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 http://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 http://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.xen-bugtool
1xen-bugtool
2===========
3
4The xen-bugtool command line application will collate the Xen dmesg output,
5details of the hardware configuration of your machine, information about the
6build of Xen that you are using, plus, if you allow it, various logs.
7
8The information collated can either be posted to a Xen Bugzilla bug (this bug
9must already exist in the system, and you must be a registered user there), or
10it can be saved as a .tar.bz2 for sending or archiving.
11
12The collated logs may contain private information, and if you are at all
13worried about that, you should not use this tool, or you should explicitly
14exclude those logs from the archive.
15
16xen-bugtool is wholly interactive, so simply run it, and answer the questions.
17