driver. [b] If your server system connected without a diskette / floppy drive; kernel will try […]


Let us say your have a long directory name called “A_VERY_ VERY LONG_ DIRECTORY_NAME_TO_ TYPE _ A _ B _C”… So how do you change to a directory, which is having very long name without typing full name? Simply use a wildcard character called * as follows $ cd A_VERY_VERY* Or type cd A_VERY and […]


/etc/shadow stores actual password in encrypted format for user’s account with additional properties related to user password. The password expiration information for a user is contained in the last 6 fields. Password expiration for a select user can be disabled by editing the /etc/shadow file However I recommend using chage command. The chage command changes […]