chroot to oldlinux to run legacy app, with X

[Gilboa Davara]

On Sun, 2006-09-24 at 14:16 +0000, Jack Byers wrote:
> 
> Jack Byers     byersj at hotmail.com
> 
> How to chroot to oldlinux to run legacy app, with X
> 
> Assume you have a legacy app available in an older linux,
> which is dual booted with your new main linux.
> 
> in my case mainlinux is fc5,
> oldlinux is rh8, mounted under /corni when booted in fc5
> 
> Since this is dual boot, i can of course
> reboot into the oldlinux to run legacyapp
> but that is awkward and inconvient
> 
> Instead chrooting into the oldlinux
> allows you to run legacyapp while still booted up in fc5
> 
> What took me a long time, much googling, to find out
> was how to also run X in that chroot
> 
> first do folowing two commands  from your mainlinux
> [root at bootp byers]# mount --bind /tmp /corni/tmp
> [root at bootp byers]# xhost local:localhost
> 
> I do all my work from xterms,
> which is probably why that xhost cmd is needed
> 
> I tried various ways to use startx from a console in the chroot
> but never succeeded.
> 
> The above 2 cmds are all that is needed for X to be avail
> in the chroot
> 
> then do the chroot:
> 
> # /usr/sbin/chroot /corni
> # cd home
> # cd byers
> #  su byers
> $  /pathtolegacyapp
> 
> works just as it did when rh8 was my mainlinux
> 
> The oldlinux needn't even be bootable.
> 
> I think this will work chrooting from any linux to any other linux,
> _except_
> I have been told trouble will occur
> if trying to chroot from a 64bit linux to a 32bit linux
> I  dont yet have 64bit linux but will soon
> Any advice when trying chroot 64bit ->32 bit?
> 
> Jack
> 
> 

Don't forget the .Xauthority cookie.
$ cp  /home/<your home>/.Xauthority   /mnt/FC4/home/<your chroot home>

Gilboa