volume-request(4)														 volume-request(4)

NAME

       volume-request, volume-defaults - Solaris Volume Manager configuration information for top down volume creation with metassist

SYNOPSIS

       /usr/share/lib/xml/dtd/volume-request.dtd

       /usr/share/lib/xml/dtd/volume-defaults.dtd

       /etc/defaults/metassist.xml

       A  volume  request file, XML-based and compliant with the volume-request.dtd Document Type Definition, describes the characteristics of the
       volumes that metassist should produce.

       A system administrator would use the volume request file instead of providing options at the command line to give  more	specific  instruc-
       tions about the characteristics of the volumes to create. A volume request file can request more than one volume, but all requested volumes
       must reside in the same disk set.

       If you start metassist by providing a volume-request file as input, metassist can implement the configuration specified in  the	file,  can
       generate  a  command file that sets up the configuraiton for you to inspect or edit, or can generate a volume configuration file for you to
       inspect or edit.

       As a system administrator, you would want to create a volume request file if you need to reuse configurations (and do not want  to  reenter
       the same command arguments), or if you prefer to use a configuration file to specify volume characteristics.

       Volume  request	files  must  be  valid	XML  that  complies  with  the document type definition in the volume-request.dtd file, located at
       /usr/share/lib/xml/dtd/volume-request.dtd. You create a volume request file, and provide it as input to metassist to  create  volumes  from
       the top down.

   Defining Volume Request
       The  top  level	element  <volume-request>  surrounds the volume request data. This element has no attributes. A volume request requires at
       least one <diskset> element, which must be the first element after <volume-request>.

       Optionally, the <volume-request> element can include one or more <available> and <unavailable> elements to  specify  which  controllers	or
       disks associated with a specific controller can or cannot be used to create the volume.

       Optionally,  the  <volume-request>  element can include a <hsp> element to specify characteristics of a hot spare pool if fault recovery is
       used.

       If not specified for a volume with fault-recovery, the first hot spare pool found in the disk set is used. If no hot spare pool exists  but
       one is required, a hot spare pool is created.

       Optionally, the volume-request can include one or more <concat>, <stripe>, <mirror>, <volume> elements to specify volumes to create.

   Defining Disk Set
       Within  the <volume-request> element, a <diskset> element must exist. The <diskset> element, with the name attribute, specifies the name of
       the disk set to be used. If this disk set does not exist, it is created. This element and the name attribute are required.

   Defining Availability
       Within the <volume-request> element and within other elements, you can specify available or unavailable components (disks, or  disks  on  a
       specific controller path) for use or exclusion from use in a volume or hot spare pool.

       The  <available>  and <unavailable> elements require a name attribute which specifies either a full ctd name, or a partial ctd name that is
       used with the implied wildcard to complete the expression. For example, specifying c3t2d0 as available would look like:

       <available name="/dev/dsk/c3t2d0">

       The <available> element also makes any unnamed components unavailable. Specifying all controllers exept c1 unavailable would look like:

       <available name="c1">

       Specifying all disks on controller 2 as unavailable would look like:

       <unavailable name="c2">

       The <unavailable> element can also be used to further restrict the list of available components. For example,  specifying  all  controllers
       exept c1 unavailable, and making all devices associated with c1t2 unavailable as well would look like this:

       <available name="c1">
       <unavailable name="c1t2">

       Components specified as available must be either part of the named disk set used for this volume creation, or must be unused and not in any
       disk set. If the components are selected for use, but are not in the specified diskset, the metassist command automatically  adds  them	to
       the diskset.

       It  is  unnecessary to specify components that are in other disk sets as unavailable. metassist automatically excludes them from considera-
       tion. However, unused components or components that are not obviously used (for example, an unmounted slice that is reserved for  different
       uses) must be explicitly specified as unavailable, or the metassist command can include them in the configuration.

   Defining Hot Spare Pool
       The  next  element within the <volume-request> element, after the <diskset> and, optionally, <available> and <unavailable> elements, is the
       <hsp> element. Its sole attribute specifies the name of the hot spare pool:

       <hsp name="hsp001">

       The hot spare pool names must start with hsp and conclude with a number, thus following the existing Solaris Volume Manager hot spare  pool
       naming requirements.

       Within  the  <hsp>  element, you can specify one or more <available> and <unavailable> elements to specify which disks, or disks associated
       with a specific controller can or cannot be used to create the hot spares within the pool.

       Also within the <hsp> element, you can use the <slice> element to specify hot spares to be included in the hot  spare  pool  (see  DEFINING
       SLICE).	Depending on the requirements placed on the hot spare pool by other parts of the volume request, additional slices can be added to
       the hot spare pool.

   Defining Slice
       The <slice> element is used to define slices to include or exclude within other elements. It requires only a name attribute to specify  the
       ctd  name  of  the  slice,  and the context of the <slice> element determines the function of the element. Sample slice elements might look
       like:

       <slice name="c0t1d0s2" />
       <slice name="c0t12938567201lkj29561sllkj381d0s2" />

   Defining Stripe
       The <stripe> element defines stripes (interlaced RAID 0 volumes) to be used in a volume. It can contain either slice elements  (to  explic-
       itly  determine	which slices are used), or appropriate combinations of available and unavailable elements if the specific determination of
       slices is to be left to the metassist command.

       The <stripe> element takes an optional name attribute to specify a name. If the name is not specified, an available name  is  automatically
       selected from available Solaris Volume Manager names. If possible, names for related components are related.

       The  <stripe>  element  takes an optional size attribute that specifies the size as value and units (for example, 10TB, 5GB). If slices for
       the <stripe> are explicitly specified, the size attribute is ignored. The <available> and <unavailable> elements can be used  to  constrain
       slices for use in a stripe.

       The  <stripe>  elements takes optional mincomp and maxcomp attributes to specify both the minimum and maximum number of components that can
       be included in it. As with size, if slices for the <stripe> are explicitly specified, the mincomp and maxcomp attributes are ignored.

       The <stripe> elements takes an optional interlace attribute as value and units (for example, 16KB, 5BLOCKS, 20KB). If  this  value  is  not
       specified, the Solaris Volume Manager default value is used.

       The  <stripe>  element  takes  an  optional  usehsp attribute to specify if a hot spare pool should be associated with this component. This
       attribute is specified as a boolean value, as usehsp="TRUE". If the component is not a submirror, this attribute is ignored.

   Defining Concat
       The <concat> element defines concats (non-interlaced RAID 0 volumes) to be used in a configuration. It is specified in the same	way  as  a
       <stripe> element, except that the mincomp, maxcomp, and interlace attributes are not valid.

   Defining Mirror
       The  <mirror>  element  defines	mirrors (RAID 1 volumes) to be used in a volume configuration. It can contain combinations of <concat> and
       <stripe> elements (to explicitly determine which volumes are used as submirrors). Alternatively, it can have a  size  attribute	specified,
       along  with  the  appropriate  combinations  of available and unavailable elements to leave the specific determination of components to the
       metassist command.

       The <mirror> element takes an optional name attribute to specify a name. If the name is not specified, an available name  is  automatically
       selected.

       The  <mirror> element takes an optional size attribute that specifies the size as value and units (for example, 10TB, 5GB). If <stripe> and
       <concat> elements for the mirror are not specified, this attribute is required. Otherwise, it is ignored.

       The <mirror> element takes an optional nsubmirrors attribute to define the number of submirrors (1-4) to include. Like the size	attribute,
       this  attribute	is  ignored  if  the  underlying  <concat> and <stripe> submirrors are explicitly specified. The <mirror> element takes an
       optional read attribute to define the mirror read options (ROUNDROBIN, GEOMETRIC, or FIRST) for the mirror. If this attribute is not speci-
       fied, the Solaris Volume Manager default value is used.

       The  <mirror>  element takes an optional write attribute to define the mirror write options (PARALLEL, SERIAL, or FIRST) for the mirror. If
       this attribute is not specified, the Solaris Volume Manager default value is used.

       The <mirror> element takes an optional usehsp attribute to specify if a hot spare pool should  be  associated  with  each  submirror.  This
       attribute  is  specified as a boolean value, as usehsp="TRUE". If the usehsp attribute is specified in the configuration of the <stripe> or
       <concat> element used as a submirror, it overrides the value of usehsp attributes for the mirror as a whole.

   Defining Volume by Quality of Service
       The <volume> element defines volumes (high-level) by the quality of service they should provide. (The  <volume>	element  offers  the  same
       functionality that options on the metassist command line can provide.)

       The  <volume>  element  can contain combinations of <available> and <unavailable> elements to determine which components can be included in
       the configuration.

       The <volume> element takes an optional name attribute to specify a name. If the name is not specified, an available name  is  automatically
       selected.

       The <volume> element takes a required size attribute that specifies the size as value and units (for example, 10TB, 5GB).

       The <volume> element takes an optional redundancy attribute to define the number of additional copies of data (1-4) to include. In a worst-
       case scenario, a volume can suffer failure of n-1 components without data loss, where redundancy=n. With fault recovery options, the volume
       could  withstand up to n+hsps-1 non-concurrent failures without data loss. Specifying redundancy=0 results in a RAID 0 volume being created
       (a stripe, specifically).

       The <volume> element takes an optional faultrecovery attribute to determine if additional components should be allocated  to  recover  from
       component  failures  in	the  volume.  This  is used to determine whether the volume is associated with a hot spare pool. The faultrecovery
       attribute is a boolean attribute, with a default value of FALSE.

       The <volume> element takes an optional datapaths attribute to determine if multiple data paths should be required to access the volume. The
       datapaths attribute should be set to a numeric value.

   Defining Default Values Globally
       Global  defaults  can  be  set  in /etc/default/metassist.xml. This volume-defaults file can contain most of the same elements as a volume-
       request file, but differs structurally from a volume-request file:

	 o  The container element must be <volume-defaults>, not <volume-request>.

	 o  The <volume-defaults> element can contain <available>, <unavailable>, <hsp>, <concat>, <stripe>, <mirror>, or <volume> elements.

	    Attributes specified by these elements define global default values, unless overridden by the corresponding attributes and elements in
	    a volume-request. None of these elements is a container element.

	 o  The  <volume-defaults> element can contain one or more <diskset> elements to provide disk set-specific defaults. The <diskset> element
	    can contain <available>, <unavailable>, <hsp>, <concat>, <stripe>, <mirror>, or <volume> elements.

	 o  Settings specified outside of a <diskset> element apply to all disk sets, but can be overridden within each <diskset> element.

       Example 1: Creating a Redundant Volume

       The following example shows a volume request file used to create a redundant and fault tolerant volume of 1TB.

       <volume-request>
	 <diskset name="sparestorage"/>
	 <volume size="1TB" redundancy="2" faultrecovery="TRUE">
	   <available name="c2" />
	   <available name="c3" />
	   <unavailable name="c2t2d0" />
	 </volume>
       </volume-request>

       Example 2: Creating a Complex Configuration

       The following example shows a sample volume-request file that specifies a disk set name, and specifically itemizes characteristics of  com-
       ponents to create.

       <volume-request>

	   <!-- Specify the disk set to use -->
	   <diskset name="mailspool"/>

	   <!-- Generally available devices -->
	   <available name="c0"/>

	   <!-- Create a 3-way mirror with redundant datapaths and HSPs /
		 via QoS -->
	   <volume size="10GB" redundancy="3" datapaths="2" /
		 faultrecovery="TRUE"/>

	   <!-- Create a 1-way mirror with a HSP via QoS -->
	   <volume size="10GB" faultrecovery="TRUE"/>

	   <!-- Create a stripe via QoS -->
	   <volume size="100GB"/>

       </volume-request>

BOUNDARY VALUES

       Attribute       Minimum	       Maximum
       mincomp	       1	       N/A
       maxcomp	       N/A	       32
       nsubmirrors     1	       4
       passnum	       0	       9
       datapaths       1	       4
       redundancy      0	       4

       /usr/share/lib/xml/dtd/volume-request.dtd

       /usr/share/lib/xml/dtd/volume-defaults.dtd

       /etc/defaults/metassist.xml

       metassist(1M), metaclear(1M), metadb(1M), metadetach(1M), metahs(1M), metainit(1M), metaoffline(1M), metaonline(1M), metaparam(1M), metare-
       cover(1M), metareplace(1M), metaroot(1M), metaset(1M), metasync(1M), metattach(1M), mount_ufs(1M), mddb.cf(4)

								    27 Apr 2005 						 volume-request(4)