Good Day:

What is the code to change the boot flag from sdb1 to sdb2 in Terminal (not using gparted)? Thank you for your help in advance.

You can use "parted":

Solved. Thank you.

The following text was an answer to a question in another forum. I wanted to share the experience here so maybe i could be helpful to others too. I got the answer to my original question here so thank you.

I found the answer in a different forum. What i was looking for was "parted /dev/sdb set 2 boot on"

What i m trying to do is actually is very interesting and can help others if they r interested. I want to have Ubuntu Prsistent Live and Backtract Live(not Persistent) on the same usb drive.

I have tried so many ways but it wouldnt work. But today here is the solution that i came up with and it seems like it is working. What i did was i format the usb drive into two partitions fat32. By using UNetBootin i installed ubuntu in one partition and backtrack in the other one. But i couldnt choose which os to start at unetbootin start up. Since i installed backtrack after ubuntu, unetbootin would start backtrack at start up. In the usb there is ununtu and backtrack but i had to change the boot flag in order to change unetbootin's start up os. Backtrack doesnt have gparted. Thats why i needed to figure out how to change the boot flag throught the terminal. Now what i do is i log into lets say ubuntu lets say in sdb1 through unetbootin on the usb then if i want to change the os to backtrack i change the boot flag to sdb2 in ubuntu before restart then when i restart and i chose to boot from usb, unetbootin logs in and opens the backtrack options. Then i login to backtrack. If i wantt o change to ubuntu then in backtrack i change the boot flag in terminal again to ubuntu then reboot start from usb unetbootin loads ubuntu ))

I had written here before thats what i wanted to do so it seems like i found the solution. It would be much better if i could work in grub meaning that i start the computer from the usb and at grub choose either ubuntu persistent or backtrack live. That would be the best but i couldnt do it that way. If you have a better way of doing it let me know. But for now thats what i ll be suggesting people.

The main reason why i wanted to have the ubuntu persistent is because i dont want to change the settings everytime and install necessary packages everytime. But in Bactrack i dont want to mess up the settings so i want a clean default backtrack everytime i log in. Thats why. Makes sense?