chroot not working: "cannot run command `/bin/bash': No such file or directory"

[Geraba]

I'm trying to change the root directory to /tmp/somedir using chroot, but even using sudo or su-ing to root I get the message:

cannot run command `/bin/bash': No such file or directory

I tried copying /bin/bash to /tmp/somedir/, but the same error occurs. What's wrong with my chroot?

[yabbadabbadont]

Please post the exact command you run when trying to chroot.

[Geraba]

sudo chroot /tmp/somedir

or

sudo chroot /tmp/somedir bash

[sisco311]

How did you create the chroot environment?

What's the content of /tmp/somedir?

ls /tmp/somedir

[Geraba]

I had just created it with "mkdir /tmp/somedir"

Since I copied bash to it, ls /tmp/somedir gives:

bin

and inside it is just bash.

[soltanis]

From the manpage:

NAME
       chroot - run command or interactive shell with special root directory

SYNOPSIS
       chroot NEWROOT [COMMAND [ARG]...]
       chroot OPTION

Without any command, as you invoked it, chroot attempts to run the shell (/bin/sh) but if that doesn't exist in the target directory, then it won't work out.

If you want to run a specific command in a chroot'ed jail, you should just invoke the command directly instead of trying to meticulously set up an environment within an environment -- much easier that way.

[sisco311]

I had just created it with "mkdir /tmp/somedir"

Since I copied bash to it, ls /tmp/somedir gives:

bin

and inside it is just bash.

The chroot directory must be populated with a minimum set of files.

You can use debootstrap to create a minimal, Ubuntu or Debian, chroot environment: /community/DebootstrapChroot.

[Geraba]

But since I copied bash there, shouldn't it at least run and then give an error about the lack of files?

[OK23]

Hello,
thread is dead for more than 10 months, but maybe this reply will save someone precioussss time...

For chrooting few things must be done:

1. creation of directory for chroot environment - e.g. /home/chroot
   
   
2. creation subdirectories proc, dev and lib inside above chroot directory:
   

   mkdir /home/chroot/{dev,proc,lib}

3. binding /dev/ and /proc/ directories to this chroot directory:
   

   mount --bind /dev/ /home/chroot/dev/
   mount --bind /proc/ /home/chroot/proc/

4. copying/link files which will be used in chrooted environment into /home/chroot/ into proper directory - e.g. /bin/bash should be placed in /home/chroot/bin/bash
   
   
5. finding and copying/link library files needed for above files (e.g. /bin/bash) into proper directories, must be used command:
   

   ldd /bin/bash

And after all of this you can try to run chroot environment. I hope that I haven't miss anything important. In fact you should try to google for setting chroot

At last, but not least: message cannot run command `/bin/bash': No such file or directory" is not complete and can be misleading. It should be more complete for example like this: cannot run command `/bin/bash': No such file, directory or library files for this command".
Without 2 last steps of creating chroot list, /bin/bash in chrooted environment won't run even if bash would be placed in /home/chroot/bin/ directory (without proper libraries).

[sisco311]

Thread Closed.