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HTOOLS(1) Ganeti | Version @GANETI_VERSION@

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NAME

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htools - Cluster allocation and placement tools for Ganeti

SYNOPSIS

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**hbal**

  cluster balancer

**hspace**

  cluster capacity computation

**hail**

  IAllocator plugin

**hscan**

  saves cluster state for later reuse

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 ``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.

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 two empty lines

  separating sections. The lines themselves are column-based, with the

  pipe symbol (``|``) acting as separator.

  The first section contains group data, with two columns:

  - group name

  - group uuid

  The second sections contains node data, with the following columns:

  - node name

  - node total memory

  - node free memory

  - node total disk

  - node free disk

  - node physical cores

  - offline field (as ``Y`` or ``N``)

  - group UUID

  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** (7))

  - instance primary node

  - instance secondary node(s), if any

  - instance disk type (e.g. ``plain`` or ``drbd``)

  - instance tags

  The fourth and last section contains the cluster tags, with one tag

  per line (no columns/no column processing).

-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.

--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

  An example description would be **preferred,B20,100G,16g,4**

  describing a 20-node cluster where each node has 100GB of disk

  space, 16GiB of memory and 4 CPU cores. 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.

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