vxassist(1M) VxVM 3.5 vxassist(1M)
1 Jun 2002
NAME [Toc] [Back]
vxassist - create, relayout, convert, mirror, backup, grow, shrink,
delete, and move volumes
SYNOPSIS [Toc] [Back]
vxassist [ options ] [ -b ] addlog volume [ attribute...]
vxassist [ options ] [ -b ] convert volume [ attribute...]
vxassist [ options ] [ -b ] growby volume lengthchange [ attribute...]
vxassist [ options ] [ -b ] growto volume newlength [ attribute...]
vxassist help { alloc | attrs | layout | mirror | options | showattrs |
space | usage }
vxassist [ options ] [ -b ] make volume length [ attribute...]
vxassist [ options ] [ -b ] maxgrow volume [ attribute...]
vxassist [ options ] [ -b ] maxsize [ attribute...]
vxassist [ options ] [ -b ] mirror volume [ attribute...]
vxassist [ options ] [ -b ] move volume storage-spec... [ attribute...]
vxassist [ options ] [ -b ] relayout { volume| plex} [ attribute...]
vxassist [ options ] remove { volume | mirror | log } volume [storage-
spec...] [ attribute...]
vxassist [ options ] shrinkby volume lengthchange [ attribute...]
vxassist [ options ] shrinkto volume newlength [ attribute...]
vxassist [ options ] snapabort volume
vxassist [ options ] snapback snapvolume
vxassist [ options ] snapclear volume [snap_object]
vxassist [ options ] snapprint [volume]
vxassist [ options ] snapshot volume snapvolume [ attribute...]
vxassist [ options ] [ -b ] snapstart volume [ attribute...]
vxassist [ options ] snapwait volume
DESCRIPTION [Toc] [Back]
The vxassist utility is a command-line interface to the VERITAS Volume
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Manager (VxVM) that:
+ Finds space for and creates volumes
+ Performs volume conversion
+ Adds mirrors and logs to existing volumes
+ Extends and shrinks existing volumes
+ Migrates data from a specified set of disks
+ Provides facilities for the online backup of existing volumes
Specify the appropriate keyword to vxassist to select an action to
perform.
Each operation can be applied to only one disk group at a time. For
most keywords, the volume operand specifies the volume on which to
operate. For the make operation, attributes that name specific disks
can be used to determine a default disk group, according to the
standard disk group selection rules described in vxintro(1M). A
specific disk group can be specified with -g diskgroup. If no disk
attributes are specified, the make operation defaults to using the
rootdg disk group. You can specify an alternate default disk group in
a defaults file (usually /etc/default/vxassist).
Many vxassist operations can take a set of attributes that specify
such things as how to lay out volumes, or on which sets of disks to
build them. There are two basic types of attributes:
+ storage specifications
+ attribute settings
Storage specification attributes are either simple disk names (for
example, disk01), or groups of disks selected by controller or target.
For example, ctlr:c1 specifies all disks on controller 1.
You can exclude (negate) storage specification by specifying the
exclamation character (!) prefix. (Note: You may also need to escape
the ! character to prevent it being interpreted by the shell.) For
example, you can combine the arguments ctlr:c1 and !target:c1t5 to
indicate that storage be allocated from controller 1, but not from
SCSI target 5 on that controller.
Other attributes are of the form attrname=value; these additional
attributes can specify the type of a volume (mirrored, RAID-5,
striped, logged), layout policies (contiguous, spanning), mirroring
requirements (mirror across controllers), and constraint parameters
(constrain allocations to a single controller). See the ATTRIBUTES
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section below for a complete list of attribute specifications.
If no non-excluded storage specification attributes are given, any
non-reserved, non-volatile, non-spare, non-excluded disk can be used
to allocate storage. Attributes may constrain the selection,
particularly with respect to the selection of multiple disks. For
example, the command:
vxassist make mirvol 500m layout=mirror,log mirror=ctlr !ctlr:c2
requests that vxassist create a new mirrored volume on any disks that
are not on controller 2. The mirror=ctlr attribute constrains the
selection of disks so that the mirrors are created on different
controllers.
KEYWORDS [Toc] [Back]
addlog Adds a log or DCO to a volume.
DCO is a data change object, used for Persistent FastResync.
DRL is a dirty region log, used for speedy recovery of
mirrors after a system crash.
Sequential DRL is a form of DRL that is optimized for
volumes that are written to sequentially, such as database
log volumes.
DCM is a data change map, used for fast resynchronization of
a secondary RVG with its primary.
Mirrored volumes are associated with DRL or sequential DRL
logs.
RAID-5 volumes are associated with RAID-5 logs.
Replicated volumes are associated with DCM logs.
By default, when adding a log, vxassist attempts to
determine the correct type of log to add, even if no logtype
attribute is specified. For example, if the volume is part
of an RVG, vxassist attempts to create a DCM log.
When adding a DRL, RAID-5 or DCM log to a volume for the
first time, the loglen attribute can be used to specify the
length of the log; on adding additional logs, the loglen
attribute is ignored and the existing log length is used. If
a loglen which is too large or small to be practical is
specified, vxassist may adjust the length to a reasonable
size. If no loglen attribute is supplied, vxassist picks an
appropriate log size. Other attributes can be specified to
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indicate desired properties for the new allocations.
Mirroring constraints do not apply to logs, though storage
constraints can be specified that limit the logs to disk
sets already used by the volume.
Adding a DCO to a volume creates a DCO object that is
associated with the volume, and a DCO volume that is
associated with the DCO object. When created for a nonlayered
volume with at least 2 data plexes or for any
layered volume, the default DCO volume has 2 DCO plexes
(mirrors for redundancy), each of length 132 blocks. When
created for a non-layered volume with a single data plex,
the default DCO volume has a single unmirrored DCO plex of
length 132 blocks.
Note: To allow operation of the dynamic disk group
split/join feature (see vxdg(1M) for more information),
vxassist attempts to place DCO plexes on the same disks as
the plexes of the corresponding data volume. This
allocation policy may not succeed if there is insufficient
disk space. vxassist then uses available space in the
remaining disks of the disk group. This may prevent certain
disk group split or move operations if the DCO plexes cannot
accompany their parent data volume. To overcome this, you
can use storage specifications to specify explicitly the
disks on which the DCO plexes are to be configured.
Note: Adding a DCO does not enable Persistent FastResync on
the parent volume unless fastresync=yes is also specified.
Adding a DRL log to a mirrored volume creates a single log
subdisk and a new plex to contain that subdisk. The new plex
is then be attached to the volume. DRL logging can co-exist
with DCO.
Adding a RAID-5 log to a RAID-5 volume involves creating a
new plex that is attached to the volume as a log plex.
Adding a DCM log to a replicated volume adds two logs (by
default), each consisting of a log plex and associated
subdisk. DCM logging can co-exist with DCO.
convert Converts a volume layout to a mirror-stripe from a stripemirror,
or from a mirror-stripe to a stripe-mirror. Also
converts to mirror-concat from a concat-mirror, or from a
mirror-concat to a concat-mirror.
growby | growto
Increases the length of the named volume to the length
specified by newlength (growto), or by the length specified
by lengthchange (growby). Specify the new length, or change
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in length, in VERITAS Volume Manager standard lengths (see
vxintro(1M)). 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 subdisks in
the volume, or by adding and associating new subdisks.
Plexes that are not already fully populated (that is,
sparse) are left unchanged. Log-only plexes are also left
unchanged.
Note: Following a relayout, specify the attribute
layout=nodiskalign to the growby and growto commands if you
want the subdisks to be grown using contiguous disk space.
Note: When you grow a volume, it is recommended that you
also grow any file system that is configured on that volume
(see vxresize(1M)). vxassist does not resize file systems
(or other uses of the volume, such as databases) that reside
on the volume. If necessary, use the appropriate
application command to adjust the layout of data in the
volume after the grow operation has finished.
When a volume is grown, the volume may be converted from one
layout to another as a side effect. For example, a volume
that has the mirror-stripe layout may be converted to
stripe-mirror when it is grown. This kind of conversion is
done if vxassist determines that the new volume is too small
or large for the original layout. If the new volume layout
is inappropriate, use the convert operation between layered
and non-layered forms. See Layout Specifications for a
description of the methods used to determine disk layouts.
Note: You cannot resize volumes comprised of different plex
layouts. If you try to do so, an error message displays
stating that the volume contains differing layouts.
You can specify attributes to indicate properties for the
new allocations. Any mirroring constraints still apply
between all extensions to the existing mirrors and the other
mirrors. Growing of a volume requires that the volume be
enabled.
When the size of a replicated volume changes, you can ensure
that the size of the DCM is appropriate by removing all the
DCM logs and adding them back without specifying the loglen
attribute.
help Displays information on vxassist usage and VERITAS Volume
Manager attributes. For example, to display information
about using vxassist attributes, enter:
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vxassist help attributes
make Creates a volume with the specified name and the specified
length. The length is specified as a standard VERITAS
Volume Manager length (see vxintro(1M)). You can specify
attributes to indicate various properties and storage
locations for the created volume. See Layout Specifications
for a description of the methods used to determine disk
layouts.
maxgrow Reports the maximum size a volume can grow given its
attributes and given the free storage available.
maxsize Reports the maximum size a volume could be created with
given the attributes specified and given the free storage
available.
mirror Creates a new mirror (or plex) and attaches it to the
volume. This operation is allowed only if the volume is
enabled. Attributes can be specified to indicate various
desired properties and storage locations for the created
volume. Attributes that constrain mirroring (such as
requiring that mirrors be on separate groups of disks) apply
between the existing mirrors of the volume and the new
mirror.
move Moves subdisks within the named volume off the excluded
storage specified on the command line. Excluded storage is
specified with a prefix of !. The move operation requires
that at least one excluded storage specification be given.
If the volume is enabled, subdisks within detached or
disabled plexes (or detached log or RAID-5 subdisks) are
moved without recovery of data. If the volume is not
enabled, stale log or RAID-5 subdisks, or subdisks within
STALE or OFFLINE plexes, are moved without recovery; if
there are other subdisks within a non-enabled volume that
require moving, the move operation fails.
For enabled subdisks in enabled plexes within an enabled
volume, the data within subdisks are moved to the new
location, without loss of availability (or redundancy) of
the volume.
relayout Changes a volume layout or properties. This operation
changes the number of columns in a stripe or the stripe
width of a volume. It also converts a volume to or from
RAID-5, concatenated-mirror, striped, striped-mirror or any
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similar layout.
Note: The relayout operation internally generates unique
data object names (for example, v2-Dp02) when it converts a
volume to a specified destination layout.
Note: Following a relayout, specify the attribute
layout=nodiskalign to the growby and growto commands if you
want the subdisks to be grown using contiguous disk space.
After relayout to a layered form, a volume may be converted
to a non-layered form. For example, to convert from a 4-
column mirror-stripe to a 5-column mirror-stripe, first
relayout the volume as a stripe-mirror:
vxassist relayout vol1 nstripe=5
If you view the volume with vxprint during relayout, the
volume shows several subvolumes that are used during the
change, and a more complex configuration than usual.
After the new column is added, the volume is in stripemirror
layout. Use vxassist convert to convert back to a
mirror-stripe layout:
vxassist convert vol1 layout=mirror-stripe
Note: If the system crashes during relayout or conversion,
the process continues when the system is rebooted. However,
if the crash occurred during the first stage of a two-stage
relayout and convert operation, only the first stage is
subsequently completed after rebooting. You must run
vxassist convert manually to complete the second stage.
remove volume | mirror | log
Deletes the entire volume, one or more mirrors, or one or
more logs, according to the argument. When deleting a
mirror or a log, specify the storage to be removed using the
attribute form !diskname (see Storage Specifications below).
For example, to remove a mirror on disk01, enter:
vxassist remove mirror vol01 !disk01
See vxplex(1M) for an example of an alternative method of
removing a mirror from a volume.
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Use the logtype= attribute to specify the type of log to be
removed. For example, specify logtype=drl to remove a DRL
log.
Note: Specifying logtype=dco completely removes the DCO
object, DCO volume and any snap objects that are associated
with the specified volume, and also disables FastResync on
the volume.
The alloc=, nmirror=, and nlog= attributes also determine
the number of mirrors or logs remaining after the remove
operation completes. When the number of mirrors drops to 1,
logs are also removed.
By default, vxassist removes 1 mirror or 1 log.
shrinkby | shrinkto
Decreases the length of the named volume to the length
specified by newlength (shrinkto), or by the length
specified by lengthchange (shrinkby). Specify the new
length, or change in length, in VERITAS Volume Manager
standard lengths (see vxintro(1M)). 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 requested
volume length. The freed space can then be allocated for
use by other volumes. Log-only plexes are left unchanged.
When a volume is shrunk, the volume may be converted from
one layout to another as a side effect. For example, a
volume that has the mirror-stripe layout may be converted to
stripe-mirror when it is shrunk. This kind of conversion is
done if vxassist determines that the new volume is too small
or large for the original layout. If the new volume layout
is inappropriate, use the convert operation between layered
and non-layered forms. See Layout Specifications for a
description of the methods used to determine disk layouts.
Note: You cannot resize volumes comprised of different plex
layouts. If you try to do so, an error message displays
stating that the volume contains differing layouts.
Caution: Data can be lost or corrupted if file systems or
other organized data residing on a volume are not shrunk
before shrinking the volume. vxassist does not resize file
systems (or other uses of the volume, such as databases)
that reside on the volume. You can use the vxresize command
to shrink file systems on the volume (see vxresize(1M)).
Otherwise, use the appropriate application command to adjust
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the layout of data in the volume before initiating the
shrink operation.
snapabort Removes the mirror snapshot when a snapstart mirror has been
started (and eventually completed).
snapback By default, finds one plex in the snapshot volume that has
the snap_rid field set, and attaches it to the original
volume. If the plex is the last in a volume, that volume is
removed from the disk group.
Note: The snapshot volume and the original volume must be in
the same disk group.
If the -o allplexes option is specified, all snapshot plexes
in the same disk group are reattached. Alternatively, if
the nmirror=number attribute is specified, only number
plexes are reattached.
The direction of the resynchronization can be determined by
specifying either resyncfromoriginal or resyncfromreplica as
the useopt argument to the -o option. To choose the
original volume as the preferred copy of the data, use -o
resyncfromoriginal. To choose the replica as the preferred
copy of the data, use -o resyncfromreplica.
Note: You must unmount the original volume (if mounted)
before using the -o resyncfromreplica option. Similarly,
you must unmount the snapshot volume (if mounted) before
using the -o resyncfromoriginal option.
snapclear Clears the FastResync map, removes any snap objects, and
clears the snap_rid field of the volume.
Note: snapback cannot be invoked after snapclear is used.
If Persistent FastResync is enabled and the original volume
and the snapshot volume are in different disk groups,
snapclear removes the snap object and clears the FastResync
map for the snapshot volume that corresponds to the snapshot
object. To stop tracking on the original volume for the
snapshot volume, specify the snap object, snap_object, in
the original volume that refers to the snapshot volume. You
must also run vxassist snapclear separately on the snapshot
volume. For example, if myvol1 and SNAP-myvol1 are in
separate disk groups mydg1 and mydg2 respectively, the
following command stops tracking on myvol1 with respect to
SNAP-myvol1:
vxassist -g mydg1 snapclear myvol1 SNAP-myvol1_snp
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However, tracking is still enabled on SNAP-myvol1 with
respect to myvol1. The following command turns this tracking
off by specifying the snap object, myvol1_snp, in SNAP-
myvol1 that points to myvol1:
vxassist -g mydg2 snapclear SNAP-myvol1 myvol1_snp
If Persistent FastResync is enabled and the original volume
and the snapshot volume are in the same disk group,
snapclear removes the snap records for both the original
volume and the snapshot volume in addition to clearing their
FastResync maps.
Note: Either of the two previous examples stops Persistent
FastResync tracking for both the snapshot volume (SNAP-
myvol1) and the original volume (myvol1) if they are in the
same disk group.
To support Non-Persistent FastResync and to be compatible
with previous versions of VxVM, a single snapshot volume can
be specified as the argument to snapclear, for example:
vxassist -g myolddg snapclear SNAP-myoldvol
snapprint Displays the associations between the original volumes and
their respective replicas. If a volume is specified, output
is displayed only for that volume. An error message is
displayed if FastResync is not enabled on the volume.
The following information is displayed:
+ Name of the original volume.
+ Names of all snapshot volumes.
+ Length in blocks of the volume, detached plex, or
snapshot plex.
+ Percentage of the snapshot plex or detached plex that is
considered to have been changed (dirty). For NonPersistent
FastResync, which keeps information about
changed regions in a single map for the original volume
and its snapshot volumes, the %DIRTY value is the same
for the original volume as for a snapshot volume even if
writes are only made to the snapshot volume. For
Persistent FastResync, which maintains separate tracking
maps for the original volume and each of its snapshot
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volumes, the %DIRTY value is based only on what has been
written to an individual volume.
In the following example, Persistent FastResync is enabled
on volume v1, and Non-Persistent FastResync on volume v2. V
and v indicate the volume, DP and dp indicate detached
plexes, and SS and ss indicate snapshot plexes.
# vxassist -g mydg snapprint v1
V NAME USETYPE LENGTH
SS SNAPOBJ NAME LENGTH %DIRTY
DP NAME VOLUME LENGTH %DIRTY
v v1 fsgen 20480
ss SNAP-v1_snp SNAP-v1 20480 4
dp v1-01 v1 20480 0
dp v1-02 v1 20480 0
v SNAP-v1 fsgen 20480
ss v1_snp v1 20480 0
# vxassist -g mydg snapprint v2
V NAME USETYPE LENGTH
SS SNAPOBJ NAME LENGTH %DIRTY
DP NAME VOLUME LENGTH %DIRTY
v v2 fsgen 20480
ss -- SNAP-v2 20480 0
dp v2-01 v2 20480 0
v SNAP-v2 fsgen 20480
ss -- v2 20480 0
snapshot Creates a new volume by taking one or more attached
temporary mirrors (with state SNAPDONE) to use as its
plexes. The nmirror=number attribute can be used to specify
the number of mirrors in a snapshot volume. At least number
SNAPDONE plexes must be available in the original volume.
By default, one plex is used if nmirrors is not specified.
The comment attribute may also be used to set the comment
field for the snapshot volume.
The following are examples of the use of the nmirror and
comment attributes:
vxassist snapshot nmirror=2 \
comment="mirrored snapvol for myvol" myvol snapvol
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Some usage types attempt to synchronize any in-memory data
associated with the volume (such as unwritten file system
modifications) when the snapshot operation is done. In
particular, if the fsgen usage type is used with a volume
containing a VERITAS File System (VxFS), then cooperating
procedures ensure that all file system data is consistently
flushed to the volume. For hfs and other file system types,
the synchronization operation calls sync. This makes the
snapshot a better image, but it may leave some
inconsistencies between in-memory file system data and the
data residing on the backup image.
The snapshot command accepts more than one volume. All the
given volumes are split atomically (in a single
transaction). That is, all the given volumes are relatively
consistent as a result of taking the snapshot. If you
specify the -o allvols option without giving any volume
names, vxassist attempts to create a sufficiently long
vxplex command to take a snapshot of all the volumes in the
disk group. You can use the -o name=pattern option to
specify a name for the new volume. Otherwise, the default
name assigned to the new volume has the form SNAP%d-%v.
snapstart Creates a plex and attaches it to the named volume as a
snapshot mirror. When the attach completes, the plex has
state SNAPDONE and is a candidate for selection by the
snapshot operation. Attributes can be specified to indicate
the desired properties of the snapshot mirror.
The nmirror=number attribute can be used to specify the
number of snapshot plexes to be attached to a volume. By
default, number is 1.
Note: To allow operation of the dynamic disk group
split/join feature (see vxdg(1M) for more information),
vxassist attempts to avoid placing snapshot plexes on the
same disks as the plexes of the original volume or the
plexes of its associated DCO volume. This allocation policy
may not succeed if there is insufficient disk space.
vxassist then uses any other available space in the disk
group. This may prevent certain disk group split or move
operations if the snapshot plexes and their associated DCO
plexes cannot be physically separated from the plexes of the
original volume or the plexes of its DCO volume. To
overcome this, you can use storage specifications to specify
explicitly the disks on which the snapshot plexes are to be
configured.
snapwait Waits for an attached mirror to become available on a volume
if a snapstart mirror attach is done as a background task
(such as using the -b option). The operation exits when the
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snapshot is complete. Available snapshot plexes are flagged
with state SNAPDONE.
OPTIONS [Toc] [Back]
-b Performs extended operations in the background. This option
applies to plex consistency recovery operations for make,
growto and growby, to plex attach operations started by
mirror and snapstart, to relayout operations started by
relayout, and to the addlog, convert, maxgrow, maxsize, move
and remove operations.
-d defaults
Specifies a file containing defaults for various attributes
related to volume creation and space allocation. If not
specified, this defaults to /etc/default/vxassist.
-f Forces operations not usually allowed by vxassist.
-g diskgroup
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 medianame operands (if any) for the
vxassist make operation, or based on the volume operands for
all other operations.
-n Prevents the system defaults file being read.
-o useopt Passes in options specific to a usage type to the operation.
A certain set of operations are expected to be implemented
by all usage types:
allplexes Specifies that all available snapshot plexes in a
disk group are to be reattached to their original
volume during a snapback operation.
allvols Takes a snapshot of all the volumes in the disk
group. An error results if one or more volumes do
not have a plex that is usable for the snapshot.
iosize=size
Performs copy and recovery operations in regions
with the length specified by size, which is a
standard VERITAS Volume Manager length number (see
vxintro(1M)). Specifying a larger number typically
causes the operation to complete sooner, but with
greater impact on other processes using the
volume. The default I/O size is typically between
4 and 128 kilobytes.
name=pattern
Specifies the template for naming new snapshot
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volumes. The pattern consists of characters and
one or more of the following specifiers:
%% Single percent character.
%d Unique serialization number expressed as
a decimal integer.
%g Disk group name.
%m Mirror's original name.
%s Serialization string expressed as a
sequence of one or more lower case
letters.
%S Serialization string expressed as a
sequence of one or more upper case
letters.
%v Volume name.
%x Unique serialization number expressed as
a lower-case hexadecimal integer.
%X Unique serialization number expressed as
an upper case hexadecimal integer.
The default template name for a new snapshot volume is
SNAP%d-%v.
numchild=number
Specifies the number of child processes that are
used to perform resynchronization during a
snapback operation. The default value of number
is 1 (no child processes), which is the same as
specifying a number of 0. Specifying a larger
value for number potentially speeds up
resynchronization, although the effectiveness of
this depends to some extent on the underlying
characteristics of the disk array. No further
benefit in performance may be noticeable for a
value for number greater than 3.
By default, the child processes divide the volume
into equally sized chunks, which they then
resynchronize independently with the volume. This
behavior may be modified using the useopt
sequential.
Note: A large iosize of 1m or 2m is recommended
for use with this option.
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ordered Specifies that ordered allocation should be used
to create a new volume. For more information, see
the Ordered Allocation section below.
readonly Specifies that a read-only replica volume is
created during a snapshot.
renamesnapplex
Specifies that a snapshot plex is renamed when the
snapshot operation is used to create a snapshot
volume. If this option is not specified, the plex
retains the same name that it had in the original
volume.
resyncfromoriginal
Performs a resync using the data in the original
volume during a snapback.
resyncfromreplica
Performs a resync using the data in the snap plex
during a snapback.
sequential
When specified with the useopt numchild for values
of number greater than 1, the child processes cooperate
in resynchronizing regions of the volume
that are close together, starting at the beginning
of the volume and moving to the end. This creates
more overhead for the resynchronization, but it
potentially makes better use of the sequential
read-ahead buffer of the physical disks.
slow[=iodelay]
Reduces the impact on system performance of copy
operations. Copy and plex consistency recovery
operations are usually a set of short operations
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).
-p Prints only the maximum size with no text wrappers (used
with maxsize and maxgrow).
-r Includes spare disks (reserved for hot-relocation) in the
calculation.
-t tasktag
Marks any tasks that are registered to track the progress of
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an operation with the tag tasktag. This option is passed to
utilities called by vxassist, so any child tasks are also
tagged with tasktag. The tag specified by tasktag is a
sequence of up to 16 alphanumeric characters.
-U usetype
Limits the operation to volumes that have this usage type.
Any attempt to operate on volumes that have a different
usage type fails.
For a make operation, this option specifies the usage type
of the volume to be created. Otherwise, the default usage
type set in the /etc/default/vxassist file is used, or if
such an entry does not exist, the usage type is set to
fsgen.
-v Traces calls to other utilities to determine which VERITAS
Volume Manager commands vxassist is executing.
Hardware-Specific Options [Toc] [Back]
Some environments provide guidelines to optimize VxVM's interaction
with intelligent storage systems. If these guidelines are present,
VxVM follows the guidelines when creating volumes or allocating space
for volumes. By default, vxassist only creates volumes that conform
with these guidelines. The following options change the behavior of
vxassist operations make, mirror, grow and shrink :
-o override
Performs the specified vxassist task for the specified
volume and ignores any storage-specific guidelines.
Overriding the guidelines is not recommended as it can
result in incompatible objects, or objects that cannot be
administered by VxVM and any associated software that
exploit storage-specific features.
-o verify Verifies that the vxassist task for the specified volume can
be performed without violating any storage-specific
guidelines, but does not commit or perform any task. If any
guidelines are violated, vxassist exits with an error
message.
Note: These options need a separate license. Without the
license, vxassist ignores the specified option.
Refer to the vendor-specific documentation for more information on how
intelligent storage systems can interact with VxVM.
ATTRIBUTES [Toc] [Back]
Attribute values for various purposes can be specified with arguments
of the form attribute=value. Attributes can also be passed in through
a defaults file. Default attribute values can be stored in the file
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/etc/default/vxassist.
Attributes are selected according to the order in which they are
scanned. In general they are taken in decreasing priority of being
specified on:
1. The command line.
2. The specified defaults file (as supplied with the -d command line
argument).
3. The system defaults file (as specified in /etc/default/vxassist).
Attributes from all sources have the same form. However, in some
cases, command-line attributes change default behaviors in ways that
attributes in the defaults file 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 cause mirroring
or logging to happen by default. If such attributes are specified in a
defaults file, they indicate the attributes that would be used if
mirroring or logging were enabled.
Attributes are either storage specifications (possibly negated), or
are in the form attribute=value. In a defaults file, attributes are
separated by a space or are on separate lines. Blank lines in a
defaults file are ignored, and comments can be included with the
standard # convention.
Storage Specifications [Toc] [Back]
Storage specification attributes have one of the following forms:
[!]diskname
Specifies (or excludes) a disk. diskname refers to a disk
media record name in a VERITAS Volume Manager disk group.
[!]diskclass:instance
Specifies (or excludes) a set of disks. diskclass names a
particular type of disk grouping (for example, ctlr to
indicate groups of disks on a single controller), and
instance specifies which grouping of that type (for example
c1). Each type of disk class has a particular format for
specifying instances of the class.
diskclass:same
Specifies that the allocation must be constrained to include
disks from the same instance of the given class. For
example, a storage specification of diskparam:same indicates
that all disks selected must have the same basic parameters
(tracksize, cylinder size, size, and revolutions-perminute),
but does not specify which specific parameters to
use.
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The defined disk classes (and alternate names, or aliases, for those
classes) are as follows:
ctlr (alias: c, ctrl, cntrl, controller)
Specifies disks accessible through a controller group. All
disks accessible through the specified controller name(c#)
are selected for the operation.
For example, consider a configuration where two enclosures
are connected to a host. The first through controllers c1,
c2 and the second through controllers c3, c4. The command:
vxassist make vol1 1024 !ctlr:c1
results in disks from the first enclosure being excluded
from the operation because all disks in the first enclosure
are accessible through c1(and c2). The command:
vxassist make vol1 1024 !ctlr:c2
has the same effect (of excluding disks in the first
enclosure) in the above configuration. The command:
vxassist make vol1 1024 layout=mirror nmirror=2 mirror=ctlr
results in the mirrors being placed across the controller
groups c1, c2 and c3, c4.
da Specifies a VERITAS Volume Manager disk (VM disk) by device
name (disk access record name). For example, c2t1d0
indicates a VM disk defined on disk c2t1d0.
device (alias: d)
Specifies all VM disks on a physical disk. The physical
disk is specified in the form c#t#d#, which indicates the
controller, target ID, and disk number. Typically, only one
VM disk device is created for each physical disk.
diskrpm (alias: rpm)
Specifies disks with a given rotation speed in revolutions
per minute (for example, 7200).
dm (alias: disk)
Specifies a VM disk by disk name (disk media record name) in
the disk group of the volume. Specifying a disk class type
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of dm or disk is equivalent to giving a storage
specification with no disk class name.
enclr (alias: e, enclr, enclosure)
Specifies disks belonging to a particular enclosure. The
enclosure name is obtained using the command:
vxdmpadm listenclosure all
For example, the following command excludes disks in the
enclosure enc1 from the operation.
vxassist make vol1 1024 layout=mirror nmirror=2 \
!enclr:enc1
target (alias: t)
Specifies disks with the same SCSI target address on the
same controller. The target is specified in the form c#t#.
For example, t:c2t4 selects disks on target 4 of controller
2.
Other Attributes [Toc] [Back]
Other attributes are of the form attribute=value. The attribute name
in an attribute value pair never contains 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
cause an error indicating an unrecognized attribute.
Defined attributes (and common aliases) are:
alloc=storage-spec[,storage-spec,...]
Specifies storage as single attributes. This is useful in a
defaults file, so that all attributes (including storage
specifications) are 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.
col_switch=size1,size2[,...]
When creating a volume using ordered allocation (-o
ordered), specifies how much space to allocate from each
listed disk to a concatenated column before switching to the
next disk. The number of size arguments (switch points)
determines how many disks are concatenated to form a column.
size1 space is allocated from the first disk, size2 space is
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then allocated from the second disk, and so on. The switch
points are applied identically to all columns in the volume
being created.
For more information, see the Ordered Allocation section
below.
comment=comment
Specifies a comment to give to a volume when it is created.
This comment can be displayed with vxprint -l, and can be
changed, at a later time, with vxedit set. This attribute
can be used with the make and snapshot operations.
dcolen=number (alias: dcologlen)
Specifies the length of each plex in a DCO volume. By
default, specifying a length on the command line creates a
DCO volume. The default length is 132 blocks, and any
specified value should be an integral multiple of 33 blocks
between 33 and 2112 blocks.
diskgroup=disk-group (alias: dg)
Specifies the disk group for an operation. If a disk group
is specified in a defaults file, then 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).
excl=yes|y|on|true|no|n|off|false
Sets or clears the EXCLUSIVE flag on the volume. A volume
in exclusive open state can be opened by only one node in
the cluster at a time. Multiple opens of an exclusive volume
from the same node are permitted. Non-exclusive volumes can
be simultaneously opened by more than one node. After a
node opens an exclusive volume, every other node's open
attempt fails until the last close of the volume by the
first opener. Such an open failure returns a EBUSY error
code.
Note: Only available if the VERITAS Volume Manager cluster
feature is enabled.
fastresync=yes|y|on|true|no|n|off|false (alias: fmr)
Enables or disables both Persistent and Non_Persistent
FastResync. If enabled, FastResync is non-persistent if a
DCO object and a DCO volume are not associated with a
volume, and it is persistent if a DCO object and DCO volume
are associated with a volume.
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Note: A license is necessary to use the FastResync feature.
fstype=file-system-type
Specifies the file system type for a new volume (this is
used only with the make operation). The file system type
for a volume is usually determined when needed by running
the fstyp utility (see fstyp(1M)), but can be specified
explicitly. The file system type parameter is used with the
VERITAS Volume Manager vxresize utility, as well as with
volume snapshots, copies, and dissociates (to select
features that are used with VERITAS File System (VxFS)).
The file system type can be changed at any later time with
the vxedit set operation.
group=owning-group
Sets the group ID for a new volume. The group ID can be
specified numerically or with a system group name. This
attribute is used only with the make operation. By default,
volumes are created with group 0.
init=initialization-type
Specifies how to initialize a new volume. The default method
(which can be selected explicitly with init=default) is to
call vxvol start to perform a default initialization that is
specific to a usage type. A new volume can be left
uninitialized with init=none. The most useful non-default
initialization that can be specified is init=zero, to clear
the volume before enabling it for general use.
layout=layout
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