Install One Ubuntu Version from ISO of Another?

[klausner]

If I'm booted into Ubuntu version X from /dev/sda, and have an ISO image of version Y mounted (using Gmount-iso), or have a CD of Y, can I install Y to /dev/sdb without booting Y?

[klausner]

Bump.

[oldfred]

You can use grub2 to loop mount an ISO and then run it. While the links are for USB it can be done from another partition. You just have to be careful of what partitions are mounted.

MultiBoot USB with Grub2 (boot directly from iso files)
http://www.panticz.de/MultiBootUSB
HOWTO: Booting LiveCD ISOs from USB flash drive with Grub2
http://ubuntu-ky.ubuntuforums.org/sh....php?t=1288604
http://ubuntuforums.org/showthread.php?t=1451184
http://members.iinet.net/~herman546/...l#cli_loopback
http://ubuntuforums.org/showthread.php?t=1224417

[gordintoronto]

Yes, you can run USB Administration/Startup Disk Creator, point it at an ISO on your system, and create that version of Linux. You don't have to mount the ISO, maybe you should not mount the ISO.

I downloaded the Lubuntu ISO and did exactly this, to get a persistent flash drive which boots Lubuntu.

[gordintoronto]

You can use grub2 to loop mount an ISO and then run it. While the links are for USB it can be done from another partition. You just have to be careful of what partitions are mounted.

MultiBoot USB with Grub2 (boot directly from iso files)
http://www.panticz.de/MultiBootUSB
HOWTO: Booting LiveCD ISOs from USB flash drive with Grub2
http://ubuntu-ky.ubuntuforums.org/sh....php?t=1288604
http://ubuntuforums.org/showthread.php?t=1451184
http://members.iinet.net/~herman546/...l#cli_loopback
http://ubuntuforums.org/showthread.php?t=1224417

This is much more complicated than the simple solution, USB Startup Disk Creator.

[oldfred]

Yes it is more complicated the first time.

But I have 4 copies of Ubuntu, gparted, system rescue and one or two more, all one one USB. I can update by just copying the ISO over and editing grub.