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 ``-g`` is used to add the new node into a specific node group,
53 specified by UUID or name. If only one node group exists you can
54 skip this option, otherwise it's mandatory.
56 The ``vm_capable``, ``master_capable`` and ``ndparams`` options are
57 described in **ganeti**(7), and are used to set the properties of the
62 # gnt-node add node5.example.com
63 # gnt-node add -s 192.0.2.5 node5.example.com
64 # gnt-node add -g group2 -s 192.0.2.9 node9.group2.example.com
70 **add-tags** [--from *file*] {*nodename*} {*tag*...}
72 Add tags to the given node. If any of the tags contains invalid
73 characters, the entire operation will abort.
75 If the ``--from`` option is given, the list of tags will be
76 extended with the contents of that file (each line becomes a tag).
77 In this case, there is not need to pass tags on the command line
78 (if you do, both sources will be used). A file name of - will be
84 **evacuate** [-f] [--early-release] [--iallocator *NAME* \|
85 --new-secondary *destination\_node*] {*node*...}
87 This command will move all secondary instances away from the given
88 node(s). It works only for instances having a drbd disk template.
90 The new location for the instances can be specified in two ways:
92 - as a single node for all instances, via the ``--new-secondary``
95 - or via the ``--iallocator`` option, giving a script name as
96 parameter, so each instance will be in turn placed on the (per the
100 The ``--early-release`` changes the code so that the old storage on
101 node being evacuated is removed early (before the resync is
102 completed) and the internal Ganeti locks are also released for both
103 the current secondary and the new secondary, thus allowing more
104 parallelism in the cluster operation. This should be used only when
105 recovering from a disk failure on the current secondary (thus the
106 old storage is already broken) or when the storage on the primary
107 node is known to be fine (thus we won't need the old storage for
112 # gnt-node evacuate -I dumb node3.example.com
118 **failover** [-f] [--ignore-consistency] {*node*}
120 This command will fail over all instances having the given node as
121 primary to their secondary nodes. This works only for instances having
122 a drbd disk template.
124 Normally the failover will check the consistency of the disks before
125 failing over the instance. If you are trying to migrate instances off
126 a dead node, this will fail. Use the ``--ignore-consistency`` option
131 # gnt-node failover node1.example.com
139 Show detailed information about the nodes in the cluster. If you
140 don't give any arguments, all nodes will be shows, otherwise the
141 output will be restricted to the given names.
147 | [--no-headers] [--separator=*SEPARATOR*]
148 | [--units=*UNITS*] [-o *[+]FIELD,...*]
151 Lists the nodes in the cluster.
153 The ``--no-headers`` option will skip the initial header line. The
154 ``--separator`` option takes an argument which denotes what will be
155 used between the output fields. Both these options are to help
158 The units used to display the numeric values in the output varies,
159 depending on the options given. By default, the values will be
160 formatted in the most appropriate unit. If the ``--separator``
161 option is given, then the values are shown in mebibytes to allow
162 parsing by scripts. In both cases, the ``--units`` option can be
163 used to enforce a given output unit.
165 Queries of nodes will be done in parallel with any running jobs. This might
166 give inconsistent results for the free disk/memory.
168 The ``-o`` option takes a comma-separated list of output fields.
169 The available fields and their meaning are:
177 the number of instances having this node as primary
180 the list of instances having this node as primary, comma separated
183 the number of instances having this node as a secondary node
186 the list of instances having this node as a secondary node, comma
190 the primary ip of this node (used for cluster communication)
193 the secondary ip of this node (used for data replication in dual-ip
194 clusters, see gnt-cluster(8)
197 total disk space in the volume group used for instance disk
201 available disk space in the volume group
204 total memory on the physical node
207 the memory used by the node itself
210 memory available for instance allocations
213 the node bootid value; this is a linux specific feature that
214 assigns a new UUID to the node at each boot and can be use to
215 detect node reboots (by tracking changes in this value)
218 comma-separated list of the node's tags
221 the so called 'serial number' of the node; this is a numeric field
222 that is incremented each time the node is modified, and it can be
223 used to detect modifications
226 the creation time of the node; note that this field contains spaces
227 and as such it's harder to parse
229 if this attribute is not present (e.g. when upgrading from older
230 versions), then "N/A" will be shown instead
233 the last modification time of the node; note that this field
234 contains spaces and as such it's harder to parse
236 if this attribute is not present (e.g. when upgrading from older
237 versions), then "N/A" will be shown instead
240 Show the UUID of the node (generated automatically by Ganeti)
243 the toal number of logical processors
246 the number of NUMA domains on the node, if the hypervisor can
247 export this information
250 the number of physical CPU sockets, if the hypervisor can export
254 whether the node is a master candidate or not
257 whether the node is drained or not; the cluster still communicates
258 with drained nodes but excludes them from allocation operations
261 whether the node is offline or not; if offline, the cluster does
262 not communicate with offline nodes; useful for nodes that are not
263 reachable in order to avoid delays
266 A condensed version of the node flags; this field will output a
267 one-character field, with the following possible values:
269 - *M* for the master node
271 - *C* for a master candidate
273 - *R* for a regular node
275 - *D* for a drained node
277 - *O* for an offline node
280 whether the node can become a master candidate
283 whether the node can host instances
286 the name of the node's group, if known (the query is done without
287 locking, so data consistency is not guaranteed)
290 the UUID of the node's group
293 If the value of the option starts with the character ``+``, the new
294 fields will be added to the default list. This allows to quickly
295 see the default list plus a few other fields, instead of retyping
296 the entire list of fields.
298 Note that some of this fields are known from the configuration of
299 the cluster (e.g. name, pinst, sinst, pip, sip and thus the master
300 does not need to contact the node for this data (making the listing
301 fast if only fields from this set are selected), whereas the other
302 fields are "live" fields and we need to make a query to the cluster
305 Depending on the virtualization type and implementation details,
306 the mtotal, mnode and mfree may have slighly varying meanings. For
307 example, some solutions share the node memory with the pool of
308 memory used for instances (KVM), whereas others have separate
309 memory for the node and for the instances (Xen).
311 If no node names are given, then all nodes are queried. Otherwise,
312 only the given nodes will be listed.
318 **list-fields** [field...]
320 Lists available fields for nodes.
326 **list-tags** {*nodename*}
328 List the tags of the given node.
333 **migrate** [-f] [--non-live] [--migration-mode=live\|non-live]
336 This command will migrate all instances having the given node as
337 primary to their secondary nodes. This works only for instances
338 having a drbd disk template.
340 As for the **gnt-instance migrate** command, the options
341 ``--no-live`` and ``--migration-mode`` can be given to influence
346 # gnt-node migrate node1.example.com
352 | **modify** [-f] [--submit]
353 | [--master-candidate=``yes|no``] [--drained=``yes|no``] [--offline=``yes|no``]
354 | [--master-capable=``yes|no``] [--vm-capable=``yes|no``] [--auto-promote]
355 | [-s *secondary_ip*]
356 | [--node-parameters *ndparams*]
357 | [--node-powered=``yes|no``]
360 This command changes the role of the node. Each options takes
361 either a literal yes or no, and only one option should be given as
362 yes. The meaning of the roles and flags are described in the
363 manpage **ganeti**(7).
365 ``--node-powered`` can be used to modify state-of-record if it doesn't reflect
368 In case a node is demoted from the master candidate role, the
369 operation will be refused unless you pass the ``--auto-promote``
370 option. This option will cause the operation to lock all cluster nodes
371 (thus it will not be able to run in parallel with most other jobs),
372 but it allows automated maintenance of the cluster candidate pool. If
373 locking all cluster node is too expensive, another option is to
374 promote manually another node to master candidate before demoting the
377 Example (setting a node offline, which will demote it from master
378 candidate role if is in that role)::
380 # gnt-node modify --offline=yes node1.example.com
382 The ``-s`` can be used to change the node's secondary ip. No drbd
383 instances can be running on the node, while this operation is
386 Example (setting the node back to online and master candidate)::
388 # gnt-node modify --offline=no --master-candidate=yes node1.example.com
394 **remove** {*nodename*}
396 Removes a node from the cluster. Instances must be removed or
397 migrated to another cluster before.
401 # gnt-node remove node5.example.com
407 **remove-tags** [--from *file*] {*nodename*} {*tag*...}
409 Remove tags from the given node. If any of the tags are not
410 existing on the node, the entire operation will abort.
412 If the ``--from`` option is given, the list of tags to be removed will
413 be extended with the contents of that file (each line becomes a tag).
414 In this case, there is not need to pass tags on the command line (if
415 you do, tags from both sources will be removed). A file name of - will
416 be interpreted as stdin.
421 | **volumes** [--no-headers] [--human-readable]
422 | [--separator=*SEPARATOR*] [--output=*FIELDS*]
425 Lists all logical volumes and their physical disks from the node(s)
428 The ``--no-headers`` option will skip the initial header line. The
429 ``--separator`` option takes an argument which denotes what will be
430 used between the output fields. Both these options are to help
433 The units used to display the numeric values in the output varies,
434 depending on the options given. By default, the values will be
435 formatted in the most appropriate unit. If the ``--separator``
436 option is given, then the values are shown in mebibytes to allow
437 parsing by scripts. In both cases, the ``--units`` option can be
438 used to enforce a given output unit.
440 The ``-o`` option takes a comma-separated list of output fields.
441 The available fields and their meaning are:
444 the node name on which the volume exists
447 the physical drive (on which the LVM physical volume lives)
450 the volume group name
453 the logical volume name
456 the logical volume size
459 The name of the instance to which this volume belongs, or (in case
460 it's an orphan volume) the character "-"
465 # gnt-node volumes node5.example.com
466 Node PhysDev VG Name Size Instance
467 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11000.meta 128 instance1.example.com
468 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11001.data 256 instance1.example.com
474 | **list-storage** [--no-headers] [--human-readable]
475 | [--separator=*SEPARATOR*] [--storage-type=*STORAGE\_TYPE*]
476 | [--output=*FIELDS*]
479 Lists the available storage units and their details for the given
482 The ``--no-headers`` option will skip the initial header line. The
483 ``--separator`` option takes an argument which denotes what will be
484 used between the output fields. Both these options are to help
487 The units used to display the numeric values in the output varies,
488 depending on the options given. By default, the values will be
489 formatted in the most appropriate unit. If the ``--separator``
490 option is given, then the values are shown in mebibytes to allow
491 parsing by scripts. In both cases, the ``--units`` option can be
492 used to enforce a given output unit.
494 The ``--storage-type`` option can be used to choose a storage unit
495 type. Possible choices are lvm-pv, lvm-vg or file.
497 The ``-o`` option takes a comma-separated list of output fields.
498 The available fields and their meaning are:
501 the node name on which the volume exists
504 the type of the storage unit (currently just what is passed in via
508 the path/identifier of the storage unit
511 total size of the unit; for the file type see a note below
514 used space in the unit; for the file type see a note below
520 whether we the unit is available for allocation (only lvm-pv can
521 change this setting, the other types always report true)
524 Note that for the "file" type, the total disk space might not equal
525 to the sum of used and free, due to the method Ganeti uses to
526 compute each of them. The total and free values are computed as the
527 total and free space values for the filesystem to which the
528 directory belongs, but the used space is computed from the used
529 space under that directory *only*, which might not be necessarily
530 the root of the filesystem, and as such there could be files
531 outside the file storage directory using disk space and causing a
532 mismatch in the values.
536 node1# gnt-node list-storage node2
537 Node Type Name Size Used Free Allocatable
538 node2 lvm-pv /dev/sda7 673.8G 1.5G 672.3G Y
539 node2 lvm-pv /dev/sdb1 698.6G 0M 698.6G Y
545 **modify-storage** [``--allocatable=yes|no``]
546 {*node*} {*storage-type*} {*volume-name*}
548 Modifies storage volumes on a node. Only LVM physical volumes can
549 be modified at the moment. They have a storage type of "lvm-pv".
553 # gnt-node modify-storage --allocatable no node5.example.com lvm-pv /dev/sdb1
559 **repair-storage** [--ignore-consistency] {*node*} {*storage-type*}
562 Repairs a storage volume on a node. Only LVM volume groups can be
563 repaired at this time. They have the storage type "lvm-vg".
565 On LVM volume groups, **repair-storage** runs "vgreduce
570 **Caution:** Running this command can lead to data loss. Use it with
573 The ``--ignore-consistency`` option will ignore any inconsistent
574 disks (on the nodes paired with this one). Use of this option is
575 most likely to lead to data-loss.
579 # gnt-node repair-storage node5.example.com lvm-vg xenvg
585 **powercycle** [``--yes``] [``--force``] {*node*}
587 This commands (tries to) forcefully reboot a node. It is a command
588 that can be used if the node environemnt is broken, such that the
589 admin can no longer login over ssh, but the Ganeti node daemon is
592 Note that this command is not guaranteed to work; it depends on the
593 hypervisor how effective is the reboot attempt. For Linux, this
594 command require that the kernel option CONFIG\_MAGIC\_SYSRQ is
597 The ``--yes`` option can be used to skip confirmation, while the
598 ``--force`` option is needed if the target node is the master
604 **power** on|off|cycle|status {*node*}
606 This commands calls out to out-of-band management to change the power
607 state of given node. With ``status`` you get the power status as reported
608 by the out-of-band managment script.
615 This commands calls out to out-pf-band management to ask for the health status
616 of all or given nodes. The health contains the node name and then the items
617 element with their status in a ``item=status`` manner. Where ``item`` is script
618 specific and ``status`` can be one of ``OK``, ``WARNING``, ``CRITICAL`` or
619 ``UNKNOWN``. Items with status ``WARNING`` or ``CRITICAL`` are logged and
620 annotated in the command line output.