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} *secondary\_ip*]
27 | [{-g|--node-group} *nodegroup*]
28 | [--master-capable=``yes|no``] [--vm-capable=``yes|no``]
29 | [--node-parameters *ndparams*]
32 Adds the given node to the cluster.
34 This command is used to join a new node to the cluster. You will
35 have to provide the password for root of the node to be able to add
36 the node in the cluster. The command needs to be run on the Ganeti
39 Note that the command is potentially destructive, as it will
40 forcibly join the specified host the cluster, not paying attention
41 to its current status (it could be already in a cluster, etc.)
43 The ``-s (--secondary-ip)`` is used in dual-home clusters and
44 specifies the new node's IP in the secondary network. See the
45 discussion in **gnt-cluster**(8) for more information.
47 In case you're readding a node after hardware failure, you can use
48 the ``--readd`` parameter. In this case, you don't need to pass the
49 secondary IP again, it will reused from the cluster. Also, the
50 drained and offline flags of the node will be cleared before
53 The ``--force-join`` option is to proceed with adding a node even if it already
54 appears to belong to another cluster. This is used during cluster merging, for
57 The ``-g (--node-group)`` option is used to add the new node into a
58 specific node group, specified by UUID or name. If only one node group
59 exists you can skip this option, otherwise it's mandatory.
61 The ``vm_capable``, ``master_capable`` and ``ndparams`` options are
62 described in **ganeti**(7), and are used to set the properties of the
67 # gnt-node add node5.example.com
68 # gnt-node add -s 192.0.2.5 node5.example.com
69 # gnt-node add -g group2 -s 192.0.2.9 node9.group2.example.com
75 **add-tags** [--from *file*] {*nodename*} {*tag*...}
77 Add tags to the given node. If any of the tags contains invalid
78 characters, the entire operation will abort.
80 If the ``--from`` option is given, the list of tags will be
81 extended with the contents of that file (each line becomes a tag).
82 In this case, there is not need to pass tags on the command line
83 (if you do, both sources will be used). A file name of - will be
89 **evacuate** [-f] [--early-release] [--iallocator *NAME* \|
90 --new-secondary *destination\_node*] {*node*...}
92 This command will move all secondary instances away from the given
93 node(s). It works only for instances having a drbd disk template.
95 The new location for the instances can be specified in two ways:
97 - as a single node for all instances, via the ``-n (--new-secondary)``
100 - or via the ``-I (--iallocator)`` option, giving a script name as
101 parameter, so each instance will be in turn placed on the (per the
105 The ``--early-release`` changes the code so that the old storage on
106 node being evacuated is removed early (before the resync is
107 completed) and the internal Ganeti locks are also released for both
108 the current secondary and the new secondary, thus allowing more
109 parallelism in the cluster operation. This should be used only when
110 recovering from a disk failure on the current secondary (thus the
111 old storage is already broken) or when the storage on the primary
112 node is known to be fine (thus we won't need the old storage for
117 # gnt-node evacuate -I hail node3.example.com
123 **failover** [-f] [--ignore-consistency] {*node*}
125 This command will fail over all instances having the given node as
126 primary to their secondary nodes. This works only for instances having
127 a drbd disk template.
129 Normally the failover will check the consistency of the disks before
130 failing over the instance. If you are trying to migrate instances off
131 a dead node, this will fail. Use the ``--ignore-consistency`` option
136 # gnt-node failover node1.example.com
144 Show detailed information about the nodes in the cluster. If you
145 don't give any arguments, all nodes will be shows, otherwise the
146 output will be restricted to the given names.
152 | [--no-headers] [--separator=*SEPARATOR*]
153 | [--units=*UNITS*] [-v] [{-o|--output} *[+]FIELD,...*]
156 Lists the nodes in the cluster.
158 The ``--no-headers`` option will skip the initial header line. The
159 ``--separator`` option takes an argument which denotes what will be
160 used between the output fields. Both these options are to help
163 The units used to display the numeric values in the output varies,
164 depending on the options given. By default, the values will be
165 formatted in the most appropriate unit. If the ``--separator``
166 option is given, then the values are shown in mebibytes to allow
167 parsing by scripts. In both cases, the ``--units`` option can be
168 used to enforce a given output unit.
170 Queries of nodes will be done in parallel with any running jobs. This might
171 give inconsistent results for the free disk/memory.
173 The ``-v`` option activates verbose mode, which changes the display of
174 special field states (see **ganeti(7)**).
176 The ``-o (--output)`` option takes a comma-separated list of output
177 fields. The available fields and their meaning are:
184 the number of instances having this node as primary
187 the list of instances having this node as primary, comma separated
190 the number of instances having this node as a secondary node
193 the list of instances having this node as a secondary node, comma
197 the primary ip of this node (used for cluster communication)
200 the secondary ip of this node (used for data replication in dual-ip
201 clusters, see gnt-cluster(8)
204 total disk space in the volume group used for instance disk
208 available disk space in the volume group
211 total memory on the physical node
214 the memory used by the node itself
217 memory available for instance allocations
220 the node bootid value; this is a linux specific feature that
221 assigns a new UUID to the node at each boot and can be use to
222 detect node reboots (by tracking changes in this value)
225 comma-separated list of the node's tags
228 the so called 'serial number' of the node; this is a numeric field
229 that is incremented each time the node is modified, and it can be
230 used to detect modifications
233 the creation time of the node; note that this field contains spaces
234 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 the last modification time of the node; note that this field
241 contains spaces and as such it's harder to parse
243 if this attribute is not present (e.g. when upgrading from older
244 versions), then "N/A" will be shown instead
247 Show the UUID of the node (generated automatically by Ganeti)
250 the toal number of logical processors
253 the number of NUMA domains on the node, if the hypervisor can
254 export this information
257 the number of physical CPU sockets, if the hypervisor can export
261 whether the node is a master candidate or not
264 whether the node is drained or not; the cluster still communicates
265 with drained nodes but excludes them from allocation operations
268 whether the node is offline or not; if offline, the cluster does
269 not communicate with offline nodes; useful for nodes that are not
270 reachable in order to avoid delays
273 A condensed version of the node flags; this field will output a
274 one-character field, with the following possible values:
276 - *M* for the master node
278 - *C* for a master candidate
280 - *R* for a regular node
282 - *D* for a drained node
284 - *O* for an offline node
287 whether the node can become a master candidate
290 whether the node can host instances
293 the name of the node's group, if known (the query is done without
294 locking, so data consistency is not guaranteed)
297 the UUID of the node's group
300 If the value of the option starts with the character ``+``, the new
301 fields will be added to the default list. This allows one to quickly
302 see the default list plus a few other fields, instead of retyping
303 the entire list of fields.
305 Note that some of this fields are known from the configuration of
306 the cluster (e.g. name, pinst, sinst, pip, sip and thus the master
307 does not need to contact the node for this data (making the listing
308 fast if only fields from this set are selected), whereas the other
309 fields are "live" fields and we need to make a query to the cluster
312 Depending on the virtualization type and implementation details,
313 the mtotal, mnode and mfree may have slighly varying meanings. For
314 example, some solutions share the node memory with the pool of
315 memory used for instances (KVM), whereas others have separate
316 memory for the node and for the instances (Xen).
318 If no node names are given, then all nodes are queried. Otherwise,
319 only the given nodes will be listed.
325 **list-fields** [field...]
327 Lists available fields for nodes.
333 **list-tags** {*nodename*}
335 List the tags of the given node.
340 **migrate** [-f] [--non-live] [--migration-mode=live\|non-live]
343 This command will migrate all instances having the given node as
344 primary to their secondary nodes. This works only for instances
345 having a drbd disk template.
347 As for the **gnt-instance migrate** command, the options
348 ``--no-live`` and ``--migration-mode`` can be given to influence
353 # gnt-node migrate node1.example.com
359 | **modify** [-f] [--submit]
360 | [{-C|--master-candidate} ``yes|no``]
361 | [{-D|--drained} ``yes|no``] [{-O|--offline} ``yes|no``]
362 | [--master-capable=``yes|no``] [--vm-capable=``yes|no``] [--auto-promote]
363 | [{-s|--secondary-ip} *secondary_ip*]
364 | [--node-parameters *ndparams*]
365 | [--node-powered=``yes|no``]
368 This command changes the role of the node. Each options takes
369 either a literal yes or no, and only one option should be given as
370 yes. The meaning of the roles and flags are described in the
371 manpage **ganeti**(7).
373 The option ``--node-powered`` can be used to modify state-of-record if
374 it doesn't reflect the reality anymore.
376 In case a node is demoted from the master candidate role, the
377 operation will be refused unless you pass the ``--auto-promote``
378 option. This option will cause the operation to lock all cluster nodes
379 (thus it will not be able to run in parallel with most other jobs),
380 but it allows automated maintenance of the cluster candidate pool. If
381 locking all cluster node is too expensive, another option is to
382 promote manually another node to master candidate before demoting the
385 Example (setting a node offline, which will demote it from master
386 candidate role if is in that role)::
388 # gnt-node modify --offline=yes node1.example.com
390 The ``-s (--secondary-ip)`` option can be used to change the node's
391 secondary ip. No drbd instances can be running on the node, while this
392 operation is taking place.
394 Example (setting the node back to online and master candidate)::
396 # gnt-node modify --offline=no --master-candidate=yes node1.example.com
402 **remove** {*nodename*}
404 Removes a node from the cluster. Instances must be removed or
405 migrated to another cluster before.
409 # gnt-node remove node5.example.com
415 **remove-tags** [--from *file*] {*nodename*} {*tag*...}
417 Remove tags from the given node. If any of the tags are not
418 existing on the node, the entire operation will abort.
420 If the ``--from`` option is given, the list of tags to be removed will
421 be extended with the contents of that file (each line becomes a tag).
422 In this case, there is not need to pass tags on the command line (if
423 you do, tags from both sources will be removed). A file name of - will
424 be interpreted as stdin.
429 | **volumes** [--no-headers] [--human-readable]
430 | [--separator=*SEPARATOR*] [{-o|--output} *FIELDS*]
433 Lists all logical volumes and their physical disks from the node(s)
436 The ``--no-headers`` option will skip the initial header line. The
437 ``--separator`` option takes an argument which denotes what will be
438 used between the output fields. Both these options are to help
441 The units used to display the numeric values in the output varies,
442 depending on the options given. By default, the values will be
443 formatted in the most appropriate unit. If the ``--separator``
444 option is given, then the values are shown in mebibytes to allow
445 parsing by scripts. In both cases, the ``--units`` option can be
446 used to enforce a given output unit.
448 The ``-o (--output)`` option takes a comma-separated list of output
449 fields. The available fields and their meaning are:
452 the node name on which the volume exists
455 the physical drive (on which the LVM physical volume lives)
458 the volume group name
461 the logical volume name
464 the logical volume size
467 The name of the instance to which this volume belongs, or (in case
468 it's an orphan volume) the character "-"
473 # gnt-node volumes node5.example.com
474 Node PhysDev VG Name Size Instance
475 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11000.meta 128 instance1.example.com
476 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11001.data 256 instance1.example.com
482 | **list-storage** [--no-headers] [--human-readable]
483 | [--separator=*SEPARATOR*] [--storage-type=*STORAGE\_TYPE*]
484 | [{-o|--output} *FIELDS*]
487 Lists the available storage units and their details for the given
490 The ``--no-headers`` option will skip the initial header line. The
491 ``--separator`` option takes an argument which denotes what will be
492 used between the output fields. Both these options are to help
495 The units used to display the numeric values in the output varies,
496 depending on the options given. By default, the values will be
497 formatted in the most appropriate unit. If the ``--separator``
498 option is given, then the values are shown in mebibytes to allow
499 parsing by scripts. In both cases, the ``--units`` option can be
500 used to enforce a given output unit.
502 The ``--storage-type`` option can be used to choose a storage unit
503 type. Possible choices are lvm-pv, lvm-vg or file.
505 The ``-o (--output)`` option takes a comma-separated list of output
506 fields. The available fields and their meaning are:
509 the node name on which the volume exists
512 the type of the storage unit (currently just what is passed in via
516 the path/identifier of the storage unit
519 total size of the unit; for the file type see a note below
522 used space in the unit; for the file type see a note below
528 whether we the unit is available for allocation (only lvm-pv can
529 change this setting, the other types always report true)
532 Note that for the "file" type, the total disk space might not equal
533 to the sum of used and free, due to the method Ganeti uses to
534 compute each of them. The total and free values are computed as the
535 total and free space values for the filesystem to which the
536 directory belongs, but the used space is computed from the used
537 space under that directory *only*, which might not be necessarily
538 the root of the filesystem, and as such there could be files
539 outside the file storage directory using disk space and causing a
540 mismatch in the values.
544 node1# gnt-node list-storage node2
545 Node Type Name Size Used Free Allocatable
546 node2 lvm-pv /dev/sda7 673.8G 1.5G 672.3G Y
547 node2 lvm-pv /dev/sdb1 698.6G 0M 698.6G Y
553 **modify-storage** [``--allocatable=yes|no``]
554 {*node*} {*storage-type*} {*volume-name*}
556 Modifies storage volumes on a node. Only LVM physical volumes can
557 be modified at the moment. They have a storage type of "lvm-pv".
561 # gnt-node modify-storage --allocatable no node5.example.com lvm-pv /dev/sdb1
567 **repair-storage** [--ignore-consistency] {*node*} {*storage-type*}
570 Repairs a storage volume on a node. Only LVM volume groups can be
571 repaired at this time. They have the storage type "lvm-vg".
573 On LVM volume groups, **repair-storage** runs "vgreduce
578 **Caution:** Running this command can lead to data loss. Use it with
581 The ``--ignore-consistency`` option will ignore any inconsistent
582 disks (on the nodes paired with this one). Use of this option is
583 most likely to lead to data-loss.
587 # gnt-node repair-storage node5.example.com lvm-vg xenvg
593 **powercycle** [``--yes``] [``--force``] {*node*}
595 This commands (tries to) forcefully reboot a node. It is a command
596 that can be used if the node environemnt is broken, such that the
597 admin can no longer login over ssh, but the Ganeti node daemon is
600 Note that this command is not guaranteed to work; it depends on the
601 hypervisor how effective is the reboot attempt. For Linux, this
602 command require that the kernel option CONFIG\_MAGIC\_SYSRQ is
605 The ``--yes`` option can be used to skip confirmation, while the
606 ``--force`` option is needed if the target node is the master
612 **power** on|off|cycle|status {*node*}
614 This commands calls out to out-of-band management to change the power
615 state of given node. With ``status`` you get the power status as reported
616 by the out-of-band managment script.
618 Note that this command will only work if the out-of-band functionality
619 is configured and enabled on the cluster. If this is not the case,
620 please use the **powercycle** command above.