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

last updated in Categories , , , , , ,

I have a CentOS 5 server running on Dell server hardware. I am getting the following error message in my /var/log/messages file (some time message is also display on the 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 on Linux based system?

Postfix setup catch-all email accounts using /etc/postfix/virtual

last updated in Categories , , , , ,

Q. How do I setup cacth-all email accounts under Postfix MTA? For example if an email send to me@domain.com, info@you.com and sales@you.com, should be sent to the same email address.

This is useful if anyone of user mistypes an email address when they send it to me, or just guesses at a valid email address, then they will likely get an error message from my server such as user / email mail box does not exist. So I wish to set up a “catch all” address

A. Mapping is done using /etc/postfix/virtual file.
# vi /etc/postfix/virtual
Append code as follows, replacing domain and emailusername with actual values:
@yourdomain.com emailusername

Save and close the file. Run following command:
# postmap /etc/postfix/virtual

Also make sure you have following line in /etc/postfix/main.cf file:
virtual_alias_maps = hash:/etc/postfix/virtual

If you just added above, line reload postfix:
# service postfix reload

Caution: if you set up a catch-all email address, you will likely receive more unsolicited (spam) email.

Linux Kernel panic VFS Unable to mount root fs and solution

last updated in Categories ,

Q. I am using Linux on HP server and I am getting error that read as follows:
Linux Kernel panic: VFS: Unable to mount root fs

How do I solve this problem?

A. Most modern distributions including Debian uses loadable kernel module for ext3 file system. So to read ext3/ext2 file system kernel must load ext3 kernel module (ext3.ko).

This module is included in an initrd image. If an initrd image is missing or that image does not include suitable kernel modules to access the ext3 filesystem on the partition, an error message (Linux Kernel panic: VFS: Unable to mount root fs) will be displayed to you.

To solve this problem you need to use mkinitrd script that constructs a directory structure that can serve as an initrd root file system.

The instructions for creating initrd images are here on our site.