Writing my post from Open solaris . This is a great experience , so thought to share with you , so may help some of you. I have once installed the Sun Solaris , not the Open Solaris of sun . And it was really a tedious job . So I was aware of the consequences . But thought of trying the Open Solaris , as I love to use it after trying the Live CD. Though I have got the CD some days before , not able to try it. Current OS and status 1 ) Installed Ubuntu 8.10 , having lots of additional softwares installed and lots of valuable data’s :–) . 2 ) Don’t want to miss any , like the previous case. Started Installation around 12:30 noon . It takes some time to install the OS. I came after my Lunch and by the time it has finished the installation . Restarted the system. The grub loads ………… OOP’s really fucking , the Ubuntu is not there , it has gone . The boot loader has gone . Anyway thought of reinstalling the grub . I have installed from Fedora the boot loader , but not from Ubuntu , so thought of editing the grub file for the sun solaris. But I need to know the real path to the Ubuntu kernel . Booted from Ubuntu Live CD , searched google to find from where I will get the complete path ? Yes, found a solution for it , ( https://sourceforge.net/projects/bootinfoscript/ ). Downloaded and tried , got the result. Saved in gmail :–) . Restarted the system , logged to Open solairs . Looked to edit grub . Searched a lot , got some information from blog of sun. He is a worker at Sun . ( http://blogs.sun.com/agraj/entry/editing_grub_bootloader ) . But I was not able to find the /etc/grub.conf nor the /boot/grub/menu.lst ( Skipping some of the steps I have tried to edit grub from command prompt ) . And finally I was forced to login to Live CD , and tried to do like the steps in http://ubuntuforums.org/archive/index.php/t-24113.html the post . But what I missed was Open Solaris loader and time and the updated kernel of Ubuntu . What it does was installed the Ubuntu OS again .So never go in these ways , I will shortly tell the other one. Why I told never go in this way is because it will remove some of the files of our updated kernel , though it can backup our files. And finally I edited the /boot/grub/menu.lst of the Ubuntu distro and added the code title Open Solaris root (hd0,0) makeactive chainloader +1 The pretty simple way ( I was not able to try this , but found the menu.lst of Open Solaris ) : 1 ) Install Solaris 2 ) Boot with Live CD , install the boot info script and run it ( https://sourceforge.net/projects/bootinfoscript/ ) . Save the RESULTS.txt may be in you mail or thumb . 3 ) Restart to login to Open Solaris . Edit the menu.lst , ( its not located at /etc/grub.conf nor at /boot/grub/ ) . The menu.lst has moved to /rpool/boot/grub/ folder . So what you need to do is just edit the /rpool/boot/grub/menu.lst . You must be root to edit this file ( Use su or sudo ). Copy and paste the lines you have got from the RESULTS.txt which is produced by the boot info script . Some thing starting like ## ## End Default Options ## and ending with ### END DEBIAN AUTOMAGIC KERNELS LIST . You can have a search if you are using gedit . Now restart your system . It will works . Defnitely it will work . Have fun with solaris too . Spend my whole day for this experiment :–( . But learned a lot of new things , so I gained :–) Thanks guys , let me have some sleep its 1:05 Am . Want to cast my vote and leave to work tomorrow morning . Bye have a great day .