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volassist(8)							  volassist(8)

NAME
       volassist  -  Create, mirror, back up, grow, shrink, move, add logs to,
       and support online backup of LSM volumes

SYNOPSIS
       /sbin/volassist help [help_topic | showattrs | space]

       /sbin/volassist [-vf] [-g diskgroup] [-U usetype] [-o useopt] [-b]  [-c
       nocluster] [-d defaults] [-n] make volume length [attribute...]

       /sbin/volassist [-vf] [-g diskgroup] [-U usetype] [-o useopt] [-n] [-b]
       mirror volume [attribute...]

       /sbin/volassist [-vf] [-g  diskgroup]  [-U  usetype]  [-o  useopt]  [-c
       nocluster] [-n] addlog volume [attribute...]

       /sbin/volassist	[-vf]  [-g  diskgroup]	[-U  usetype]  [-o useopt] [-c
       nocluster] [-n] addfpa volume [attribute...]

       /sbin/volassist [-vf] [-g diskgroup] [-U usetype] [-o useopt] [-b] [-n]
       move volume !storage_spec... [attribute...]

       /sbin/volassist [-vf] [-g diskgroup] [-U usetype] [-o useopt] [-n] [-b]
       growto volume new_length [attribute...]

       /sbin/volassist [-vf] [-g diskgroup] [-U usetype] [-o useopt] [-n] [-b]
       growby volume length_change [attribute...]

       /sbin/volassist	[-vf]  [-g  diskgroup]	[-U  usetype] [-o useopt] [-n]
       shrinkto volume new_length

       /sbin/volassist [-vf] [-g diskgroup]  [-U  usetype]  [-o	 useopt]  [-n]
       shrinkby volume length_change

       /sbin/volassist	[-vf] [-g diskgroup] [-U usetype] [-o useopt] snapfast
       primary_volume secondary_volume

       /sbin/volassist [-vf] [-g diskgroup] [-U usetype] [-o useopt]  snapback
       secondary_volume primary_volume

       /sbin/volassist [-vf] [-g diskgroup] [-U usetype] [-o useopt] [-n] [-b]
       snapstart volume [attribute...]

       /sbin/volassist [-vf] [-g diskgroup]  [-U  usetype]  [-o	 useopt]  [-n]
       snapshot volume new_volume

       /sbin/volassist	[-v]  [-g diskgroup] [-U usetype] [-o useopt] snapwait
       volume

       /sbin/volassist [-g diskgroup] [-U usetype] [-o	useopt]	 [-p]  maxsize
       [attribute...]

       /sbin/volassist	[-g  diskgroup]	 [-U usetype] [-o useopt] [-p] maxgrow
       volume [attribute...]

OPTIONS
       Specifies the disk group for the operation, either by disk group ID  or
       by  disk	 group name. By default, the disk group is chosen based on the
       storage specification attributes (if any) for the volassist make opera‐
       tion, or based on the volume operands for all other operations.	Limits
       the operation to apply to this usage type. Attempts to  affect  volumes
       with  a different usage type will fail. For a volassist make operation,
       this indicates the usage type to use for the created volume. Otherwise,
       the  default  is used and is determined by the existence of an entry in
       the /etc/default/volassist file or is set  to  the  fsgen  usage	 type.
       Passes  in  usage-type-specific options to the operation. A certain set
       of operations are expected  to  be  implemented	by  all	 usage	types:
       Reduces	the  system  performance  impact of copy operations.  Copy and
       plex consistency recovery operations are usually a set of short	opera‐
       tions on small regions of the volume (normally from 16 kilobytes to 128
       kilobytes).  This option inserts a delay between the recovery  of  each
       such region. A specific delay can be specified with iodelay as a number
       of milliseconds, or a default is chosen	(normally  250	milliseconds).
       Performs copy and recovery operations in regions with the length speci‐
       fied by size, which is a standard Logical Storage Manager length number
       (see  volintro(8)).  Specifying	a  larger  number typically causes the
       operation to complete sooner, but with greater  impact  on  other  pro‐
       cesses  using the volume.  The default I/O size is typically between 32
       and 256 kilobytes.  Performs extended  operations  in  the  background.
       This  applies  to  plex	consistency  recovery operations for volassist
       make, growto, and growby.  This flag also applies to plex attach opera‐
       tions  started  by  volassist mirror and volassist snapstart but not to
       the snapback operation.	Specifies a file containing defaults for vari‐
       ous  attributes	related	 to  volume  creation  and  space  allocation.
       Attribute values that are passed in through this file will override any
       values  specified  in the system defaults file, /etc/default/volassist.
       Forces certain operations that are disallowed  by  default  to  prevent
       their  incorrect	 use. The force option is required to: Shrink a volume
       (with shrinkto or shrinkby).  Create a RAID 5 volume  using  the	 nolog
       attribute.   Use	 FPA  on a volume that will be left unmirrored (having
       fewer than two complete, enabled, read-write plexes) after an FPA oper‐
       ation.	Return	a migrant plex to a primary volume when the FPA log is
       disabled on either the primary or secondary  volume.   Grow  a  primary
       volume  that  is actively FPA logging (while a migrant plex is attached
       to a secondary volume). Use this option with caution,  as  it  disables
       the FPA log plex on the primary volume, resulting in a full plex resyn‐
       chronization when the migrant plex is reattached to the primary volume.
       Specifies  a  log size (for a DRL or FPA log plex) for mirrored volumes
       of 2 blocks per GB of volume size, instead of 65	 blocks	 per  GB  (the
       default).  Applicable  only on a standalone system. This option is dis‐
       abled in a TruCluster  Server  environment.  If	the  volume  is	 later
       imported	 on a cluster, logging is disabled for the volume.  Limits the
       output of the maxsize and maxgrow operations to a  numeric  value  only
       (no  text).  This option is mainly for use in scripts.  Prevents volas‐
       sist from using the defaults specified in  the  system  defaults	 file,
       /etc/default/volassist, when creating volumes.  Specifies verbose mode,
       printing a trace of other utilities that are called.

DESCRIPTION
       The volassist command is an LSM command that finds space for  and  cre‐
       ates  volumes,  adds  mirrors and logs to existing volumes, extends and
       shrinks existing volumes, provides for the migration of data from spec‐
       ified  disks, and provides facilities for the online backup of existing
       volumes.

       volassist operations are applied to only one  disk  group  at  a	 time,
       which by default is the rootdg disk group.  Use the -g diskgroup option
       to specify a disk group. You can specify a default disk	group  in  the
       /etc/default/volassist file.

       Many  volassist	operations  use	 attributes to specify how volumes are
       laid out and on which disks, among other things. Attributes are of  two
       basic types: storage specifications and attribute settings.

       Storage	specification  attributes  consist of a simple disk media name
       (for example, disk01) or disk access name (for example, dsk5a). If  the
       storage specification attribute is prefixed with !  (or, \!  from csh),
       the specified disk or partition is excluded  from  the  operation.  For
       example,	 the  following	 command  creates  a 1000MB volume on any non‐
       volatile, unreserved disk other than disk03:

       /sbin/volassist make vol1 1000m !disk03

       Other attributes are of the form attrname=value. These attributes spec‐
       ify  the	 type  of a volume (mirrored, RAID 5, striped, logged), layout
       policies (contiguous, spanning), mirroring requirements and  more.  See
       KEYWORDS for a complete list of attribute specifications.

KEYWORDS
       volassist keywords are: Displays a list of help topic keywords that can
       be combined with volassist help to display detailed information on com‐
       mand usage, options, and attributes.

	      The volassist help showattrs keyword combination displays a list
	      of current attribute settings.

	      The volassist help space keyword	combination  displays  current
	      disk  allocation	information.  Creates a volume with the speci‐
	      fied name and the specified length. The length is specified as a
	      standard	Logical	 Storage  Manager  length  (see	 volintro(8)).
	      Attributes can be specified to indicate various desired  proper‐
	      ties and storage locations for the created volume.

	      By  default,  a DRL is created when you create a mirrored volume
	      and a RAID 5 log is created when you create a RAID 5 volume. Use
	      the  layout=mirror,nolog option to create a mirrored volume with
	      DRL disabled. See EXAMPLES.  Creates a  new  mirror  (plex)  and
	      attaches	it to a concatenated or striped volume. This operation
	      is allowed only if  the  volume  is  enabled.  You  can  specify
	      attributes  to indicate desired properties and storage locations
	      for the mirror. A mirrored volume has at least two data  plexes.
	      When  mirroring a previously unmirrored volume, LSM does not add
	      a DRL. Use volassist addlog to add a log.	 Adds a log to a  RAID
	      5	 volume or to a mirrored volume whose logging type is DRL (the
	      default). Adding a log to a mirrored volume involves creating  a
	      single  log  subdisk and a new plex to contain that subdisk. The
	      new plex is then attached to the volume. Adding a log to a  RAID
	      5	 volume involves creating a new plex that attaches to the vol‐
	      ume as a log plex. The addlog command automatically creates  and
	      attaches these objects.

					    Note

	      Adding  a	 DRL  log to the root volume (rootvol) on a standalone
	      system, the cluster root domain volume (clurootvol) in  a	 clus‐
	      ter, or any swap volume is unsupported.

	      When  adding  the	 first log to a mirrored or RAID 5 volume, you
	      can use the loglen=length attribute to specify the length of the
	      log.  Otherwise, LSM uses the default log size, which LSM calcu‐
	      lates based on the volume size and layout type.

	      Subsequent logs added to the volume use the loglen attribute  of
	      the  first  log.	You  can  specify other attributes to indicate
	      desired properties  for  the  new	 allocations.  Mirroring  con‐
	      straints do not apply to logs, though storage constraints can be
	      specified that constrain the logs to disks already used  by  the
	      volume.  However, for better performance, the DRL should not use
	      disks that are currently used for volume data. See EXAMPLES.

	      The minimum DRL length is 65 blocks for a	 cluster  environment,
	      and 2 blocks for a non-cluster environment. By default, LSM con‐
	      figures a larger log subdisk  for	 the  DRL  than	 needed.  This
	      allows  you to use the volume if the system becomes a Tru64 UNIX
	      cluster member. If you configure a DRL size less than 65	blocks
	      for  a  non-cluster environment, DRL is disabled for that volume
	      if you later migrate it to a cluster environment.	  Creates  and
	      attaches	an FPA log to the specified volume.  If the volume has
	      a DRL log, the FPA log length will be the same as	 the  DRL.  If
	      not, when adding the first FPA log to a mirrored volume, you can
	      specify the length of the log with the loglen=length  attribute,
	      the  number  of  FPA  logs with the nfpalog=count attribute, and
	      which disks it can or cannot use. To exclude storage, use the  !
	      prefix (or \!  in csh).

	      If  the  volume  already has one FPA log you can add another for
	      redundancy, just as for DRL logs, except while a migrant plex is
	      detached from the volume (attached to a secondary volume).

	      Adding  an FPA log is supported for the root volume (rootvol) on
	      a standalone system and the cluster  root	 domain	 volume	 (clu‐
	      rootvol) in a cluster, but not for swap volumes.	Moves subdisks
	      within the named volume off the excluded	storage	 specified  on
	      the command line. Excluded storage is specified with a prefix of
	      !	 (or, \!  from csh). The move operation requires that at least
	      one  excluded storage specification be given. See Storage Speci‐
	      fications for a description of how to specify the excluded stor‐
	      age.

	      You can specify a target device for the move or allow LSM to use
	      any available space in the disk group. If you specify  a	target
	      device  it must be large enough to support the move (equal to or
	      larger than the excluded storage) or the move will fail.

	      If the volume is enabled, subdisks within detached  or  disabled
	      plexes  (or detached log or RAID 5 subdisks) will be moved with‐
	      out recovery of data.  If the volume is not enabled,  stale  log
	      or  RAID 5 subdisks, or subdisks within STALE or OFFLINE plexes,
	      will be moved without recovery.  If  there  are  other  subdisks
	      within a non-enabled volume that require moving, the move opera‐
	      tion will fail.

	      For enabled subdisks in enabled plexes within an enabled volume,
	      the  data	 within	 subdisks  will	 be moved to the new location,
	      without loss of availability  (or	 redundancy)  of  the  volume.
	      Increases the length of the named volume to the length specified
	      by  new_length  (growto),	 or  by	 the   length	specified   by
	      length_change  (growby).	The  new length or change in length is
	      specified as a standard  Logical	Storage	 Manager  length  (see
	      volintro(8)).  The  growto  operation fails if the new length is
	      not greater than the current volume length.

	      The length of the volume is increased by extending existing sub‐
	      disks  in the volume, or by adding and associating new subdisks.
	      Plexes that are not fully populated already (that is,  that  are
	      sparse)  are  left  unchanged.  Log-only	plexes	are  also left
	      unchanged.

	      Attributes can be specified to indicate various desired  proper‐
	      ties  for	 the  new  allocations. Any mirroring constraints will
	      still apply between all extensions to the existing  mirrors  and
	      the other mirrors.

	      Growing  a volume requires that the volume be enabled. Growing a
	      volume that is actively FPA logging (a migrant plex is detached)
	      requires the -f option.

	      The  volassist  growto/growby  operations	 have no effect on any
	      file systems that reside on the volume (or other	users  of  the
	      volume). It is expected that any necessary application notifica‐
	      tions will be made after the grow operation  completes  success‐
	      fully.   Decreases  the length of the named volume to the length
	      specified by new_length (shrinkto), or by the  length  specified
	      by length_change (shrinkby).  The new length or change in length
	      is specified as a standard Logical Storage Manager  length  (see
	      volintro(8)).  The shrinkto operation fails if the new length is
	      not less than the current volume length.

	      The length of a volume is decreased by removing  and  shortening
	      subdisks	to leave each plex with the desired volume length. The
	      freed space can then be allocated for use by other volumes. Log-
	      only plexes are left unchanged.

	      The volassist shrinkto/shrinkby operations have no effect on any
	      file systems that reside on the volume (or other	users  of  the
	      volume). It is expected that any necessary application notifica‐
	      tions will be made before the shrink operation is initiated.

					   Notes

	      File systems such as AdvFS and UFS cannot currently take	advan‐
	      tage of a shrunk volume.

	      These  operations are currently disallowed by default to prevent
	      their incorrect use with an existing AdvFS or UFS	 file  system.
	      To  override  this  default  behavior  and  force	 the volume to
	      shrink, you must use the -f force option.	 Creates and  adds  an
	      FPA  log	plex to the specified volume (if none exists), adds an
	      FPA logging subdisk to an active data  plex,  synchronizes  both
	      FPA logs, detaches the plex with the FPA subdisk (now considered
	      a migrant plex) from the volume (now considered the primary vol‐
	      ume),  creates  a	 secondary  volume with the specified name and
	      attaches the migrant plex to the secondary volume.

	      Only one snapfast operation at a time is permitted on a  volume.
	      After a migrant plex is returned to the primary volume and fully
	      resynchronized (with the	snapback  command),  another  snapfast
	      operation can be performed.

	      There  is	 no  limit  to how long a migrant plex can be detached
	      from its primary volume; however, the benefit of using FPA might
	      be  reduced  as  more writes occur to either volume.  Detaches a
	      migrant plex from the specified secondary volume, reattaches the
	      migrant  plex to the primary volume, merges the FPA logs for the
	      primary volume and the migrant plex, and manages	atomic	copies
	      to resynchronize the migrant plex to the primary volume. The FPA
	      subdisk attached to the migrant plex is disabled and  destroyed,
	      and  the	disk  space it used is returned to the free space pool
	      until the next snapfast operation.

	      If the secondary volume had only one plex	 (the  migrant	plex),
	      the  secondary  volume is destroyed.  Creates a temporary mirror
	      and attaches it to the named volume.  When the attach completes,
	      the  mirror  will be considered a candidate for selection by the
	      snapshot operation. The snapshot operation takes	one  of	 these
	      attached	temporary  mirrors  and	 creates a new volume with the
	      temporary mirror as its one plex. You can specify attributes  to
	      indicate desired properties of the snapshot mirror.

	      Some  usage types will attempt to synchronize any in-memory data
	      associated with the volume (such as unwritten file system	 modi‐
	      fications)  when	the  snapshot  operation is done. For UFS, the
	      synchronization operation consists of a call to  sync(8),	 which
	      will  make the snapshot a better image, but which may leave some
	      inconsistencies between in-memory file system data and the  data
	      residing on the backup image.

	      To ensure data synchronization with AdvFS file systems, you must
	      unmount the file systems before doing  the  snapshot  operation.
	      If  a snapstart mirror attach is done as a background task (such
	      as using the -b option), it may be convenient  to	 wait  for  an
	      attached	mirror	to  become  available.	The snapwait operation
	      waits for such an attach to complete on the named volume. When a
	      snapshot	attach	has  completed, the operation exits. Primarily
	      useful in scripts, following  a  snapstart  operation.   Returns
	      information  on the maximum volume size that can be created from
	      the available space, given a particular set of attributes.   See
	      EXAMPLES.	  When	used  with  the	 -p  option, maxsize returns a
	      numeric value only.  Returns information on the  maximum	amount
	      of  space	 by which the specified volume can be extended and the
	      maximum size to which it can grow, given the available space and
	      a	 particular  set  of attributes. When used with the -p option,
	      maxgrow returns a numeric value  only,  indicating  the  maximum
	      size to which the volume can grow.

ATTRIBUTES
       You  can	 specify  values  for various attributes with arguments of the
       form attribute=value, or as a list of (possibly negated) storage speci‐
       fications.   Attributes	can also be passed in through a defaults file.
       Default attribute values can be stored in the file  /etc/default/volas‐
       sist.  In a defaults file, attributes are separated by spaces or are on
       separate lines. Blank lines in a defaults file are  ignored,  and  com‐
       ments can be included with the standard # convention.

       Attributes  are	applied	 according  to	the  order  in	which they are
       scanned.	 If conflicting attributes are specified, the last one	speci‐
       fied  takes precedence and is used. In general, attributes are applied,
       in decreasing priority, from: The command line.	The specified defaults
       file,  as  supplied  with  the  -d  command  line argument.  The system
       defaults file, as specified in /etc/default/volassist.

       Attributes from all sources have the same form. However, in some cases,
       command-line attributes change default behaviors in ways that defaults-
       file supplied attributes do not. In particular, references to mirroring
       (such  as  specifying  a mirror count) or logging (such as specifying a
       log count or length) on the command line will cause mirroring  or  log‐
       ging  to	 happen	 by  default.	If  such attributes are specified in a
       defaults file, they just indicate the attributes that would be used  if
       mirroring or logging were enabled.

   Storage Specifications
       Storage specification attributes have one of the following forms: Spec‐
       ifies (or excludes) the given disk. The diskname parameter refers to  a
       disk media record name in a Logical Storage Manager disk group.	Speci‐
       fies (or excludes) a specific Logical  Storage  Manager	disk  by  disk
       access  record  name. An example of a disk access record name is dsk5a,
       which indicates a special Logical Storage Manager disk defined on  par‐
       tition a of disk dsk5.  Specifies (or excludes) all LSM disks on a spe‐
       cific physical disk. The physical disk is specified in the  form	 dsk#,
       which  indicates the disk number. Normally, only one LSM disk device is
       created for each physical disk. However, the voldisk  define  operation
       (see  voldisk(8))  can be used to create additional LSM disk devices on
       selected partitions.  Specifies (or excludes) a Logical Storage Manager
       disk by disk media record name, in the disk group of the volume.

   Other Attributes
       Other attributes are of the form attribute=value. The attribute name in
       an attribute value pair will never contain a colon, so it  is  possible
       to  specify a disk that has an equal sign in its name using the storage
       specification dm:disk01=a. Without the dm: prefix, disk01=a would yield
       an error indicating an unrecognized attribute.

       Defined	attributes  (and  common  aliases) are: This is provided as an
       alternate syntax for specifying storage as  single  attributes.	It  is
       useful  in  a  defaults file, so that all attributes (including storage
       specifications) will be in the attribute=value format.  Any  number  of
       storage specifications can be specified, separated by commas. More than
       one alloc attribute can be specified, in which case they are  logically
       concatenated to form one longer list.  Specifies a comment to give to a
       volume when it is created.  This comment can be displayed with volprint
       -l,  and	 can  be  changed,  at	a  later  time, with voledit set. This
       attribute is used only with the make  operation.	  Specifies  the  disk
       group  for  an  operation.   If a disk group is specified in a defaults
       file, it just specifies the default disk group  to  use	for  the  make
       operation, if no other means of determining the disk group can be used.
       If specified as a command line attribute, it has	 the  same  effect  as
       specifying  a disk group with the -g option (the operation is forced to
       apply to the given disk group).	Sets the owning group for a  new  vol‐
       ume.  The  group	 can  be  specified numerically or with a system group
       name. This attribute is used only with the make operation. By  default,
       volumes are created in group 0.	Specifies the means for initializing a
       new volume. The default method (which can be selected  explicitly  with
       init=default)  is  to  call  volume  start  to do a usage-type-specific
       default initialization operation.

	      Some useful  initialization  states  for	new  volumes  include:
	      init=none,  which	 leaves	 the volume uninitialized.  init=zero,
	      which clears (zeroes out)	 the  volume  before  it  is  enabled.
	      init=active,  which indicates that the plexes of a mirrored vol‐
	      ume do not need an initial synchronization. This can  save  time
	      prior  to creating a file system when the contents of the volume
	      are guaranteed to be written before  being  read.	  Specifies  a
	      volume  or  plex	layout	type  (concatenated, RAID 5, mirrored,
	      unmirrored, striped, and others) and turns on or off  some  fea‐
	      tures  (such as logging). By default, LSM creates an unmirrored,
	      non-striped (concatenated) volume with no log.

	      See the next section (Layout  Specifications)  for  the  defined
	      layout_spec  values.   Specifies	a  log length to use for dirty
	      region log subdisks for mirrored volumes, FPA log plexes or sub‐
	      disks  for  the  Fast  Plex  Attach  feature,  or for RAID 5 log
	      plexes. If a log length is specified on the command  line,  log‐
	      ging  is	enabled	 by default.  Specifies the logging type for a
	      mirrored volume. Dirty  region  logging  (the  default)  can  be
	      selected	with  either logtype=drl or logtype=region. To disable
	      logging, enter: logtype=none.

					  Caution

	      Setting the logtype=none attribute means that  the  volume  will
	      not  use a log even if you add one to the volume later. Adding a
	      log does not change the attribute setting.  To  enable  logging,
	      you  must	 stop the volume (volume stop volume_name), change the
	      logtype attribute	 (volume  set  logtype=drl  volume_name),  and
	      restart the volume (volume start volume_name). If the volume has
	      a log attached, logging is enabled. If the  volume  has  no  log
	      attached, adding one will enable logging.	 Specifies the default
	      maximum number of stripe columns for a RAID  5  volume  (default
	      value:  8).  Specifies the default maximum number of stripe col‐
	      umns, either for a RAID 5 volume (if max_nraid5stripe  is	 omit‐
	      ted)  or	for  a striped plex (default value: 8).	 Specifies the
	      maximum default dirty region log (DRL) subdisk length. If you do
	      not specify the DRL length for a volume, when creating the first
	      log for a mirrored volume, volassist uses a simple formula based
	      on  the log length. The default length will not be overridden by
	      max_regionloglen (default value: 32K).   Specifies  the  minimum
	      number  of  stripe columns for a RAID 5 volume. The default is 3
	      columns. The policy for selecting a default  number  of  RAID  5
	      stripe  columns  is  not	to allow a RAID 5 volume to have fewer
	      than min_nraid5stripe stripe columns. The minimum number of col‐
	      umns that you can have is 3.  Specifies the default minimum num‐
	      ber  of  stripe  columns	for  either  a	RAID  5	  volume   (if
	      min_nraid5stripe	is  omitted)  or  for  a striped plex (default
	      value: 2). The policy for selecting a default number  of	stripe
	      columns  is  not	to  allow  fewer  than this number of columns.
	      Specifies mirroring parameters. A	 decimal  number  indicates  a
	      specific	number	of mirrors to create, when creating a mirrored
	      volume (equivalent to nmirror=number). A value of yes  indicates
	      that  volumes  should be mirrored by default (equivalent to lay‐
	      out=mirror). A value of no  indicates  that  volumes  should  be
	      unmirrored  by  default (equivalent to layout=nomirror).	Speci‐
	      fies the permissions for the block and  character	 device	 nodes
	      created for a new volume. The mode can be specified either as an
	      octal number or symbolically. A symbolic mode is specified using
	      the  syntax  given in chmod(1). This attribute is used only with
	      the make operation.  The default mode for a  volume  gives  read
	      and  write  access  only	to the owner.  Specifies the number of
	      logs to create, by default, for a	 RAID  5  or  mirrored	volume
	      (presuming  that	logs  will  be created). The number of logs to
	      create can be specified independently for	 RAID  5  or  mirrored
	      volumes  using  the nraid5log and nregionlog attributes, respec‐
	      tively.  Specifies the number of mirrors to create when  mirror‐
	      ing  a  volume  (default value: 2).  Specifies the number of log
	      plexes to create for a new RAID 5	 volume	 (default  value:  1).
	      This  attribute is used only with the make operation.  Specifies
	      the number of stripe columns to use when creating a new  RAID  5
	      volume (the default is to adjust the number to available disks).
	      This attribute is used only with the make operation.   Specifies
	      the  number  of log subdisks to create for a new mirrored volume
	      (default value: 1). This attribute is used only  with  the  make
	      operation,  and  only  if	 logging  is requested for the volume.
	      Specifies the number of FPA logs to create and attach to a  vol‐
	      ume  (default value: same as the value of nlog, if set).	Speci‐
	      fies the number of stripe columns to use	when  creating	a  new
	      RAID  5  volume  (with  the  make	 operation) or when creating a
	      striped plex (with the make, mirror, and snapstart  operations).
	      The default is half of the candidate disks, adjusted to a number
	      between 2 and 8.	Specifies the stripe unit  size	 to  use  when
	      creating	a  new	RAID  5	 volume	 (default  value:  16K).  This
	      attribute is used only with the make operation.	Specifies  the
	      log  length to use when adding the first log to a RAID 5 volume.
	      The default is ten times the full stripe width (the stripe  unit
	      size  times  the	number	of stripe columns).  Specifies the log
	      subdisk length to use when adding the first  log	subdisk	 to  a
	      mirrored volume. The default is based on a formula involving the
	      volume length.  Specifies the stripe unit size to use when  cre‐
	      ating striped plexes to attach to a volume. When attaching a new
	      plex, the default is to use the same stripe  unit	 size  as  any
	      other  striped  plexes in the volume. If the volume does not yet
	      contain striped plexes, the default value is 64K.	 Specifies the
	      stripe  unit  size  to  use  for	either	a RAID 5 volume or for
	      striped plexes. This attribute can be used to set the values for
	      both raid5_stripeunit and stripe_stripeunit.  Specifies the own‐
	      ing user for a new volume (default value: root). The user can be
	      specified	 numerically  or  it  can be a system login name. This
	      attribute is used only with the make operation.	Specifies  the
	      usage type to use when creating a new volume with the make oper‐
	      ation (default value: raid5 for RAID  5  volumes;	 fsgen	other‐
	      wise).  The  usage type can also be specified in the option list
	      with -U.	Specifies a set	 of  desired  storage  specifications.
	      This  is	useful	in a defaults file to indicate desired storage
	      specifications that should be discarded if they fail to yield  a
	      reasonable set of allocations. The format is the same as for the
	      alloc attribute (a comma-separated list  of  storage  specifica‐
	      tions).

   Layout Specifications
       The  layout  attribute  specifies  a comma-separated list of parameters
       (with no arguments) that define how the	volassist  command  creates  a
       volume.

       Layout  specifications are: Specifies whether or not the volumes should
       use concatenated plexes. This is the default.  Specifies whether or not
       the  volume  uses  mirrored  plexes or RAID 5 plexes. The default is to
       create the volume without mirror or RAID 5 plexes.  When creating a new
       volume  or adding a plex to a volume that does not have a striped plex,
       the default is nostripe. When adding a new plex to a volume that has  a
       striped	plex,  the  default  is stripe.	 Allows (default) or disallows
       plexes, stripe columns, or RAID	5  stripe  columns  to	span  multiple
       disks.  If  nospan  is  indicated, plexes or columns can be formed from
       multiple regions of the same disk, but cannot be formed from more  than
       one  disk.   Disallows  or  allows (default) plexes, stripe columns, or
       RAID 5 stripe columns to use multiple regions of	 disk.	If  contig  is
       specified,  plexes and columns must be allocated from a single contigu‐
       ous region of disk.  If this is not possible, the allocation fails.  By
       default,	 the  volassist	 command tries to allocate space contiguously,
       but will use multiple regions or multiple  disks	 if  needed.   Creates
       (default)  or  doesn't create a DRL or RAID 5 log plex. You can specify
       this attribute independently for volumes that use mirrored and  RAID  5
       plexes  by  using the raid5log and regionlog layout specifications. You
       must use the -f option to create a volume that uses a RAID 5 plex  with
       the  nolog  attribute.	Creates (default) or doesn't create log plexes
       for volumes that use a RAID 5 plex. The -f option  must	be  used  with
       noraid5log  to  override	 the  default  behavior.  Creates (default) or
       doesn't create a DRL for volumes that use mirror	 plexes.   Creates  an
       FPA log for volumes that use mirror plexes.

EXIT CODES
       The  volassist  command	exits  with  a nonzero status if the attempted
       operation fails. A nonzero exit code is not a complete indicator of the
       problems	 encountered, but rather denotes the first condition that pre‐
       vented further execution of the command.

       See volintro(8) for a list of standard exit codes.

EXAMPLES
       Create a mirrored, concatenated 600 MB volume using disks dsk6 and dsk7
       in disk group dg1: # volassist -g dg1 -U gen make newvol 600m nmirror=2
       init=active dsk6 dsk7 Exclude a disk from being used in a new volume: #
       volassist make volA 4g nstripe=4 nmirror=2 !dsk8 Create a RAID 5 volume
       striped over five columns: #  volassist	make  bigvol  3g  layout=raid5
       ncolumn=5  Create a mirrored volume with DRL disabled: # volassist make
       vol1 1g layout=mirror,nolog Add a mirror to a volume: # volassist  mir‐
       ror  myvol  Add a mirror to a volume, specifying which disks to use for
       the mirror: # volassist -g dg1 mirror  bigvol  layout=stripe  ncolumn=4
       dsk6  dsk7 dsk8 dsk9 Add a log to a mirrored or RAID 5 volume, specify‐
       ing which disk to use for the log: # volassist -g dg1 addlog volB dsk10
       Enable  FPA  logging  on	 a  volume: # volassist addfpa vol09 loglen=65
       nfpalog=2 dsk11 dsk12 Use the fast plex attach feature to create a sec‐
       ondary  (backup) volume: # volassist snapfast vol09 vol09_Monday_backup
       Reattach the migrant plex to the primary volume	and  remove  the  sec‐
       ondary volume: # volassist snapback vol09_Monday_backup vol09 Determine
       the largest striped, three-way mirrored, four-column  volume  that  you
       can make in the dg2 disk group, excluding dsk8: # volassist -g dg2 max‐
       size layout=stripe ncolumn=4 nmirror=3 !dsk8

FILES
       System default settings file  for  volassist  attributes.  This	is  an
       optional, user-created file that resides in the /etc/default directory,
       which is also user-created.

SEE ALSO
       Commands: voledit(8),  volmake(8),  volmend(8),	volplex(8),  volsd(8),
       volume(8)

       Other: volintro(8)

								  volassist(8)
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