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``]
30 Adds the given node to the cluster.
32 This command is used to join a new node to the cluster. You will
33 have to provide the password for root of the node to be able to add
34 the node in the cluster. The command needs to be run on the Ganeti
37 Note that the command is potentially destructive, as it will
38 forcibly join the specified host the cluster, not paying attention
39 to its current status (it could be already in a cluster, etc.)
41 The ``-s`` is used in dual-home clusters and specifies the new node's
42 IP in the secondary network. See the discussion in **gnt-cluster**(8)
45 In case you're readding a node after hardware failure, you can use
46 the ``--readd`` parameter. In this case, you don't need to pass the
47 secondary IP again, it will reused from the cluster. Also, the
48 drained and offline flags of the node will be cleared before
51 The ``-g`` is used to add the new node into a specific node group,
52 specified by UUID or name. If only one node group exists you can
53 skip this option, otherwise it's mandatory.
55 The ``vm_capable`` and ``master_capable`` options are described in
56 **ganeti**(7), and are used to set the properties of the new node.
60 # gnt-node add node5.example.com
61 # gnt-node add -s 192.0.2.5 node5.example.com
62 # gnt-node add -g group2 -s 192.0.2.9 node9.group2.example.com
68 **add-tags** [--from *file*] {*nodename*} {*tag*...}
70 Add tags to the given node. If any of the tags contains invalid
71 characters, the entire operation will abort.
73 If the ``--from`` option is given, the list of tags will be
74 extended with the contents of that file (each line becomes a tag).
75 In this case, there is not need to pass tags on the command line
76 (if you do, both sources will be used). A file name of - will be
82 **evacuate** [-f] [--early-release] [--iallocator *NAME* \|
83 --new-secondary *destination\_node*] {*node*...}
85 This command will move all secondary instances away from the given
86 node(s). It works only for instances having a drbd disk template.
88 The new location for the instances can be specified in two ways:
90 - as a single node for all instances, via the ``--new-secondary``
93 - or via the ``--iallocator`` option, giving a script name as
94 parameter, so each instance will be in turn placed on the (per the
98 The ``--early-release`` changes the code so that the old storage on
99 node being evacuated is removed early (before the resync is
100 completed) and the internal Ganeti locks are also released for both
101 the current secondary and the new secondary, thus allowing more
102 parallelism in the cluster operation. This should be used only when
103 recovering from a disk failure on the current secondary (thus the
104 old storage is already broken) or when the storage on the primary
105 node is known to be fine (thus we won't need the old storage for
110 # gnt-node evacuate -I dumb node3.example.com
116 **failover** [-f] [--ignore-consistency] {*node*}
118 This command will fail over all instances having the given node as
119 primary to their secondary nodes. This works only for instances having
120 a drbd disk template.
122 Normally the failover will check the consistency of the disks before
123 failing over the instance. If you are trying to migrate instances off
124 a dead node, this will fail. Use the ``--ignore-consistency`` option
129 # gnt-node failover node1.example.com
137 Show detailed information about the nodes in the cluster. If you
138 don't give any arguments, all nodes will be shows, otherwise the
139 output will be restricted to the given names.
145 | [--no-headers] [--separator=*SEPARATOR*]
146 | [--units=*UNITS*] [-o *[+]FIELD,...*]
150 Lists the nodes in the cluster.
152 The ``--no-headers`` option will skip the initial header line. The
153 ``--separator`` option takes an argument which denotes what will be
154 used between the output fields. Both these options are to help
157 The units used to display the numeric values in the output varies,
158 depending on the options given. By default, the values will be
159 formatted in the most appropriate unit. If the ``--separator``
160 option is given, then the values are shown in mebibytes to allow
161 parsing by scripts. In both cases, the ``--units`` option can be
162 used to enforce a given output unit.
164 By default, the query of nodes will be done in parallel with any
165 running jobs. This might give inconsistent results for the free
166 disk/memory. The ``--sync`` can be used to grab locks for all the
167 nodes and ensure consistent view of the cluster (but this might
168 stall the query for a long time).
170 Passing the ``--roman`` option gnt-node list will try to output
171 some of its fields in a latin-friendly way. This is not the default
172 for backwards compatibility.
174 The ``-o`` option takes a comma-separated list of output fields.
175 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.
323 **list-tags** {*nodename*}
325 List the tags of the given node.
330 **migrate** [-f] [--non-live] [--migration-mode=live\|non-live]
333 This command will migrate all instances having the given node as
334 primary to their secondary nodes. This works only for instances
335 having a drbd disk template.
337 As for the **gnt-instance migrate** command, the options
338 ``--no-live`` and ``--migration-mode`` can be given to influence
343 # gnt-node migrate node1.example.com
349 | **modify** [-f] [--submit]
350 | [--master-candidate=``yes|no``] [--drained=``yes|no``] [--offline=``yes|no``]
351 | [--master-capable=``yes|no``] [--vm-capable=``yes|no``] [--auto-promote]
352 | [-s *secondary_ip*]
355 This command changes the role of the node. Each options takes
356 either a literal yes or no, and only one option should be given as
357 yes. The meaning of the roles and flags are described in the
358 manpage **ganeti**(7).
360 In case a node is demoted from the master candidate role, the
361 operation will be refused unless you pass the ``--auto-promote``
362 option. This option will cause the operation to lock all cluster nodes
363 (thus it will not be able to run in parallel with most other jobs),
364 but it allows automated maintenance of the cluster candidate pool. If
365 locking all cluster node is too expensive, another option is to
366 promote manually another node to master candidate before demoting the
369 Example (setting a node offline, which will demote it from master
370 candidate role if is in that role)::
372 # gnt-node modify --offline=yes node1.example.com
374 The ``-s`` can be used to change the node's secondary ip. No drbd
375 instances can be running on the node, while this operation is
378 Example (setting the node back to online and master candidate)::
380 # gnt-node modify --offline=no --master-candidate=yes node1.example.com
386 **remove** {*nodename*}
388 Removes a node from the cluster. Instances must be removed or
389 migrated to another cluster before.
393 # gnt-node remove node5.example.com
399 **remove-tags** [--from *file*] {*nodename*} {*tag*...}
401 Remove tags from the given node. If any of the tags are not
402 existing on the node, the entire operation will abort.
404 If the ``--from`` option is given, the list of tags to be removed will
405 be extended with the contents of that file (each line becomes a tag).
406 In this case, there is not need to pass tags on the command line (if
407 you do, tags from both sources will be removed). A file name of - will
408 be interpreted as stdin.
413 | **volumes** [--no-headers] [--human-readable]
414 | [--separator=*SEPARATOR*] [--output=*FIELDS*]
417 Lists all logical volumes and their physical disks from the node(s)
420 The ``--no-headers`` option will skip the initial header line. The
421 ``--separator`` option takes an argument which denotes what will be
422 used between the output fields. Both these options are to help
425 The units used to display the numeric values in the output varies,
426 depending on the options given. By default, the values will be
427 formatted in the most appropriate unit. If the ``--separator``
428 option is given, then the values are shown in mebibytes to allow
429 parsing by scripts. In both cases, the ``--units`` option can be
430 used to enforce a given output unit.
432 The ``-o`` option takes a comma-separated list of output fields.
433 The available fields and their meaning are:
436 the node name on which the volume exists
439 the physical drive (on which the LVM physical volume lives)
442 the volume group name
445 the logical volume name
448 the logical volume size
451 The name of the instance to which this volume belongs, or (in case
452 it's an orphan volume) the character "-"
457 # gnt-node volumes node5.example.com
458 Node PhysDev VG Name Size Instance
459 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11000.meta 128 instance1.example.com
460 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11001.data 256 instance1.example.com
466 | **list-storage** [--no-headers] [--human-readable]
467 | [--separator=*SEPARATOR*] [--storage-type=*STORAGE\_TYPE*]
468 | [--output=*FIELDS*]
471 Lists the available storage units and their details for the given
474 The ``--no-headers`` option will skip the initial header line. The
475 ``--separator`` option takes an argument which denotes what will be
476 used between the output fields. Both these options are to help
479 The units used to display the numeric values in the output varies,
480 depending on the options given. By default, the values will be
481 formatted in the most appropriate unit. If the ``--separator``
482 option is given, then the values are shown in mebibytes to allow
483 parsing by scripts. In both cases, the ``--units`` option can be
484 used to enforce a given output unit.
486 The ``--storage-type`` option can be used to choose a storage unit
487 type. Possible choices are lvm-pv, lvm-vg or file.
489 The ``-o`` option takes a comma-separated list of output fields.
490 The available fields and their meaning are:
493 the node name on which the volume exists
496 the type of the storage unit (currently just what is passed in via
500 the path/identifier of the storage unit
503 total size of the unit; for the file type see a note below
506 used space in the unit; for the file type see a note below
512 whether we the unit is available for allocation (only lvm-pv can
513 change this setting, the other types always report true)
516 Note that for the "file" type, the total disk space might not equal
517 to the sum of used and free, due to the method Ganeti uses to
518 compute each of them. The total and free values are computed as the
519 total and free space values for the filesystem to which the
520 directory belongs, but the used space is computed from the used
521 space under that directory *only*, which might not be necessarily
522 the root of the filesystem, and as such there could be files
523 outside the file storage directory using disk space and causing a
524 mismatch in the values.
528 node1# gnt-node list-storage node2
529 Node Type Name Size Used Free Allocatable
530 node2 lvm-pv /dev/sda7 673.8G 1.5G 672.3G Y
531 node2 lvm-pv /dev/sdb1 698.6G 0M 698.6G Y
537 **modify-storage** [``--allocatable=yes|no``]
538 {*node*} {*storage-type*} {*volume-name*}
540 Modifies storage volumes on a node. Only LVM physical volumes can
541 be modified at the moment. They have a storage type of "lvm-pv".
545 # gnt-node modify-storage --allocatable no node5.example.com lvm-pv /dev/sdb1
551 **repair-storage** [--ignore-consistency] {*node*} {*storage-type*}
554 Repairs a storage volume on a node. Only LVM volume groups can be
555 repaired at this time. They have the storage type "lvm-vg".
557 On LVM volume groups, **repair-storage** runs "vgreduce
562 **Caution:** Running this command can lead to data loss. Use it with
565 The ``--ignore-consistency`` option will ignore any inconsistent
566 disks (on the nodes paired with this one). Use of this option is
567 most likely to lead to data-loss.
571 # gnt-node repair-storage node5.example.com lvm-vg xenvg
577 **powercycle** [``--yes``] [``--force``] {*node*}
579 This commands (tries to) forcefully reboot a node. It is a command
580 that can be used if the node environemnt is broken, such that the
581 admin can no longer login over ssh, but the Ganeti node daemon is
584 Note that this command is not guaranteed to work; it depends on the
585 hypervisor how effective is the reboot attempt. For Linux, this
586 command require that the kernel option CONFIG\_MAGIC\_SYSRQ is
589 The ``--yes`` option can be used to skip confirmation, while the
590 ``--force`` option is needed if the target node is the master