Provided by: ganeti-htools_2.9.3-1_amd64 
NAME
htools - Cluster allocation and placement tools for Ganeti
SYNOPSIS
hbal cluster balancer
hcheck cluster checker
hspace cluster capacity computation
hail IAllocator plugin
hscan saves cluster state for later reuse
hinfo cluster information printer
hroller
cluster rolling maintenance scheduler
DESCRIPTION
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 hcheck, it preforms cluster checks and optionally simulates rebalancing with all the hbal
options available.
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.
Installed as hinfo, it prints information about the current cluster state.
Installed as hroller, it helps scheduling maintenances that require node reboots on a cluster.
COMMON OPTIONS
Options behave the same in all program modes, but not all program modes support all options. Some common
options are:
-p, --print-nodes
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:
F a character denoting the status of the node, with '-' meaning an offline node, '*' meaning
N+1 failure and blank meaning a good node
Name the node name
t_mem the total node memory
n_mem the memory used by the node itself
i_mem the memory used by instances
x_mem 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
f_mem the free node memory
r_mem the reserved node memory, which is the amount of free memory needed for N+1 compliance
t_dsk total disk
f_dsk free disk
pcpu the number of physical cpus on the node
vcpu the number of virtual cpus allocated to primary instances
pcnt number of primary instances
scnt number of secondary instances
p_fmem percent of free memory
p_fdsk percent of free disk
r_cpu ratio of virtual to physical cpus
lCpu the dynamic CPU load (if the information is available)
lMem the dynamic memory load (if the information is available)
lDsk the dynamic disk load (if the information is available)
lNet the dynamic net load (if the information is available)
-t datafile, --text-data=datafile
Backend specification: the name of the file holding node and instance information (if not
collecting via RAPI or LUXI). This or one of the other backends must be selected. The option is
described in the man page htools(1).
The file should contain text data, line-based, with single empty lines separating sections. The
lines themselves are column-based, with the pipe symbol (|) acting as separator.
The first section contains group data, with the following columns:
• group name
• group uuid
• allocation policy
• tags (separated by comma)
• networks (UUID's, separated by comma)
The second sections contains node data, with the following columns:
• node name
• node total memory
• memory used by the node
• node free memory
• node total disk
• node free disk
• node physical cores
• offline/role field (Y for offline nodes, N for online non-master nodes, and M for the master
node which is always online)
• group UUID
• node spindle count
• node tags
• exclusive storage value (Y if active, N otherwise)
• node free spindles
• virtual CPUs used by the node OS
The third section contains instance data, with the fields:
• instance name
• instance memory
• instance disk size
• instance vcpus
• instance status (in Ganeti's format, e.g. running or ERROR_down)
• instance auto_balance flag (see man page gnt-instance(8))
• instance primary node
• instance secondary node(s), if any
• instance disk type (e.g. plain or drbd)
• instance tags
• spindle use back-end parameter
• actual disk spindles used by the instance (it can be - when exclusive storage is not active)
The fourth section contains the cluster tags, with one tag per line (no columns/no column
processing).
The fifth section contains the ipolicies of the cluster and the node groups, in the following
format (separated by |):
• owner (empty if cluster, group name otherwise)
• standard, min, max instance specs; min and max instance specs are separated between them by a
semicolon, and can be specified multiple times (min;max;min;max...) ; each of the specs
contains the following values separated by commas:
• memory size
• cpu count
• disk size
• disk count - NIC count
• disk templates
• vcpu ratio
• spindle ratio
-m cluster
Backend specification: collect data directly from the cluster given as an argument via RAPI. If
the argument doesn't contain a colon (:), then it is converted into a fully-built URL via
prepending https:// and appending the default RAPI port, otherwise it is considered a fully-
specified URL and used as-is.
-L [path]
Backend specification: collect data directly from the master daemon, which is to be contacted via
LUXI (an internal Ganeti protocol). An optional path argument is interpreted as the path to the
unix socket on which the master daemon listens; otherwise, the default path used by Ganeti
(configured at build time) is used.
-I|--ialloc-src path
Backend specification: load data directly from an iallocator request (as produced by Ganeti when
doing an iallocator call). The iallocator request is read from specified path.
--simulate description
Backend specification: instead of using actual data, build an empty cluster given a node
description. The description parameter must be a comma-separated list of five elements,
describing in order:
• the allocation policy for this node group (preferred, allocable or unallocable, or alternatively
the short forms p, a or u)
• the number of nodes in the cluster
• the disk size of the nodes (default in mebibytes, units can be used)
• the memory size of the nodes (default in mebibytes, units can be used)
• the cpu core count for the nodes
• the spindle count for the nodes
An example description would be preferred,20,100G,16g,4,2 describing a 20-node cluster where each
node has 100GB of disk space, 16GiB of memory, 4 CPU cores and 2 disk spindles. Note that all
nodes must have the same specs currently.
This option can be given multiple times, and each new use defines a new node group. Hence
different node groups can have different allocation policies and node count/specifications.
-v, --verbose
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.
-q, --quiet
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.
-V, --version
Just show the program version and exit.
UNITS
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.
ENVIRONMENT
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.
REPORTING BUGS
Report bugs to project website (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-extstorage-interface(7) (external storage providers).
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-
storage(8) (storage 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), hinfo(1) (cluster information
printer), mon-collector(7) (data collectors interface).
COPYRIGHT
Copyright (C) 2006, 2007, 2008, 2009, 2010, 2011, 2012 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.
Ganeti HTOOLS(1)