• What is EPCKPT?
• How to download
• Mirror Sites
• Features and Known Bugs
• License Agreement
• The Author
• Installation and Documentation
• Known People and Projects using EPCKPT
• Links

EPCKPT is a checkpoint/restart utility built into the Linux kernel. Checkpointing is the ability to save an image of the state of a process (or group of processes) at a certain point during its lifetime. Checkpoints are important to a wide range of applications. The most common uses for checkpointing are:

• Fault-tolerance
• Applications trace/Debugging
• Rollback/Animated playback
• Process migration

EPCKPT is part of the Nomad distributed operating system developed at the COPPE Systems Engineering Department of the Federal University of Rio de Janeiro (UFRJ) in Brazil.

Epckpt is under development. Currently it is restricted to the Intel x86 platform running Linux. The available Linux versions are:

Linux 2.4 series

• Epckpt BETA for Linux 2.4.2 -- BETA version. See below. (Release date: 15/Mar/2001)

• Epckpt for Linux 2.2.1

• Epckpt for Linux 2.0.29
• Epckpt for Linux 2.0.33
• Epckpt for Linux 2.0.36 (thanks to Werner G. Krebs -- werner.krebs@yale.edu)

Before downloading, please read the License Agreement below.

Mirror Sites
No known mirror sites anymore.

Epckpt is capable of checkpointing:

• Processes' memory, stack and registers
• Open or mmap'ed files
• Current directory (finally implemented)
• Open pipes
• System V IPC
  • Semaphores
  • Shared Memory
• Fork Parallel Applications
• Dynamic Load Libraries

Epckpt's main features are:

• Save and continue or save and kill policies.
• Save whole memory area or data pages only (the ones that cannot be retrieved from the executable file)

• Sockets
• System V IPC Messages Queues (as easy as pipes, but not implemented yet)
• Timers (sleeping processes will be awakened)

• Everything on the "Not-capable-list" except sockets!

• Some combinations of opening files and changing current directory won't work. It's safer to use the full path name when opening files, if possible, or not changing the current directory once a file has been opened.

• No more restart syscall. Now EPCKPT is an executable format like ELF.
• Pipes were made generic. Now all combinations of pipes work fine, not only pipes from the parent process to its children processes
• Better synchonization. Avoids some rare-cases (but harmful) race conditions
• Saves current directories (easy, but only added now)

EPCKPT is being tested. It is provided as-is and neither the author nor his institution will be liable for anything that might happen after its installation.
EPCKPT is Copyrighted by Eduardo Pinheiro and is distributed under the GNU Copyleft license version 2 or later.
Please send modifications, bug reports and comments to edpin@cs.rutgers.edu.

Eduardo Pinheiro (edpin@cs.rutgers.edu)- Full-time PhD. student.

So far, there is not much documentation available. Since EPCKPT is only part of a much more complex project (the Nomad distributed operating system), there will not be a huge effort to document it thoroughly. But, some time ago, I wrote a draft of an internal report about EPCKPT. It might help a little bit.

• Postcript Version (40 kbytes)
• HTML Version (thanks to Adam Feuer)

For installation please download the patches and read the README file. For further information contact the author.

Known People and Projects using EPCKPT

These are currently known people and their projects using EPCKPT as a tool. If you have your own project that uses EPCKPT and wishes to be listed here let me know. Conversely, if you or your project are listed here and it shouldn't or you don't want it to be here, also let me know.

• Kernel Hot Swap Project at Source Forge(Coling Slater)
• GNU Queue Project (Werner G. Krebs)
• Beowulf Migration Project (Jeffrey Moyer)
• Migration Project ( Adam Feuer)

• Checkpointing.org -- Numerous resources and links to checkpointing-related stuff.
• People talking about EPCKPT -- EPCKPT has caused a humongous amount of discussion in news groups and other places.

visitors since 18/May/1998