Installation

What CRtools is

CRtools is an utility to checkpoint/restore process tree. Unlike checkpoint/restore implemented completely in kernel space, it tries to achieve the same target operating in user space. Since the tools and overall concept are still under heavy development stage there are some known limitations applied

1. Only pure x86-64 environment is supported, no IA32 emulation allowed.
2. There is no way to use cgroups freezer facility yet.
3. No IPC checkpoint/restore supported, and network is under hard development stage.

Download crtools

The crtools utility itself is hosted at git.criu.org. Clone this repo to test new functionality. Anything but master branch are development ones, don't refer on them.

Also crtools requires some additional patches to be applied on the linux kernel.

So clone linux-2.6-crtools.git, checkout crtools-3.5-rc4-1 branch and compile the kernel.

Configure the linux kernel

Make sure you have the following options turned on

• General setup -> Checkpoint/restore support (CONFIG_CHECKPOINT_RESTORE)
• Networking support -> Networking options -> Unix domain sockets -> UNIX: socket monitoring interface (CONFIG_UNIX_DIAG)
• Networking support -> Networking options -> TCP/IP networking -> INET: socket monitoring interface (CONFIG_INET_DIAG)
• General setup -> open by fhandle syscalls
• File systems -> Inotify support for userspace
• General setup -> Enable eventfd() system call
• General setup -> Enable eventpoll support

Note you might have to enable

• General setup -> Configure standard kernel features (expert users) (CONFIG_EXPERT)

option, which depends on

• General setup -> Embedded system (CONFIG_EMBEDDED)

(welcome to Kconfig reverse chains hell).

Using CR tools

Please see running CR tools article.

CR tools mailing list

If you're interested in CR tools development don't hesitate to subscribe to the CRtools mailing list which can be found here [1].