htools - Cluster allocation and placement tools for Ganeti
cluster balancer
cluster capacity computation
IAllocator plugin
saves cluster state for later reuse
htools is a suite of tools designed to help with allocation/movement of instances and balancing of Ganeti clusters. htools is also the generic binary that must be symlinked or hardlinked under each tool's name in order to perform the different functions. Alternatively, the environment variable HTOOLS can be used to set the desired role.
Installed as hbal, it computes and optionally executes a suite of instance moves in order to balance the cluster.
Installed as hspace, it computes how many additional instances can be fit on a cluster, while maintaining N+1 status. It can run on models of existing clusters or of simulated clusters.
Installed as hail, it acts as an IAllocator plugin, i.e. it is used by Ganeti to compute new instance allocations and instance moves.
Installed as hscan, it scans the local or remote cluster state and saves it to files which can later be reused by the other roles.
Options behave the same in all program modes, but not all program modes support all options. Some common options are:
Prints the node status, in a format designed to allow the user to understand the node's most important parameters. If the command in question makes a cluster transition (e.g. balancing or allocation), then usually both the initial and final node status is printed.
It is possible to customise the listed information by passing a comma-separated list of field names to this option (the field list is currently undocumented), or to extend the default field list by prefixing the additional field list with a plus sign. By default, the node list will contain the following information:
a character denoting the status of the node, with '-' meaning an offline node, '*' meaning N+1 failure and blank meaning a good node
the node name
the total node memory
the memory used by the node itself
the memory used by instances
amount memory which seems to be in use but cannot be determined why or by which instance; usually this means that the hypervisor has some overhead or that there are other reporting errors
the free node memory
the reserved node memory, which is the amount of free memory needed for N+1 compliance
total disk
free disk
the number of physical cpus on the node
the number of virtual cpus allocated to primary instances
number of primary instances
number of secondary instances
percent of free memory
percent of free disk
ratio of virtual to physical cpus
the dynamic CPU load (if the information is available)
the dynamic memory load (if the information is available)
the dynamic disk load (if the information is available)
the dynamic net load (if the information is available)
Increase the output verbosity. Each usage of this option will increase the verbosity (currently more than 2 doesn't make sense) from the default of one.
Decrease the output verbosity. Each usage of this option will decrease the verbosity (less than zero doesn't make sense) from the default of one.
Just show the program version and exit.
Some options accept not simply numerical values, but numerical values together with a unit. By default, such unit-accepting options use mebibytes. Using the lower-case letters of m, g and t (or their longer equivalents of mib, gib, tib, for which case doesn't matter) explicit binary units can be selected. Units in the SI system can be selected using the upper-case letters of M, G and T (or their longer equivalents of MB, GB, TB, for which case doesn't matter).
More details about the difference between the SI and binary systems can be read in the units(7) man page.
The environment variable HTOOLS can be used instead of renaming/symlinking the programs; simply set it to the desired role and then the name of the program is no longer used.
Report bugs to project website or contact the developers using the Ganeti mailing list.
Ganeti overview and specifications: ganeti(7) (general overview), ganeti-os-interface(7) (guest OS definitions).
Ganeti commands: gnt-cluster(8) (cluster-wide commands), gnt-job(8) (job-related commands), gnt-node(8) (node-related commands), gnt-instance(8) (instance commands), gnt-os(8) (guest OS commands), gnt-group(8) (node group commands), gnt-backup(8) (instance import/export commands), gnt-debug(8) (debug commands).
Ganeti daemons: ganeti-watcher(8) (automatic instance restarter), ganeti-cleaner(8) (job queue cleaner), ganeti-noded(8) (node daemon), ganeti-masterd(8) (master daemon), ganeti-rapi(8) (remote API daemon).
Ganeti htools: htools(1) (generic binary), hbal(1) (cluster balancer), hspace(1) (capacity calculation), hail(1) (IAllocator plugin), hscan(1) (data gatherer from remote clusters).
Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011 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.