X-Git-Url: https://code.grnet.gr/git/ganeti-local/blobdiff_plain/e2078d280d462ce583288ecd6279e22b198cb652..99c7cd5be025e86745aa46003ca0962609e0b4e2:/doc/glossary.rst diff --git a/doc/glossary.rst b/doc/glossary.rst index 6bbf0a9..f1c255e 100644 --- a/doc/glossary.rst +++ b/doc/glossary.rst @@ -5,26 +5,86 @@ Glossary .. if you add new entries, keep the alphabetical sorting! .. glossary:: + :sorted: + + ballooning + A term describing runtime, dynamic changes to an instance's memory, + without having to reboot the instance. Depending on the hypervisor + and configuration, the changes need to be initiated manually, or + they can be automatically initiated by the hypervisor based on the + node and instances memory usage. + + BE parameter + BE stands for *backend*. BE parameters are hypervisor-independent + instance parameters such as the amount of RAM/virtual CPUs it has + been allocated. + + DRBD + A block device driver that can be used to build RAID1 across the + network or even shared storage, while using only locally-attached + storage. + + HV parameter + HV stands for *hypervisor*. HV parameters are the ones that describe + the virtualization-specific aspects of the instance; for example, + what kernel to use to boot the instance (if any), or what emulation + model to use for the emulated hard drives. HVM - Hardware virtualization mode, where the virtual machine is - oblivious to the fact that's being virtualized and all the - hardware is emulated. + Hardware virtualization mode, where the virtual machine is oblivious + to the fact that's being virtualized and all the hardware is + emulated. LogicalUnit - The code associated with an OpCode, e.g. the code that implements - the startup of an instance. + The code associated with an :term:`OpCode`, e.g. the code that + implements the startup of an instance. + + LUXI + Local UniX Interface. The IPC method over :manpage:`unix(7)` + sockets used between the CLI tools/RAPI daemon and the master + daemon. + + OOB + *Out of Band*. This term describes methods of accessing a machine + (or parts of a machine) not via the usual network connection. For + example, accessing a remote server via a physical serial console or + via a virtual one IPMI counts as out of band access. OpCode - A data structure encapsulating a basic cluster operation; for example, - start instance, add instance, etc. + A data structure encapsulating a basic cluster operation; for + example, start instance, add instance, etc. PVM - Para-virtualization mode, where the virtual machine knows it's being - virtualized and as such there is no need for hardware emulation. + (Xen) Para-virtualization mode, where the virtual machine knows it's + being virtualized and as such there is no need for hardware + emulation or virtualization. + + SoR + *State of Record*. Refers to values/properties that come from an + authoritative configuration source. For example, the maximum VCPU + over-subscription ratio is a *SoR* value, but the current + over-subscription ration (based on how many instances live on the + node) is a :term:`SoW` value. + + SoW + *State of the World*. Refers to values that describe directly the + world, as opposed to values that come from the + configuration. Contrast with :term:`SoR`. + + tmem + Xen Transcendent Memory + (http://en.wikipedia.org/wiki/Transcendent_memory). It is a + mechanism used by Xen to provide memory over-subscription. watcher - ``ganeti-watcher`` is a tool that should be run regularly from cron - and takes care of restarting failed instances, restarting secondary - DRBD devices, etc. For more details, see the man page + :command:`ganeti-watcher` is a tool that should be run regularly + from cron and takes care of restarting failed instances, restarting + secondary DRBD devices, etc. For more details, see the man page :manpage:`ganeti-watcher(8)`. + + +.. vim: set textwidth=72 : +.. Local Variables: +.. mode: rst +.. fill-column: 72 +.. End: