1 gnt-node(8) Ganeti | Version @GANETI_VERSION@
2 =============================================
7 gnt-node - Node administration
12 **gnt-node** {command} [arguments...]
17 The **gnt-node** is used for managing the (physical) nodes in the
26 | **add** [--readd] [-s *secondary\_ip*] [-g *nodegroup*]
27 | [--master-capable=``yes|no``] [--vm-capable=``yes|no``]
28 | [--node-parameters *ndparams*]
31 Adds the given node to the cluster.
33 This command is used to join a new node to the cluster. You will
34 have to provide the password for root of the node to be able to add
35 the node in the cluster. The command needs to be run on the Ganeti
38 Note that the command is potentially destructive, as it will
39 forcibly join the specified host the cluster, not paying attention
40 to its current status (it could be already in a cluster, etc.)
42 The ``-s`` is used in dual-home clusters and specifies the new node's
43 IP in the secondary network. See the discussion in **gnt-cluster**(8)
46 In case you're readding a node after hardware failure, you can use
47 the ``--readd`` parameter. In this case, you don't need to pass the
48 secondary IP again, it will reused from the cluster. Also, the
49 drained and offline flags of the node will be cleared before
52 The ``--force-join`` option is to proceed with adding a node even if it already
53 appears to belong to another cluster. This is used during cluster merging, for
56 The ``-g`` is used to add the new node into a specific node group,
57 specified by UUID or name. If only one node group exists you can
58 skip this option, otherwise it's mandatory.
60 The ``vm_capable``, ``master_capable`` and ``ndparams`` options are
61 described in **ganeti**(7), and are used to set the properties of the
66 # gnt-node add node5.example.com
67 # gnt-node add -s 192.0.2.5 node5.example.com
68 # gnt-node add -g group2 -s 192.0.2.9 node9.group2.example.com
74 **add-tags** [--from *file*] {*nodename*} {*tag*...}
76 Add tags to the given node. If any of the tags contains invalid
77 characters, the entire operation will abort.
79 If the ``--from`` option is given, the list of tags will be
80 extended with the contents of that file (each line becomes a tag).
81 In this case, there is not need to pass tags on the command line
82 (if you do, both sources will be used). A file name of - will be
88 **evacuate** [-f] [--early-release] [--iallocator *NAME* \|
89 --new-secondary *destination\_node*] {*node*...}
91 This command will move all secondary instances away from the given
92 node(s). It works only for instances having a drbd disk template.
94 The new location for the instances can be specified in two ways:
96 - as a single node for all instances, via the ``--new-secondary``
99 - or via the ``--iallocator`` option, giving a script name as
100 parameter, so each instance will be in turn placed on the (per the
104 The ``--early-release`` changes the code so that the old storage on
105 node being evacuated is removed early (before the resync is
106 completed) and the internal Ganeti locks are also released for both
107 the current secondary and the new secondary, thus allowing more
108 parallelism in the cluster operation. This should be used only when
109 recovering from a disk failure on the current secondary (thus the
110 old storage is already broken) or when the storage on the primary
111 node is known to be fine (thus we won't need the old storage for
116 # gnt-node evacuate -I dumb node3.example.com
122 **failover** [-f] [--ignore-consistency] {*node*}
124 This command will fail over all instances having the given node as
125 primary to their secondary nodes. This works only for instances having
126 a drbd disk template.
128 Normally the failover will check the consistency of the disks before
129 failing over the instance. If you are trying to migrate instances off
130 a dead node, this will fail. Use the ``--ignore-consistency`` option
135 # gnt-node failover node1.example.com
143 Show detailed information about the nodes in the cluster. If you
144 don't give any arguments, all nodes will be shows, otherwise the
145 output will be restricted to the given names.
151 | [--no-headers] [--separator=*SEPARATOR*]
152 | [--units=*UNITS*] [-v] [-o *[+]FIELD,...*]
155 Lists the nodes in the cluster.
157 The ``--no-headers`` option will skip the initial header line. The
158 ``--separator`` option takes an argument which denotes what will be
159 used between the output fields. Both these options are to help
162 The units used to display the numeric values in the output varies,
163 depending on the options given. By default, the values will be
164 formatted in the most appropriate unit. If the ``--separator``
165 option is given, then the values are shown in mebibytes to allow
166 parsing by scripts. In both cases, the ``--units`` option can be
167 used to enforce a given output unit.
169 Queries of nodes will be done in parallel with any running jobs. This might
170 give inconsistent results for the free disk/memory.
172 The ``-v`` option activates verbose mode, which changes the display of
173 special field states (see **ganeti(7)**).
175 The ``-o`` option takes a comma-separated list of output fields.
176 The available fields and their meaning are:
183 the number of instances having this node as primary
186 the list of instances having this node as primary, comma separated
189 the number of instances having this node as a secondary node
192 the list of instances having this node as a secondary node, comma
196 the primary ip of this node (used for cluster communication)
199 the secondary ip of this node (used for data replication in dual-ip
200 clusters, see gnt-cluster(8)
203 total disk space in the volume group used for instance disk
207 available disk space in the volume group
210 total memory on the physical node
213 the memory used by the node itself
216 memory available for instance allocations
219 the node bootid value; this is a linux specific feature that
220 assigns a new UUID to the node at each boot and can be use to
221 detect node reboots (by tracking changes in this value)
224 comma-separated list of the node's tags
227 the so called 'serial number' of the node; this is a numeric field
228 that is incremented each time the node is modified, and it can be
229 used to detect modifications
232 the creation time of the node; note that this field contains spaces
233 and as such it's harder to parse
235 if this attribute is not present (e.g. when upgrading from older
236 versions), then "N/A" will be shown instead
239 the last modification time of the node; note that this field
240 contains spaces and as such it's harder to parse
242 if this attribute is not present (e.g. when upgrading from older
243 versions), then "N/A" will be shown instead
246 Show the UUID of the node (generated automatically by Ganeti)
249 the toal number of logical processors
252 the number of NUMA domains on the node, if the hypervisor can
253 export this information
256 the number of physical CPU sockets, if the hypervisor can export
260 whether the node is a master candidate or not
263 whether the node is drained or not; the cluster still communicates
264 with drained nodes but excludes them from allocation operations
267 whether the node is offline or not; if offline, the cluster does
268 not communicate with offline nodes; useful for nodes that are not
269 reachable in order to avoid delays
272 A condensed version of the node flags; this field will output a
273 one-character field, with the following possible values:
275 - *M* for the master node
277 - *C* for a master candidate
279 - *R* for a regular node
281 - *D* for a drained node
283 - *O* for an offline node
286 whether the node can become a master candidate
289 whether the node can host instances
292 the name of the node's group, if known (the query is done without
293 locking, so data consistency is not guaranteed)
296 the UUID of the node's group
299 If the value of the option starts with the character ``+``, the new
300 fields will be added to the default list. This allows to quickly
301 see the default list plus a few other fields, instead of retyping
302 the entire list of fields.
304 Note that some of this fields are known from the configuration of
305 the cluster (e.g. name, pinst, sinst, pip, sip and thus the master
306 does not need to contact the node for this data (making the listing
307 fast if only fields from this set are selected), whereas the other
308 fields are "live" fields and we need to make a query to the cluster
311 Depending on the virtualization type and implementation details,
312 the mtotal, mnode and mfree may have slighly varying meanings. For
313 example, some solutions share the node memory with the pool of
314 memory used for instances (KVM), whereas others have separate
315 memory for the node and for the instances (Xen).
317 If no node names are given, then all nodes are queried. Otherwise,
318 only the given nodes will be listed.
324 **list-fields** [field...]
326 Lists available fields for nodes.
332 **list-tags** {*nodename*}
334 List the tags of the given node.
339 **migrate** [-f] [--non-live] [--migration-mode=live\|non-live]
342 This command will migrate all instances having the given node as
343 primary to their secondary nodes. This works only for instances
344 having a drbd disk template.
346 As for the **gnt-instance migrate** command, the options
347 ``--no-live`` and ``--migration-mode`` can be given to influence
352 # gnt-node migrate node1.example.com
358 | **modify** [-f] [--submit]
359 | [--master-candidate=``yes|no``] [--drained=``yes|no``] [--offline=``yes|no``]
360 | [--master-capable=``yes|no``] [--vm-capable=``yes|no``] [--auto-promote]
361 | [-s *secondary_ip*]
362 | [--node-parameters *ndparams*]
363 | [--node-powered=``yes|no``]
366 This command changes the role of the node. Each options takes
367 either a literal yes or no, and only one option should be given as
368 yes. The meaning of the roles and flags are described in the
369 manpage **ganeti**(7).
371 ``--node-powered`` can be used to modify state-of-record if it doesn't reflect
374 In case a node is demoted from the master candidate role, the
375 operation will be refused unless you pass the ``--auto-promote``
376 option. This option will cause the operation to lock all cluster nodes
377 (thus it will not be able to run in parallel with most other jobs),
378 but it allows automated maintenance of the cluster candidate pool. If
379 locking all cluster node is too expensive, another option is to
380 promote manually another node to master candidate before demoting the
383 Example (setting a node offline, which will demote it from master
384 candidate role if is in that role)::
386 # gnt-node modify --offline=yes node1.example.com
388 The ``-s`` can be used to change the node's secondary ip. No drbd
389 instances can be running on the node, while this operation is
392 Example (setting the node back to online and master candidate)::
394 # gnt-node modify --offline=no --master-candidate=yes node1.example.com
400 **remove** {*nodename*}
402 Removes a node from the cluster. Instances must be removed or
403 migrated to another cluster before.
407 # gnt-node remove node5.example.com
413 **remove-tags** [--from *file*] {*nodename*} {*tag*...}
415 Remove tags from the given node. If any of the tags are not
416 existing on the node, the entire operation will abort.
418 If the ``--from`` option is given, the list of tags to be removed will
419 be extended with the contents of that file (each line becomes a tag).
420 In this case, there is not need to pass tags on the command line (if
421 you do, tags from both sources will be removed). A file name of - will
422 be interpreted as stdin.
427 | **volumes** [--no-headers] [--human-readable]
428 | [--separator=*SEPARATOR*] [--output=*FIELDS*]
431 Lists all logical volumes and their physical disks from the node(s)
434 The ``--no-headers`` option will skip the initial header line. The
435 ``--separator`` option takes an argument which denotes what will be
436 used between the output fields. Both these options are to help
439 The units used to display the numeric values in the output varies,
440 depending on the options given. By default, the values will be
441 formatted in the most appropriate unit. If the ``--separator``
442 option is given, then the values are shown in mebibytes to allow
443 parsing by scripts. In both cases, the ``--units`` option can be
444 used to enforce a given output unit.
446 The ``-o`` option takes a comma-separated list of output fields.
447 The available fields and their meaning are:
450 the node name on which the volume exists
453 the physical drive (on which the LVM physical volume lives)
456 the volume group name
459 the logical volume name
462 the logical volume size
465 The name of the instance to which this volume belongs, or (in case
466 it's an orphan volume) the character "-"
471 # gnt-node volumes node5.example.com
472 Node PhysDev VG Name Size Instance
473 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11000.meta 128 instance1.example.com
474 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11001.data 256 instance1.example.com
480 | **list-storage** [--no-headers] [--human-readable]
481 | [--separator=*SEPARATOR*] [--storage-type=*STORAGE\_TYPE*]
482 | [--output=*FIELDS*]
485 Lists the available storage units and their details for the given
488 The ``--no-headers`` option will skip the initial header line. The
489 ``--separator`` option takes an argument which denotes what will be
490 used between the output fields. Both these options are to help
493 The units used to display the numeric values in the output varies,
494 depending on the options given. By default, the values will be
495 formatted in the most appropriate unit. If the ``--separator``
496 option is given, then the values are shown in mebibytes to allow
497 parsing by scripts. In both cases, the ``--units`` option can be
498 used to enforce a given output unit.
500 The ``--storage-type`` option can be used to choose a storage unit
501 type. Possible choices are lvm-pv, lvm-vg or file.
503 The ``-o`` option takes a comma-separated list of output fields.
504 The available fields and their meaning are:
507 the node name on which the volume exists
510 the type of the storage unit (currently just what is passed in via
514 the path/identifier of the storage unit
517 total size of the unit; for the file type see a note below
520 used space in the unit; for the file type see a note below
526 whether we the unit is available for allocation (only lvm-pv can
527 change this setting, the other types always report true)
530 Note that for the "file" type, the total disk space might not equal
531 to the sum of used and free, due to the method Ganeti uses to
532 compute each of them. The total and free values are computed as the
533 total and free space values for the filesystem to which the
534 directory belongs, but the used space is computed from the used
535 space under that directory *only*, which might not be necessarily
536 the root of the filesystem, and as such there could be files
537 outside the file storage directory using disk space and causing a
538 mismatch in the values.
542 node1# gnt-node list-storage node2
543 Node Type Name Size Used Free Allocatable
544 node2 lvm-pv /dev/sda7 673.8G 1.5G 672.3G Y
545 node2 lvm-pv /dev/sdb1 698.6G 0M 698.6G Y
551 **modify-storage** [``--allocatable=yes|no``]
552 {*node*} {*storage-type*} {*volume-name*}
554 Modifies storage volumes on a node. Only LVM physical volumes can
555 be modified at the moment. They have a storage type of "lvm-pv".
559 # gnt-node modify-storage --allocatable no node5.example.com lvm-pv /dev/sdb1
565 **repair-storage** [--ignore-consistency] {*node*} {*storage-type*}
568 Repairs a storage volume on a node. Only LVM volume groups can be
569 repaired at this time. They have the storage type "lvm-vg".
571 On LVM volume groups, **repair-storage** runs "vgreduce
576 **Caution:** Running this command can lead to data loss. Use it with
579 The ``--ignore-consistency`` option will ignore any inconsistent
580 disks (on the nodes paired with this one). Use of this option is
581 most likely to lead to data-loss.
585 # gnt-node repair-storage node5.example.com lvm-vg xenvg
591 **powercycle** [``--yes``] [``--force``] {*node*}
593 This commands (tries to) forcefully reboot a node. It is a command
594 that can be used if the node environemnt is broken, such that the
595 admin can no longer login over ssh, but the Ganeti node daemon is
598 Note that this command is not guaranteed to work; it depends on the
599 hypervisor how effective is the reboot attempt. For Linux, this
600 command require that the kernel option CONFIG\_MAGIC\_SYSRQ is
603 The ``--yes`` option can be used to skip confirmation, while the
604 ``--force`` option is needed if the target node is the master
610 **power** on|off|cycle|status {*node*}
612 This commands calls out to out-of-band management to change the power
613 state of given node. With ``status`` you get the power status as reported
614 by the out-of-band managment script.