Archive | August, 2011

Kernel panic

25 Aug
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block

On RHEL 6.

This might happen when a yum update is interrupted. You can try booting into any other kernel you have and running:


Otherwise reinstall your kernel-xx and kernel-firmware-xx packages.




Perl – CPAN – auto yes to all dependencies

25 Aug
$> cpan
cpan> o conf prerequisites_policy follow
cpan> o conf commit
cpan> exit

sudo – PATH/$PATH changes

22 Aug

Pretty annoying, do this to fix:

alias sudo='sudo env PATH=$PATH'

cp all files including hidden or dot files

19 Aug

doing this will not copy . files or directories (e.g. .screenrc, .bashrc, .ssh)

cp -r /var/x/* /y/

you need to do this first:

shopt -s dotglob

When you're finished do this:

shopt -u dotglob

Perl – copying modules from one machine to another – upgrading

18 Aug

Do this as root.

Run this on your old/source machine:

bash perl -MCPAN -e autobundle

it will create something like /root/.cpan/Bundle/

copy this file to your new machine (in /root/.cpan/Bundle) and run:

perl -MCPAN -e 'install Bundle::Snapshot_xxx'

Perl – list all installed modules

18 Aug

From command line, as root:

perl -MCPAN -e 'print CPAN::Shell->r '

Dell 2950 – which generation do I have? Gen I, Gen II, Gen III

11 Aug

Finding this out is more difficult than it should be. Apparently the Generation III’s use 54xx processors.. you can check:

cat /proc/cpuinfo

This suggested that it was a Generation III, but I wanted to know for sure.

I used OpenManage to find:

1. Need to start OpenManage –

    /opt/dell/srvadmin/sbin/ start

2. Now go to https://localhost:1311. You can use normal user credentials.

3. Navigate to System->Main System Chassis->Information (tab).

4. Read the “System Revision”