Hello guys I want to install open mandriva on a USB. My plan was to boot it in live mode and then install it on another flash drive to have it installed and use it as a complete OS.

I want to prevent any type of changes to my internal hard drives. So I think to boot up the flash drive, unmount the 2 internal hard drives and then install the system on the mounted flashdrive. My question is do I have to unmount the disks in the live environment and I'm ok or I have to fisically remove the hard drives from the computer? Also if I unmount the hard drives in the open mandriva live environment are they unmounted even when I boot up my main normal OS (that is installed on the 2 hard drives) or the os will automatically mount them as usual ?

I always hate live distros that automatically mount internal drives!

You can boot up into live mode, insert your 2nd pendrive, open a terminal & type
that will show you what your 2nd pendrive has been designated, (probably /dev/sdd in your case with two internal HDDs), now you just install to that drive.

If you want to, you can of course, unmount your internal drives as well, best safe than sorry, but you should be offered all available drives to choose which to install to anyway.

Thank you my friend. So I don't have to fisically remove them from the case just unmount them and I'm ok ?
Thank you very much again for the reply.

If the drives are physically connected, there is still a (marginal) possibility that they can be written to. You could disconnect them logically with
where X is the drive letter (the precise file path may be different on Mandriva)

Second question: Unmounting the drives in the live OS has no effect on the disk-based OS.

Is this command echo > /sys/class/block/sdX/device/delete dangerous maybe when I boot into the disk os the drives will be logically disconnected or this command only affects the live distro? And also where you wrote device you mean dev/sda, /dev/sdb ecc...

The command tells the kernel to "forget" the disk. When you reboot, a new kernel is created in RAM and discovers all hardware anew. The new kernel is not affected.

Yes, I meant sda, sdb etc. Pick the correct ones, otherwise the Live OS will act funny.

Thank you very much supportive people like you are the ones that make linux great.

Bro I wrote echo > /sys/class/block/sdX//dev/sdb/delete and it says me "There is no such file or directory"

ok now I found the correct syntax but the the terminal says permission denied even as root.

/sys/class/block/sdb/device/delete (without dev and sdX, but with device). As I said, might be different in your distro.

I found out the syntax but It says permission denied even executing the command as root.