-HSPACE(1) htools | Ganeti H-tools
-=================================
+HSPACE(1) Ganeti | Version @GANETI_VERSION@
+===========================================
NAME
----
--------
**hspace** {backend options...} [algorithm options...] [request options...]
-[ -p [*fields*] ] [-v... | -q]
+[output options...] [-v... | -q]
-**hspace** --version
+**hspace** \--version
Backend options:
{ **-m** *cluster* | **-L[** *path* **] [-X]** | **-t** *data-file* |
-**--simulate** *spec* }
+**\--simulate** *spec* | **-I** *path* }
Algorithm options:
-**[ --max-cpu *cpu-ratio* ]**
-**[ --min-disk *disk-ratio* ]**
+**[ \--max-cpu *cpu-ratio* ]**
+**[ \--min-disk *disk-ratio* ]**
**[ -O *name...* ]**
Request options:
-**[--memory** *mem* **]**
-**[--disk** *disk* **]**
-**[--req-nodes** *req-nodes* **]**
-**[--vcpus** *vcpus* **]**
-**[--tiered-alloc** *spec* **]**
+**[\--disk-template** *template* **]**
+
+**[\--standard-alloc** *disk,ram,cpu* **]**
+
+**[\--tiered-alloc** *disk,ram,cpu* **]**
+
+Output options:
+
+**[\--machine-readable**[=*CHOICE*] **]**
+**[-p**[*fields*]**]**
DESCRIPTION
-----------
-
hspace computes how many additional instances can be fit on a cluster,
while maintaining N+1 status.
The program will try to place instances, all of the same size, on the
cluster, until the point where we don't have any N+1 possible
allocation. It uses the exact same allocation algorithm as the hail
-iallocator plugin.
+iallocator plugin in *allocate* mode.
+
+The output of the program is designed either for human consumption (the
+default) or, when enabled with the ``--machine-readable`` option
+(described further below), for machine consumption. In the latter case,
+it is intended to interpreted as a shell fragment (or parsed as a
+*key=value* file). Options which extend the output (e.g. -p, -v) will
+output the additional information on stderr (such that the stdout is
+still parseable).
-The output of the program is designed to interpreted as a shell
-fragment (or parsed as a *key=value* file). Options which extend the
-output (e.g. -p, -v) will output the additional information on stderr
-(such that the stdout is still parseable).
+By default, the instance specifications will be read from the cluster;
+the options ``--standard-alloc`` and ``--tiered-alloc`` can be used to
+override them.
-The following keys are available in the output of the script (all
-prefixed with *HTS_*):
+The following keys are available in the machine-readable output of the
+script (all prefixed with *HTS_*):
-SPEC_MEM, SPEC_DSK, SPEC_CPU, SPEC_RQN
+SPEC_MEM, SPEC_DSK, SPEC_CPU, SPEC_RQN, SPEC_DISK_TEMPLATE
These represent the specifications of the instance model used for
- allocation (the memory, disk, cpu, requested nodes).
+ allocation (the memory, disk, cpu, requested nodes, disk template).
+
+TSPEC_INI_MEM, TSPEC_INI_DSK, TSPEC_INI_CPU, ...
+ Only defined when the tiered mode allocation is enabled, these are
+ similar to the above specifications but show the initial starting spec
+ for tiered allocation.
CLUSTER_MEM, CLUSTER_DSK, CLUSTER_CPU, CLUSTER_NODES
These represent the total memory, disk, CPU count and total nodes in
RAM).
INI_MEM_OVERHEAD, FIN_MEM_OVERHEAD
- The initial and final memory overhead--memory used for the node
- itself and unacounted memory (e.g. due to hypervisor overhead).
+ The initial and final memory overhead, i.e. memory used for the node
+ itself and unaccounted memory (e.g. due to hypervisor overhead).
INI_MEM_EFF, HTS_INI_MEM_EFF
The initial and final memory efficiency, represented as instance
Like the above but for disk.
TSPEC
- If the tiered allocation mode has been enabled, this parameter holds
- the pairs of specifications and counts of instances that can be
- created in this mode. The value of the key is a space-separated list
- of values; each value is of the form *memory,disk,vcpu=count* where
- the memory, disk and vcpu are the values for the current spec, and
- count is how many instances of this spec can be created. A complete
- value for this variable could be: **4096,102400,2=225
- 2560,102400,2=20 512,102400,2=21**.
+ This parameter holds the pairs of specifications and counts of
+ instances that can be created in the *tiered allocation* mode. The
+ value of the key is a space-separated list of values; each value is of
+ the form *memory,disk,vcpu=count* where the memory, disk and vcpu are
+ the values for the current spec, and count is how many instances of
+ this spec can be created. A complete value for this variable could be:
+ **4096,102400,2=225 2560,102400,2=20 512,102400,2=21**.
KM_USED_CPU, KM_USED_NPU, KM_USED_MEM, KM_USED_DSK
These represents the metrics of used resources at the start of the
example, the cluster might still have 100GiB disk free, but with no
memory left for instances, we cannot allocate another instance, so
in effect the disk space is unallocable. Note that the CPUs here
- represent instance virtual CPUs, and in case the *--max-cpu* option
+ represent instance virtual CPUs, and in case the *\--max-cpu* option
hasn't been specified this will be -1.
ALLOC_USAGE
that the computation failed and any values present should not be
relied upon.
-If the tiered allocation mode is enabled, then many of the INI_/FIN_
-metrics will be also displayed with a TRL_ prefix, and denote the
-cluster status at the end of the tiered allocation run.
+Many of the INI_/FIN_ metrics will be also displayed with a TRL_ prefix,
+and denote the cluster status at the end of the tiered allocation run.
+
+The human output format should be self-explanatory, so it is not
+described further.
OPTIONS
-------
The options that can be passed to the program are as follows:
---memory *mem*
- The memory size of the instances to be placed (defaults to 4GiB).
-
---disk *disk*
- The disk size of the instances to be placed (defaults to 100GiB).
-
---req-nodes *num-nodes*
- The number of nodes for the instances; the default of two means
- mirrored instances, while passing one means plain type instances.
-
---vcpus *vcpus*
- The number of VCPUs of the instances to be placed (defaults to 1).
-
---max-cpu=*cpu-ratio*
- The maximum virtual to physical cpu ratio, as a floating point
- number between zero and one. For example, specifying *cpu-ratio* as
- **2.5** means that, for a 4-cpu machine, a maximum of 10 virtual
- cpus should be allowed to be in use for primary instances. A value
- of one doesn't make sense though, as that means no disk space can be
- used on it.
-
---min-disk=*disk-ratio*
+\--disk-template *template*
+ Overrides the disk template for the instance read from the cluster;
+ one of the Ganeti disk templates (e.g. plain, drbd, so on) should be
+ passed in.
+
+\--spindle-use *spindles*
+ Override the spindle use for the instance read from the cluster. The
+ value can be 0 (for example for instances that use very low I/O), but not
+ negative. For shared storage the value is ignored.
+
+\--max-cpu=*cpu-ratio*
+ The maximum virtual to physical cpu ratio, as a floating point number
+ greater than or equal to one. For example, specifying *cpu-ratio* as
+ **2.5** means that, for a 4-cpu machine, a maximum of 10 virtual cpus
+ should be allowed to be in use for primary instances. A value of
+ exactly one means there will be no over-subscription of CPU (except
+ for the CPU time used by the node itself), and values below one do not
+ make sense, as that means other resources (e.g. disk) won't be fully
+ utilised due to CPU restrictions.
+
+\--min-disk=*disk-ratio*
The minimum amount of free disk space remaining, as a floating point
number. For example, specifying *disk-ratio* as **0.25** means that
at least one quarter of disk space should be left free on nodes.
--p, --print-nodes
- Prints the before and after node status, in a format designed to
- allow the user to understand the node's most important parameters.
-
- 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
+-l *rounds*, \--max-length=*rounds*
+ Restrict the number of instance allocations to this length. This is
+ not very useful in practice, but can be used for testing hspace
+ itself, or to limit the runtime for very big clusters.
- 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)
+-p, \--print-nodes
+ Prints the before and after node status, in a format designed to allow
+ the user to understand the node's most important parameters. See the
+ man page **htools**(1) for more details about this option.
-O *name*
This option (which can be given multiple times) will mark nodes as
are reported by RAPI as such, or that have "?" in file-based input
in any numeric fields.
--t *datafile*, --text-data=*datafile*
- 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.
-
--S *filename*, --save-cluster=*filename*
+-S *filename*, \--save-cluster=*filename*
If given, the state of the cluster at the end of the allocation is
saved to a file named *filename.alloc*, and if tiered allocation is
enabled, the state after tiered allocation will be saved to
*filename.tiered*. This allows re-feeding the cluster state to
either hspace itself (with different parameters) or for example
- hbal.
+ hbal, via the ``-t`` option.
+
+-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).
-m *cluster*
- 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's considered a
- fully-specified URL and is used as-is.
+ Backend specification: collect data directly from the *cluster* given
+ as an argument via RAPI. The option is described in the man page
+ **htools**(1).
-L [*path*]
- Collect data directly from the master daemon, which is to be
- contacted via the 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 when installed with *--localstatedir=/var* is used.
-
---simulate *description*
- Instead of using actual data, build an empty cluster given a node
- description. The *description* parameter must be a comma-separated
- list of four elements, describing in order:
-
- - the number of nodes in the cluster
- - the disk size of the nodes, in mebibytes
- - the memory size of the nodes, in mebibytes
- - the cpu core count for the nodes
-
- An example description would be **B20,102400,16384,4** describing a
- 20-node cluster where each node has 100GiB of disk space, 16GiB of
- memory and 4 CPU cores. Note that all nodes must have the same specs
- currently.
-
---tiered-alloc *spec*
- Besides the standard, fixed-size allocation, also do a tiered
- allocation scheme where the algorithm starts from the given
- specification and allocates until there is no more space; then it
- decreases the specification and tries the allocation again. The
- decrease is done on the matric that last failed during
- allocation. The specification given is similar to the *--simulate*
- option and it holds:
-
- - the disk size of the instance
- - the memory size of the instance
+ Backend specification: collect data directly from the master daemon,
+ which is to be contacted via LUXI (an internal Ganeti protocol). The
+ option is described in the man page **htools**(1).
+
+\--simulate *description*
+ Backend specification: similar to the **-t** option, this allows
+ overriding the cluster data with a simulated cluster. For details
+ about the description, see the man page **htools**(1).
+
+\--standard-alloc *disk,ram,cpu*
+ This option overrides the instance size read from the cluster for the
+ *standard* allocation mode, where we simply allocate instances of the
+ same, fixed size until the cluster runs out of space.
+
+ The specification given is similar to the *\--simulate* option and it
+ holds:
+
+ - the disk size of the instance (units can be used)
+ - the memory size of the instance (units can be used)
- the vcpu count for the insance
- An example description would be *10240,8192,2* describing an initial
- starting specification of 10GiB of disk space, 4GiB of memory and 2
- VCPUs.
+ An example description would be *100G,4g,2* describing an instance
+ specification of 100GB of disk space, 4GiB of memory and 2 VCPUs.
+
+\--tiered-alloc *disk,ram,cpu*
+ This option overrides the instance size for the *tiered* allocation
+ mode. In this mode, the algorithm starts from the given specification
+ and allocates until there is no more space; then it decreases the
+ specification and tries the allocation again. The decrease is done on
+ the metric that last failed during allocation. The argument should
+ have the same format as for ``--standard-alloc``.
Also note that the normal allocation and the tiered allocation are
independent, and both start from the initial cluster state; as such,
the instance count for these two modes are not related one to
another.
--v, --verbose
+\--machine-readable[=*choice*]
+ By default, the output of the program is in "human-readable" format,
+ i.e. text descriptions. By passing this flag you can either enable
+ (``--machine-readable`` or ``--machine-readable=yes``) or explicitly
+ disable (``--machine-readable=no``) the machine readable format
+ described above.
+
+-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
+-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
+-V, \--version
Just show the program version and exit.
+UNITS
+~~~~~
+
+By default, all 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.
+
EXIT STATUS
-----------
fit; it just allocates in the best place for the current step, without
taking into consideration the impact on future placements.
-ENVIRONMENT
------------
-
-If the variables **HTOOLS_NODES** and **HTOOLS_INSTANCES** are present
-in the environment, they will override the default names for the nodes
-and instances files. These will have of course no effect when the RAPI
-or Luxi backends are used.
-
-SEE ALSO
---------
-
-**hbal**(1), **hscan**(1), **hail**(1), **ganeti**(7),
-**gnt-instance**(8), **gnt-node**(8)
-
-COPYRIGHT
----------
-
-Copyright (C) 2009, 2010 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.
+.. vim: set textwidth=72 :
+.. Local Variables:
+.. mode: rst
+.. fill-column: 72
+.. End:
projects / ganeti-local / blobdiff