chroot, bind mount without root privilege/setup

proot -r /media/user/ubuntu12.10/ cat /etc/motd
PRoot is a user-space implementation of chroot, mount --bind, and binfmt_misc. This means that users don't need any privileges or setup to do things like using an arbitrary directory as the new root filesystem, making files accessible somewhere else in the filesystem hierarchy, or executing programs built for another CPU architecture transparently through QEMU user-mode. Also, developers can use PRoot as a generic Linux process instrumentation engine thanks to its extension mechanism, see CARE for an example. Technically PRoot relies on ptrace, an unprivileged system-call available in every Linux kernel. https://github.com/cedric-vincent/PRoot
Sample Output
$proot -r /media/user/ubuntu12.10/  cat /etc/motd

Welcome to Ubuntu 12.10 (GNU/Linux 3.5.0-17-generic i686)

 * Documentation:  https://help.ubuntu.com/

2
By: totti
2014-01-21 07:50:22

These Might Interest You

  • The command is useful when, e.g., booting an existing system with a rescue or installation CD where you need to chroot into the hard-disk and be able to do stuff which accesses kernel info (e.g. when installing Ubuntu desktop with LVM2 you need to mount and chroot the hard disk from a shell window in order to install packages and run initramfs inside chroot). The command assumes that /mnt/xxx is where the chroot'ed environment's root file system on the hard disk is mounted.


    3
    for i in sys dev proc; do sudo mount --bind /$i /mnt/xxx/$i; done
    amosshapira · 2009-04-20 16:52:14 1
  • Like symlinked directories, you can mount a directory at a different location. For example mounting a directory from one location in to the http root without having to make your program follow symlinks or change permissions when reading.


    4
    mount --bind /old/directory/path /new/directory/path
    dryicerx · 2009-04-19 01:44:59 1
  • Usage: VBoxBlockBoot [Virtual_Machine] [Block_device] Eg: VBoxBlockBoot WinXP /dev/sdc In another words vm=usb; usb=sdc;sudo umount /dev/$usb* ; sudo chmod 777 /dev/$usb ; VBoxManage storageattach $vm --medium ~/raw-HD-4-VB/$usb.vmdk --type hdd --storagectl "IDE Controller" --device 0 --port 0 ; VBoxManage startvm $vm Where vm --> Name of the virtual machine to start usb --> Block device to use. (/dev/sdc) This can used after setup up a boot loader on to my USB pen drive or HDD (After creating Live USB). Here root privilege is needed but not granted to Virtual Box. Thus we can access all our VM.( If we run VBox as root we can't access our VMs). Root privilege is used to - Unmount the storage device - Chmod to full access (777) Requirements:- 1. Device information file (rawvmdk file) created by the following command. Need to run only once. Not bad to run many. VBoxCreateRawDisk() { VBoxManage internalcommands createrawvmdk -filename ~/.rawHD4VB_`basename "$1"`.vmdk -rawdisk "$1"; } 2. Root privilege to umount & chmod 3. Real storage medium (ie /dev/*) (Non-virtual such as USB HD, pen drive, a partition) 4. A virtual m/c already available (here "usb") vm=usb; usb=sdc;sudo umount /dev/$usb* ; sudo chmod 777 /dev/$usb ; VBoxManage storageattach $vm --medium ~/raw-HD-4-VB/$usb.vmdk --type hdd --storagectl "IDE Controller" --device 0 --port 0 ; VBoxManage startvm $vm VBoxBlockBoot() { sudo umount "$2"*; sudo chmod 777 "$2"; VBoxManage storageattach "$1" --medium ~/.rawHD4VB_`basename "$2"`.vmdk --type hdd --storagectl "IDE Controller" --device 0 --port 0 ; VBoxManage startvm "$1"; } Show Sample Output


    0
    VBoxBlockBoot() { sudo umount "$2"*; sudo chmod 777 "$2"; VBoxManage storageattach "$1" --medium ~/.rawHD4VB_`basename "$2"`.vmdk --type hdd --storagectl "IDE Controller" --device 0 --port 0 ; VBoxManage startvm "$1";}
    totti · 2011-07-29 13:04:19 0

  • 3
    !w sudo tee %
    chemila · 2011-11-10 06:15:40 0

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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