≡ Menu

redhat

Linux: AMD Phenom II and AMD Athlon II CPU Change Frequency On All Logical Cores

I’ve AMD Athlon II processors based server and it does not change frequency on all logical cores under CentOS version 5.5 or RHEL Linux. How do I fix this problem?
[click to continue…]

Sysadmin because even developers need heroes!!!

Redhat / CentOS: ImageMagick Installation

How do I install ImageMagick under CentOS / Fedora / RHEL / Redhat Linux for displaying and manipulating images via perl, php, blog and other web based apps?
[click to continue…]

Existing lock /var/run/yum.pid: another copy is running as pid 523.

I‘m running the command yum update -y and getting the following error:

Loaded plugins: fastestmirror, priorities
Existing lock /var/run/yum.pid: another copy is running as pid 523.
Another app is currently holding the yum lock; waiting for it to exit…

The other application is: yum-updatesd-he
Memory : 14 M RSS ( 26 MB VSZ)
Started: Tue Feb 9 08:19:02 2010 – 14 day(s) 11:47:39 ago
State : Sleeping, pid: 523
Another app is currently holding the yum lock; waiting for it to exit…
The other application is: yum-updatesd-he
Memory : 14 M RSS ( 26 MB VSZ)
Started: Tue Feb 9 08:19:02 2010 – 14 day(s) 11:47:41 ago
State : Sleeping, pid: 523

How do I fix this problem?
[click to continue…]

Apache: Graceful Server Reboot From Shell

How do I gracefully restart Apache web server from a shell prompt?
[click to continue…]

Update Centos Linux

How do I update Centos Linux 5 software and apply security patches?
[click to continue…]

Red Hat / CentOS Linux: Enable and Install Media, CD / DVD, Moive MP3 Players

Q. How do I enable and install Media player under CentOS or Fedora or Red Hat Enterprise Linux systems? How do I play mp3s under RHEL / CentOS Linux 5.x? How do I play CD / DVD movies under RHEL / CentOS Linux version 5.x?
[click to continue…]

Linux: pathmunge Command in Shell Script

Q. I see pathmunge used in few scripts under Red Hat Enterprise Linux. Can you explain the use of pathmunge under RHEL / CentOS / Fedora Linux?
[click to continue…]

Force yum update Command To Exclude Certain Packages

How can I exclude selected packages when I rum yum update command under CentOS / RHEL / Fedora / Red Hat Enterprise Linux server?
[click to continue…]

kpartx: Linux Create Device Maps From Partition Tables ( mpath devices for partitions )

Q. How can I create mpath devices for partitions under CentOS Linux 5?
[click to continue…]

Buffer I/O error on device fd0, logical block 0 error and simply soultion

Q. I’ve CentOS 5 server running on Dell hardware. I’m getting following error message in my /var/log/message file (some time message is also shown on console):

Jul 05 12:04:05 dell01 kernel: end_request: I/O error, dev fd0, sector 0
Jul 05 12:04:05 dell01 kernel: Buffer I/O error on device fd0, logical block 0
Jul 05 12:04:18 dell01 kernel: end_request: I/O error, dev fd0, sector 0
Jul 05 12:04:18 dell01 kernel: Buffer I/O error on device fd0, logical block 0
Jul 05 12:04:30 dell01 kernel: end_request: I/O error, dev fd0, sector 0
Jul 05 12:04:42 dell01 kernel: end_request: I/O error, dev fd0, sector 0

What do they mean? How do I fix this problem?

A. This message appears when you don’t have a floppy drive attached to Linux server. Solution is quite simple just disable driver for floppy and reboot the system. You can verify this with the following command (this solution works with RHEL, CentOS, Redhat, Ubuntu/Debian and other Linux distros) :
# lsmod | grep -i floppy
Output:

floppy                 95465  0

Open file called /etc/modprobe.d/blacklist:
# vi /etc/modprobe.d/blacklist
Listing a module (driver name) in this file prevents the hotplug scripts from loading it. Usually that’d be so that some other driver will bind it instead,
no matter which driver happens to get probed first. Sometimes user mode tools can also control driver binding. Append following line:
blacklist floppy
Save and close the file. Now reboot the Linux server:
# reboot