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Grub2, problem booting after kernel update

Written by config on . Posted in Linux, Ubuntu

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If you are using grub2 ( arch linux or ubuntu 9.10 karmic koala ) you might notice some problems after kernel updates.

Symptoms – System won’t boot and you will get error similar to this:

Error – you need to load the linux kernel first.

Quick solution would be to boot from Arch / Ubuntu CD and go to recovery, mount your boot partition and get root shell ( You usually got all this in Ubuntu recovery menus, in Arch you might wanna use the shell 😉 . Go to /boot/grub and edit device.map ( what probably went wrong is that your hdd definition changed in this file and its currently trying to boot from wrong drive ). In my case changing /dev/sda to /dev/sdb  solved the problem. Do not forget to run update-grub2 to re create grub.cfg and reboot. Your system should boot as usual 🙂

Ubuntu 9.10 Karmic Koala Alpha – Ctrl+c in ssh terminal

Written by config on . Posted in Linux, Ubuntu

Seems like Ubuntu dev folks decided to change some functionality of the Ctrl-c shortcut so now it is copy function instead of break.

Anyway there is a bug open here: https://bugs.launchpad.net/ubuntu/+bug/402973

My install is ( lsb_release -a ):

Description:    Ubuntu karmic (development branch)
Release:        9.10

uname -a ( date and time stripped )

Linux psy-srv 2.6.31-3-generic-pae #19-Ubuntu SMP i686 GNU/Linux

Its Alpha 3 of Ubuntu Karmic Koala Server release.

Report the annonying bug !

How to open CLI to VMware ESXi. How to Clone Virtual Machines.

Written by config on . Posted in Linux

ESXi Commands

You can access the CLI by switching to terminal 1 using Alt-F1.
Now type “unsupported”, This is not echoed so you won’t see anything. If you get it right, you will get a prompt asking for the root pasword.

( This might not work in ESXi 4.0 as VMWare is trying to limit ESXi for their own corporate reasons )

That drops you at a shell prompt. (ash is our shell).
Hint: editor = vi

Now you can you modify /etc/inetd.conf and uncomment the ssh line so that you can ssh into it unless you are planning always being at the console.
Reboot (init 6)

Cloning Virtual machines in ESXi

vmkfs tools -i /vmfs/volumes/datastore/YourVM/YourVM.vmdk /vmfs/volumes/datastore/NewVM/newvm.vmdk
vim-cmd vmsvc/getallvms
vim-cmd vmsvc/power.reset xx

check out these ( with vim-cmd vmsvc/command ):

power.off
power.on
power.reboot
power.reset
power.shutdown
power.suspend

esxtop = is your top tool

How to find biggest files in directory.

Written by config on . Posted in Linux, Mac OSX

Something you probably have to do now and then is to find the biggest files in directory to delete / destroy / eliminate or explode the damn space wasters. Here is one of the ways to find it:

ls -lSrh

The “r” switch will cause all the large files to be listed at the end and the “h”switch will make your life easier and will show you human readable data (MB etc..). You could also search for the biggest AVIs for example:

ls -lSrh *.avi

You can also check what are the largest directories with this one:

du -kx | egrep -v "\./.+/" | sort -n