volume-request(4) File Formats 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
DESCRIPTION
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 vol‐
umes 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 cre‐
ated. 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 spe‐
cific 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 consideration.
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 num‐
ber, 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 spec‐
ify 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 deter‐
mines 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 explicitly
determine which slices are used), or appropriate combinations of avail‐
able 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> sub‐
mirrors 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:
· The container element must be <volume-defaults>, not <volume-
request>.
· The <volume-defaults> element can contain <available>, <unavail‐
able>, <hsp>, <concat>, <stripe>, <mirror>, or <volume> elements.
Attributes specified by these elements define global default val‐
ues, unless overridden by the corresponding attributes and ele‐
ments in a volume-request. None of these elements is a container
element.
· The <volume-defaults> element can contain one or more <diskset>
elements to provide disk set-specific defaults. The <diskset> ele‐
ment can contain <available>, <unavailable>, <hsp>, <concat>,
<stripe>, <mirror>, or <volume> elements.
· Settings specified outside of a <diskset> element apply to all
disk sets, but can be overridden within each <diskset> element.
EXAMPLES
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 compo‐
nents 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
FILES
/usr/share/lib/xml/dtd/volume-request.dtd
/usr/share/lib/xml/dtd/volume-defaults.dtd
/etc/defaults/metassist.xml
SEE ALSOmetassist(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)
Solaris Volume Manager Administration Guide
SunOS 5.10 27 Apr 2005 volume-request(4)
