README.colo
1COLO FT/HA (COarse-grain LOck-stepping Virtual Machines for Non-stop Service)
2project is a high availability solution. Both primary VM (PVM) and secondary VM
3(SVM) run in parallel. They receive the same request from client, and generate
4response in parallel too. If the response packets from PVM and SVM are
5identical, they are released immediately. Otherwise, a VM checkpoint (on demand)
6is conducted.
7
8See the website at https://wiki.xen.org/wiki/COLO_-_Coarse_Grain_Lock_Stepping
9for details.
10
README.remus
1Remus provides fault tolerance for virtual machines by sending continuous
2checkpoints to a backup, which will activate if the target VM fails.
3
4See the website at https://wiki.xen.org/wiki/Remus for details.
5
6Using Remus with libxl on Xen 4.5 and higher:
7 To enable network buffering, you need libnl 3.2.8
8 or higher along with the development headers and command line utilities.
9 If your distro does not have the appropriate libnl3 version, you can find
10 the latest source tarball of libnl3 at http://www.carisma.slowglass.com/~tgr/libnl/
11
12Disk replication:
13 VMs protected by Remus need to use DRBD based disk backends. Specifically, you
14 need a compile and install a custom version of DRBD, that is available publicly
15 at https://github.com/rshriram/remus-drbd
16 This code is based on DRBD 8.3.11 and uses a new replication protocol (named
17 protocol D) for asynchronous disk checkpoint replication. A protected VM's DRBD
18 disks on the primary and backup hosts need to be configured to use protocol D
19 as the replication protocol. An example resource configuration file can be found
20 in the aforementioned github repository.
21
README.source
1Sphinx documentation:
2
3All source rendered by Sphinx is licensed under CC-BY-4.0.
4
5You are free to:
6 Share:
7 Copy and redistribute the material in any medium or format.
8 Adapt:
9 Remix, transform, and build upon the material for any purpose, even
10 commercially.
11
12Under the following terms:
13 Attribution:
14 You must give appropriate credit, provide a link to the license, and
15 indicate if changes were made. You may do so in any reasonable manner, but
16 not in any way that suggests the licensor endorses you or your use.
17 No additional restrictions:
18 You may not apply legal terms or technological measures that legally
19 restrict others from doing anything the license permits.
20
21See https://creativecommons.org/licenses/by/4.0/ for full details.
22
23This includes:
24 * All ReStructured Text files: docs/*/*.rst
25 * The Sphinx configuration file: docs/conf.py
26 * Content in Sphinx-exclusive subdirs: docs/*-guide/*
27
28
29Other documentation:
30
31There are a variety of text documents in various formats. These, given no
32explicit license guidance, fall under Xen's default GPL-2.0 license.
33