What does a chroot do to a Linux system?
According to Wikipedia, a chroot: changes the apparent root directory for the current running process and its children. A program that is run in such a modified environment cannot name (and therefore normally cannot access) files outside the designated directory tree. As a Linux user, there are 2 types of chroot you may encounter.
How to chroot into a broken Linux install?
Enough utilities to allow you to build further C packages. You’d run the command ’emerge system’ and it would go off and build gcc, glibc, coreutils etc. Once these were built you’d then rebuild glibc, and gcc with your newly compiled, architecture specific, compiler and c library.
Can a chroot run in a modified environment?
A program that is run in such a modified environment cannot name (and therefore normally cannot access) files outside the designated directory tree. As a Linux user, there are 2 types of chroot you may encounter. What I call a “standard” chroot (what this doc page covers), then there is also a “chroot jail”.
Do you need to mount proc and Dev on a chroot?
If you have a separate boot partition mount that too. Now in order to have a functional chroot, we need the proc, dev and sys subsystems to be mounted onto the chroot. This is the tricky bit. In the case of the sys and dev dirs, we need to reference the exact same mountpoints as the host so we use the -o bind option.
How to update the Grub config in chroot Linux?
The only way to look at the grub config is to copy the root filesystem image, mount it on a functional system, make changes to the grub config file and run update-grub on the chrooted environment for the grub changes to take effect. Later write the updated image on the failed system and hopefully it boots up.
How to chroot into a broken system via Turnkey Linux?
The first thing to do is to ensure that the filesystem of the broken system is accessible from the working system. In the case of a bare metal install or a VM, the easiest way to do this is often to just boot from a Live CD/USB/ISO. As a general rule, it’s usually best to use the same OS as what the broken system is.