
Dec 16, 2014
As Debian big fan, sometime I found that apt-get update command reveal this error:
“E: Some index files failed to download. They have been ignored, or old ones used instead.”
This command is very simple solution I found:
# rm /var/lib/apt/lists/partial/*
After that, apt-get update && apt-get upgrade command should be fine.
Source:
– http://forums.debian.net/viewtopic.php?f=10&t=108618

Dec 6, 2014
/boot Partition in CentOS 6 can be cleaned by removing old kernels.
These are the steps:
1. Check /boot partition (98% used)
# df -h
Filesystem Size Used Avail Use% Mounted on
...
/dev/sda1 93M 86M 2.1M 98% /boot
...
2. Check installed kernel
# rpm -q kernel
kernel-2.6.32-431.el6.x86_64
kernel-2.6.32-431.29.2.el6.x86_64
kernel-2.6.32-504.1.3.el6.x86_64
3. Install package-cleanup
# yum install yum-utils
# package-cleanup --oldkernels --count=2
=======================================================================================================================================
Package Arch Version Repository Size
=======================================================================================================================================
Removing:
kernel x86_64 2.6.32-431.el6 @anaconda-CentOS-201311272149.x86_64/6.5 121 M
Transaction Summary
=======================================================================================================================================
Remove 1 Package(s)
Installed size: 121 M
Is this ok [y/N]: y
Downloading Packages:
Running rpm_check_debug
Running Transaction Test
Transaction Test Succeeded
Running Transaction
Erasing : kernel-2.6.32-431.el6.x86_64 1/1
Verifying : kernel-2.6.32-431.el6.x86_64 1/1
Removed:
kernel.x86_64 0:2.6.32-431.el6
Complete!
4. Check /boot partition (67% used)
# df -h
Filesystem Size Used Avail Use% Mounted on
...
/dev/sda1 93M 59M 30M 67% /boot
...
5. Limit only 2 latest kernel for later updates
# vim /etc/yum.conf
...[edit yum.conf]...
installonly_limit=2
...[edit yum.conf]...
Source:
– http://www.if-not-true-then-false.com/2012/delete-remove-old-kernels-on-fedora-centos-red-hat-rhel/

Dec 1, 2014
Having several Linux Servers, SSH access is mandatory communication between me and those servers. These are several tips for SSH Server administration that save the day:
Add these line on /etc/ssh/sshd_config:
Make sure to restart SSH service after changing sshd_config:
# service ssh restart
or
# /etc/init.d/ssh restart
Additional tip:
- Add this options on /etc/resolv.conf (solving slow login respond on RHEL/CentOS)
options single-request-reopen
Source:
– http://injustfiveminutes.com/2013/03/13/fixing-ssh-login-long-delay/