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gnt-node

NAME

gnt-node - node administration

SYNOPSIS

gnt-node command [ arguments... ]

DESCRIPTION

The gnt-node is used for managing the (physical) nodes in the ganeti system.

COMMANDS

ADD

add [ --readd ] [ -s secondary_ip ] nodename

Adds the given node to the cluster.

This command is used to join a new node to the cluster. You will have to provide the password for root of the node to be able to add the node in the cluster. The command needs to be run on the ganeti master.

Note that the command is potentially destructive, as it will forcibly join the specified host the cluster, not paying attention to its current status (it could be already in a cluster, etc.)

The -s is used in dual-home clusters and specifies the new node's IP in the secondary network. See the discussion in gnt-cluster(8) for more informations.

In case you're readding a node after hardware failure, you can use the --readd parameter.

Example:

 # gnt-node add node5.example.com
 # gnt-node add -s 192.168.44.5 node5.example.com
         
 

ADD-TAGS

add-tags [ --from file ] nodename tag ...

Add tags to the given node. If any of the tags contains invalid characters, the entire operation will abort.

If the --from option is given, the list of tags will be extended with the contents of that file (each line becomes a tag). In this case, there is not need to pass tags on the command line (if you do, both sources will be used). A file name of - will be interpreted as stdin.

EVACUATE

evacuate [ -f ] source_node destination_node

This command will change the secondary node from the source node to the destination node for all instances having the source node as secondary. It works only for instances having a remote_raid1 or drbd disk layout.

Example:

           # gnt-node evacuate node1.example.com node2.example.com
         
 

FAILOVER

failover [ -f ] [ --ignore-consistency ] node

This command will fail over all instances having the given node as primary to their secondary nodes. This works only for instances having a remote_raid1 or drbd disk layout.

Normally the failover will check the consistency of the disks before failing over the instance. If you are trying to migrate instances off a dead node, this will fail. Use the --ignore-consistency option for this purpose.

Example:

           # gnt-node failover node1.example.com
         
 

INFO

info [ node ... ]

Show detailed information about the nodes in the cluster. If you don't give any arguments, all nodes will be shows, otherwise the output will be restricted to the given names.

LIST

list [ --no-headers ] [ --separator=SEPARATOR ] [ -o [+]FIELD,... ]

Lists the nodes in the cluster. If you give the --ip-info option, the output contains just the node name, primary ip and secondary ip. In case the secondary ip is the same as the primary one, it will be listed as "-".

The --no-headers option will skip the initial header line. The --separator option takes an argument which denotes what will be used between the output fields. Both these options are to help scripting.

The -o option takes a comma-separated list of output fields. The available fields and their meaning are:

name

the node name

pinst_cnt

the number of instances having this node as primary

pinst_list

the list of instances having this node as primary, comma separated

sinst_cnt

the number of instances having this node as a secondary node

sinst_list

the list of instances having this node as a secondary node, comma separated

pip

the primary ip of this node (used for cluster communication)

sip

the secondary ip of this node (used for data replication in dual-ip clusters, see gnt-cluster(8)

dtotal

total disk space in the volume group used for instance disk allocations

dfree

available disk space in the volume group

mtotal

total memory on the physical node

mnode

the memory used by the node itself

mfree

memory available for instance allocations

bootid

the node bootid value; this is a linux specific feature that assigns a new UUID to the node at each boot and can be use to detect node reboots (by tracking changes in this value)

tags

comma-separated list of the node's tags

If the value of the option starts with the character +, the new fields will be added to the default list. This allows to quickly see the default list plus a few other fields, instead of retyping the entire list of fields.

Note that some of this fields are known from the configuration of the cluster (name, pinst, sinst, pip, sip and thus the master does not need to contact the node for this data (making the listing fast if only fields from this set are selected), whereas the other fields are "live" fields and we need to make a query to the cluster nodes.

Depending on the virtualization type and implementation details, the mtotal, mnode and mfree may have slighly varying meanings. For example, some solutions share the node memory with the pool of memory used for instances (UML), whereas others have separate memory for the node and for the instances (Xen).

LIST-TAGS

list-tags nodename

List the tags of the given node.

REMOVE

remove nodename

Removes a node from the cluster. Instances must be removed or migrated to another cluster before.

Example:

 # gnt-node remove node5.example.com
         
 

REMOVE-TAGS

remove-tags [ --from file ] nodename tag ...

Remove tags from the given node. If any of the tags are not existing on the node, the entire operation will abort.

If the --from option is given, the list of tags will be extended with the contents of that file (each line becomes a tag). In this case, there is not need to pass tags on the command line (if you do, both sources will be used). A file name of - will be interpreted as stdin.

VOLUMES

volumes [ --no-headers ] [ --human-readable ] [ --separator=SEPARATOR ] [ --output=FIELDS ]
    [ node ... ]

Lists all logical volumes and their physical disks from the node(s) provided.

The --no-headers option will skip the initial header line. The --separator option takes an argument which denotes what will be used between the output fields. Both these options are to help scripting.

The -o option takes a comma-separated list of output fields. The available fields and their meaning are:

node

the node name on which the volume exists

phys

the physical drive (on which the LVM physical volume lives)

vg

the volume group name

name

the logical volume name

size

the logical volume size

instance

The name of the instance to which this volume belongs, or (in case it's an orphan volume) the character ``-''

Example:

 # gnt-node volumes node5.example.com
 Node              PhysDev   VG    Name                                 Size Instance
 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11000.meta 128  instance1.example.com
 node1.example.com /dev/hdc1 xenvg instance1.example.com-sda_11001.data 256  instance1.example.com
         
 

REPORTING BUGS

Report bugs to 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-node(8) (node-related commands), gnt-instance(8) (instance commands), gnt-os(8) (guest OS commands). gnt-backup(8) (instance import/export commands).

Ganeti daemons: ganeti-watcher(8) (automatic instance restarter), ganeti-noded(8) (node daemon), ganeti-master(8) (the master startup script), ganeti-rapi(8) (remote API daemon).

COPYRIGHT

Copyright (C) 2006, 2007 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.