Provided by: ganeti-htools_2.9.3-1_amd64 bug

NAME

       hspace - Cluster space analyzer for Ganeti

SYNOPSIS

       hspace   {backend   options...}   [algorithm   options...]  [request  options...]  [output
       options...] [-v...  | -q]

       hspace --version

       Backend options:

       { -m cluster | -L[ path ] [-X] | -t data-file | --simulate spec | -I path }

       Algorithm options:

       [ --max-cpu cpu-ratio ] [ --min-disk disk-ratio ] [ -O name... ]

       Request options:

       [--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 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).

       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  machine-readable  output  of  the  script  (all
       prefixed with HTS_):

       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, 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 the cluster.

       INI_SCORE, FIN_SCORE
              These  are the initial (current) and final cluster score (see the hbal man page for
              details about the scoring algorithm).

       INI_INST_CNT, FIN_INST_CNT
              The initial and final instance count.

       INI_MEM_FREE, FIN_MEM_FREE
              The initial  and  final  total  free  memory  in  the  cluster  (but  this  doesn't
              necessarily mean available for use).

       INI_MEM_AVAIL, FIN_MEM_AVAIL
              The  initial  and  final  total available memory for allocation in the cluster.  If
              allocating redundant instances, new instances could increase the reserved memory so
              it  doesn't  necessarily  mean  the  entirety  of  this  memory can be used for new
              instance allocations.

       INI_MEM_RESVD, FIN_MEM_RESVD
              The initial and final reserved memory (for redundancy/N+1 purposes).

       INI_MEM_INST, FIN_MEM_INST
              The initial and final memory used for instances (actual runtime used RAM).

       INI_MEM_OVERHEAD, FIN_MEM_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 memory divided by
              total memory.

       INI_DSK_FREE, INI_DSK_AVAIL, INI_DSK_RESVD, INI_DSK_INST, INI_DSK_EFF
              Initial disk stats, similar to the memory ones.

       FIN_DSK_FREE, FIN_DSK_AVAIL, FIN_DSK_RESVD, FIN_DSK_INST, FIN_DSK_EFF
              Final disk stats, similar to the memory ones.

       INI_CPU_INST, FIN_CPU_INST
              Initial and final number of virtual CPUs used by instances.

       INI_CPU_EFF, FIN_CPU_EFF
              The initial and final CPU efficiency, represented as the count of virtual  instance
              CPUs divided by the total physical CPU count.

       INI_MNODE_MEM_AVAIL, FIN_MNODE_MEM_AVAIL
              The  initial  and final maximum per-node available memory.  This is not very useful
              as a metric but can give an impression of the status of the nodes; as  an  example,
              this  value  restricts  the  maximum instance size that can be still created on the
              cluster.

       INI_MNODE_DSK_AVAIL, FIN_MNODE_DSK_AVAIL
              Like the above but for disk.

       TSPEC  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 computation
              (only for tiered allocation mode).  The NPU value is "normalized" CPU  count,  i.e.
              the  number of virtual CPUs divided by the maximum ratio of the virtual to physical
              CPUs.

       KM_POOL_CPU, KM_POOL_NPU, KM_POOL_MEM, KM_POOL_DSK
              These represents  the  total  resources  allocated  during  the  tiered  allocation
              process.  In effect, they represent how much is readily available for allocation.

       KM_UNAV_CPU, KM_POOL_NPU, KM_UNAV_MEM, KM_UNAV_DSK
              These  represents  the  resources  left  over  (either  free  as  in unallocable or
              allocable on their own) after the  tiered  allocation  has  been  completed.   They
              represent  better the actual unallocable resources, because some other resource has
              been exhausted.  For 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 hasn't been specified this will be
              -1.

       ALLOC_USAGE
              The current usage represented as initial number  of  instances  divided  per  final
              number of instances.

       ALLOC_COUNT
              The number of instances allocated (delta between FIN_INST_CNT and INI_INST_CNT).

       ALLOC_FAIL*_CNT
              For  the  last  attemp at allocations (which would have increased FIN_INST_CNT with
              one, if it had succeeded), this is the count of the  failure  reasons  per  failure
              type;  currently  defined  are FAILMEM, FAILDISK and FAILCPU which represent errors
              due to not enough memory, disk and CPUs, and FAILN1  which  represents  a  non  N+1
              compliant cluster on which we can't allocate instances at all.

       ALLOC_FAIL_REASON
              The reason for most of the failures, being one of the above FAIL* strings.

       OK     A  marker representing the successful end of the computation, and having value "1".
              If this key is not present in the output it means that the computation  failed  and
              any values present should not be relied upon.

       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:

       --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.

       -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.

       -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 being offline.
              This means a couple of things:

              · instances won't be placed on these nodes, not even temporarily; e.g.  the replace
                primary  move  is not available if the secondary node is offline, since this move
                requires a failover.

              · these nodes will not be  included  in  the  score  calculation  (except  for  the
                percentage of instances on offline nodes)

              Note  that  the algorithm will also mark as offline any nodes which are reported by
              RAPI as such, or that have "?" in file-based input in any numeric fields.

       -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, 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
              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]
              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 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.

       --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
              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
       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

       The exist status of the command will be zero, unless for some reason the algorithm fatally
       failed (e.g.  wrong node or instance data).

BUGS

       The  algorithm is highly dependent on the number of nodes; its runtime grows exponentially
       with this number, and as such is impractical for really big clusters.

       The algorithm doesn't rebalance the cluster or  try  to  get  the  optimal  fit;  it  just
       allocates  in  the  best place for the current step, without taking into consideration the
       impact on future placements.

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.