Provided by: ganeti2_2.4.5-1_all bug

Name

       ganeti - cluster-based virtualization management

Synopsis


             # gnt-cluster init cluster1.example.com
             # gnt-node add node2.example.com
             # gnt-instance add -n node2.example.com \
             > -o debootstrap --disk 0:size=30g \
             > -t plain instance1.example.com

DESCRIPTION

       The  Ganeti  software manages physical nodes and virtual instances of a cluster based on a
       virtualization software. The current version (2.3) supports Xen 3.x and KVM (72 or  above)
       as hypervisors, and LXC as an experimental hypervisor.

Quick start

       First  you  must install the software on all the cluster nodes, either from sources or (if
       available) from a package. The next step is to create the initial  cluster  configuration,
       using gnt-cluster init.

       Then you can add other nodes, or start creating instances.

Cluster architecture

       In  Ganeti  2.0, the architecture of the cluster is a little more complicated than in 1.2.
       The cluster is coordinated by a master daemon (ganeti-masterd(8)), running on  the  master
       node.   Each  node  runs  (as  before)  a  node daemon, and the master has the RAPI daemon
       running too.

   Node roles
       Each node can be in one of the following states:

       master Only one node per cluster can be in this role, and this node is the one holding the
              authoritative  copy  of  the  cluster  configuration  and the one that can actually
              execute commands on the cluster and modify the  cluster  state.  See  more  details
              under Cluster configuration.

       master_candidate
              The  node receives the full cluster configuration (configuration file and jobs) and
              can become a master via the gnt-cluster master-failover command. Nodes that are not
              in this state cannot transition into the master role due to missing state.

       regular
              This the normal state of a node.

       drained
              Nodes  in  this  state  are  functioning normally but cannot receive new instances,
              because the intention is to set them to offline or remove them from the cluster.

       offline
              These nodes are still recorded in the Ganeti  configuration,  but  except  for  the
              master  daemon  startup  voting  procedure,  they are not actually contacted by the
              master. This state was added in order to allow  broken  machines  (that  are  being
              repaired) to remain in the cluster but without creating problems.

   Node flags
       Nodes have two flags which govern which roles they can take:

       master_capable
              The  node can become a master candidate, and furthermore the master node. When this
              flag is disabled, the node cannot become  a  candidate;  this  can  be  useful  for
              special networking cases, or less reliable hardware.

       vm_capable
              The  node  can  host  instances.  When  enabled  (the default state), the node will
              participate in instance allocation, capacity calculation, etc. When  disabled,  the
              node will be skipped in many cluster checks and operations.

   Node Parameters
       These parameters are node specific and can be preseeded on node-group and cluster level.

       Currently we support the following node parameters:

       oob_program
              Path  to  an  executable  used as the out-of-band helper as described in the Ganeti
              Node OOB Management Framework (design-oob.rst) design document.

   Cluster configuration
       The master node keeps and is responsible for the cluster configuration. On the filesystem,
       this is stored under the /var/ganeti/lib directory, and if the master daemon is stopped it
       can be backed up normally.

       The master daemon will replicate the configuration database called config.data and the job
       files  to  all  the  nodes in the master candidate role. It will also distribute a copy of
       some configuration values via the ssconf files, which are stored in the same directory and
       start with a ssconf_ prefix, to all nodes.

   Jobs
       All cluster modification are done via jobs. A job consists of one or more opcodes, and the
       list of opcodes is processed serially. If an opcode fails, the entire job  is  failed  and
       later opcodes are no longer processed. A job can be in one of the following states:

       queued The job has been submitted but not yet processed by the master daemon.

       waiting
              The job is waiting for for locks before the first of its opcodes.

       canceling
              The  job is waiting for locks, but is has been marked for cancellation. It will not
              transition to running, but to canceled.

       running
              The job is currently being executed.

       canceled
              The job has been canceled before starting execution.

       success
              The job has finished successfully.

       error  The job has failed during runtime, or the master daemon has been stopped during the
              job execution.

Common command line features

   Options
       Many Ganeti commands provide the following options. The availability for a certain command
       can be checked by calling the command using the --help option.

       gnt-... command [--dry-run] [--priority {low | normal | high}]

       The --dry-run option can be used to check whether an operation would succeed.

       The option --priority sets the priority for opcodes submitted by the command.

Field formatting

       Multiple ganeti commands use the same framework for tabular  listing  of  resources  (e.g.
       gnt-instance  list,  gnt-node  list,  gnt-group  list,  gnt-debug  locks, etc.). For these
       commands, special states are denoted via a special symbol (in terse mode) or a string  (in
       verbose mode):

       *, (offline)
              The  node  in  question  is marked offline, and thus it cannot be queried for data.
              This result is persistent until the node is de-offlined.

       ?, (nodata)
              Ganeti expected to receive an answer from this entity, but  the  cluster  RPC  call
              failed  and/or  we  didn't  receive  a  valid  answer;  usually more information is
              available in the node daemon log (if the node is alive) or the master  daemon  log.
              This result is transient, and re-running command might return a different result.

       -, (unavail)
              The  respective  field  doesn't  make  sense for this entity; e.g.  querying a down
              instance for its current memory 'live' usage, or querying a non-vm_capable node for
              disk/memory  data. This result is persistent, and until the entity state is changed
              via ganeti commands, the result won't change.

       ??, (unknown)
              This field is not known (note that this is different from  entity  being  unknown).
              Either you have mis-typed the field name, or you are using a field that the running
              Ganeti master daemon doesn't  know.  This  result  is  persistent,  re-running  the
              command won't change it.

   Key-value parameters
       Multiple  options  take  parameters  that  are  of  the  form  key=value,key=value,...  or
       category:key=value,....  Examples are the hypervisor parameters, backend parameters,  etc.
       For  these,  it's  possible  to  use  values  that  contain  commas by escaping with via a
       backslash (which needs two if not single-quoted, due to shell behaviour):

             # gnt-instance modify -H kernel_path=an\\,example instance1
             # gnt-instance modify -H kernel_path='an\,example' instance1

Common daemon functionality

       All Ganeti daemons re-open the log file(s) when sent a SIGHUP signal. logrotate(8) can  be
       used to rotate Ganeti's log files.

REPORTING BUGS

       Report   bugs   to  project  website  (http://code.google.com/p/ganeti/)  or  contact  the
       developers using the Ganeti mailing list (ganeti@googlegroups.com).

SEE ALSO

       Ganeti overview and specifications: ganeti(7) (general  overview),  ganeti-os-interface(7)
       (guest OS definitions).

       Ganeti   commands:   gnt-cluster(8)   (cluster-wide   commands),  gnt-job(8)  (job-related
       commands), gnt-node(8) (node-related commands), gnt-instance(8) (instance commands),  gnt-
       os(8)  (guest  OS  commands),  gnt-group(8) (node group commands), gnt-backup(8) (instance
       import/export commands), gnt-debug(8) (debug commands).

       Ganeti daemons: ganeti-watcher(8) (automatic instance restarter),  ganeti-cleaner(8)  (job
       queue  cleaner), ganeti-noded(8) (node daemon), ganeti-masterd(8) (master daemon), ganeti-
       rapi(8) (remote API daemon).

COPYRIGHT

       Copyright (C) 2006, 2007, 2008, 2009, 2010 Google Inc.  Permission  is  granted  to  copy,
       distribute and/or modify under the terms of the GNU General Public License as published by
       the Free Software Foundation; either version 2 of the License, or  (at  your  option)  any
       later version.

       On  Debian  systems,  the  complete text of the GNU General Public License can be found in
       /usr/share/common-licenses/GPL.