volsd - Perform Logical Storage Manager operations on subdisks
/sbin/volsd [-Vf] [-g diskgroup] [-U usetype] [-o useopt]
[-v volume] [-l offset] assoc plex subdisk...
/sbin/volsd [-Vf] [-g diskgroup] [-U usetype] [-o useopt]
[-v volume] [-l[column/] offset] assoc plex subdisk[:[column/]
offset]...
/sbin/volsd [-Vf] [-g diskgroup] [-U usetype] [-o useopt]
[-v volume] asfpa plex subdisk
/sbin/volsd [-Vf] [-g diskgroup] [-U usetype] [-o useopt]
[-v volume] aslog plex subdisk
/sbin/volsd [-Vf] [-g diskgroup] [-U usetype] [-o useopt]
[-v volume] [-p plex] dis subdisk...
/sbin/volsd [-Vf] [-g diskgroup] [-U usetype] [-o useopt]
[-v volume] [-p plex] [-s size] split subdisk newsd
[newsd2]
/sbin/volsd [-Vf] [-g diskgroup] [-U usetype] [-o useopt]
[-v volume] [-p plex] join sd1 sd2... newsd
/sbin/volsd [-Vf] [-g diskgroup] [-U usetype] [-o useopt]
[-v volume] [-p plex] mv oldsd newsd [newsd...]
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 name operands. Limits the operation
to apply to this usage type. Attempts to affect volumes
with a different usage type will fail. Passes in
usage-type-specific options to the operation. The following
operations are implemented by all usage types: Reduces
the system performance impact of copy operations. Copy
operations are usually performed sequentially on small
regions of the volume (normally from 16 kilobytes to 256
kilobytes). This option inserts a delay between the recovery
of each such region. You can specify a delay in milliseconds
or use the default (typically 250 milliseconds).
Changes the copy region size to the length specified 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 processes using the volume. The
default I/O size is 256 kilobytes. Removes the subdisks
after successful completion of a volsd dis operation.
Removes the source subdisk after successful completion of
volsd mv. Writes a list of utilities that would be called
from volsd, along with the arguments that would be passed.
The -V performs a "mock run" so the utilities are not
actually called. Used with the volsd split operation.
Specifies the size for the first new subdisk that will
result from splitting a subdisk. The other subdisk's size
will be the remainder of the original. This option takes a
standard Logical Storage Manager length number (see
volintro(8)). Specifies the offset of a subdisk within a
plex address space for the volsd assoc operation. For
striped plexes, a column number may be optionally specified.
If one number is given for striped plexes, the number
is interpreted as a column number and the subdisk is
associated at the end of the column. The offset is a standard
Logical Storage Manager length number (see volintro(8)). Requires that a named plex be associated with
this volume, or that a named subdisk (source subdisk for
volsd split, join, and mv operations) be associated with a
plex that is associated with this volume. Requires that a
named subdisk (source subdisk for volsd split, join, and
mv operations) be associated with this plex. Forces an
operation that the Logical Storage Manager considers
potentially dangerous or of questionable use. This permits
a limited set of operations that would otherwise be disallowed.
Some operations may be disallowed even with this
flag.
The volsd utility performs Logical Storage Manager operations
on subdisks and on plex-and-subdisk combinations.
The first operand is a keyword that determines the specific
operation to perform. The remaining operands specify
the configuration objects to which the operation is to be
applied.
Each operation can be applied to only one disk group at a
time, due to internal implementation constraints. Any plex
or subdisk name operands will be used to determine a
default disk group, according to the standard disk group
selection rules described in volintro(8). You can specify
a disk group with -g diskgroup.
If a volsd operation is interrupted by a signal, an
attempt is made to restore the disk group configuration to
a state that is roughly equivalent to its original state.
If this attempt is interrupted, such as through another
signal, you may need to perform some cleanup. The specific
cleanup actions needed are written to the standard error
before volsd exits.
Associates each named subdisk operand with the specified
plex. The first form applies to concatenated plexes
(plexes with a layout of concat). Specify the offset
within the plex for the association with -l, which takes a
standard Logical Storage Manager length number (see volintro(8)). If no offset is specified, the default is to
associate the subdisk at the end of the plex, thus extending
the length of the plex by the length of the new subdisk.
For striped plexes, a column number for the subdisk
association may be specified. The offset is interpreted
as the column offset for the subdisk. If
only one number is specified with -l for striped
plexes, the number is interpreted as a column number
and the subdisk is associated at the end of the
column.
You can specify the column or column/offset at
which a subdisk to associate the subdisk as part of
its name, in the same way you can specify subdisk
associations when creating a plex with volmake (see
volmake(4)). When specifying multiple subdisks, if
no column or column/offset is specified for a subdisk,
it is associated after the previous subdisk.
A subdisk cannot be associated to overlap with an
another associated subdisk in the same plex.
If the named plex is associated with a volume, the
rules for performing the operation depend upon the
usage type of the volume. A subdisk cannot be associated
to a plex unless the putil0 field for the
subdisk is empty. Creating a subdisk with the
putil0 field set to a nonempty value is a sufficient
means of ensuring that no Logical Storage
Manager operation will write to the region of disk
blocks allocated to the subdisk because the subdisk
cannot be associated through any means to a plex,
and because subdisks cannot be used directly to
read from or write to a disk. Associates the named
subdisk with the named plex as a log area for the
plex. At most, one log subdisk can be associated
with a plex at any given time. Currently, log subdisks
can be used only with the dirty region logging
feature, as defined by the DRL volume logging
type. If the named plex is associated with a volume,
the rules for performing the operation depend
upon the usage type of the volume. A subdisk cannot
be associated if the putil0 field is set on the
subdisk, just as with volsd assoc. Associates the
named subdisk with the named plex as an FPA log
subdisk for the plex. At most, one FPA log subdisk
can be associated with a plex at any given time. If
the named plex is associated with a volume, volsd
verifies that the plex is eligible to be an FPA
plex before it completes the association. Dissociates
each specified subdisk from the plex that it
is associated with. If a subdisk is associated
(through its plex) with a volume, the rules for
performing the operation depend upon the usage type
of the volume.
Subdisk dissociation can be used as part of tearing
down a plex, or as part of reorganizing disk space
usage. Typically, the subdisk is no longer needed
after dissociation. To support this you can use the
-o rm option to remove the named subdisks after
successful dissociation. Splits the subdisk subdisk
into two subdisks that reside on the same section
of the same device, and that have contiguous
or striped plex associations (if the named subdisk
is associated). The first of the two resultant subdisks
will have a length of size, which is a standard
Logical Storage Manager length number (see
volintro(8)), and the second subdisk will take up
the remainder of the space used by the original
subdisk.
If both newsd and newsd2 are specified, the resultant
subdisks are newsd and newsd2. If no newsd2
operand was specified, the resultant subdisks are
named subdisk and newsd.
If the named subdisk is associated with an associated
plex, the rules for performing the operation
depend upon the usage type of the volume. Log subdisks
and FPA subdisks cannot be split. Joins the
subdisks named by the sd operands to form a new
subdisk named newsd. The sd operands must specify
subdisks that represent contiguous sections of the
same device, and of the same plex (if they are
associated). For a striped plex, the sd operands
must be in the same column. At least two sd
operands are required. At the end of the operation,
the sd configuration objects are removed. The newsd
operand can have the same name as one of the sd
operands, or it can have a different name.
If the sd operands are associated with an associated
plex, the rules for performing the operation
depend upon the usage type of the volume. Moves
the contents of oldsd onto the new subdisks and
replaces oldsd with the new subdisks for any associations.
If multiple new subdisks are specified,
they are associated starting where the old subdisk
began and placed consecutively with no space
between them. The operation requires that oldsd be
associated with an associated plex and that all new
subdisks are not already associated to any plex.
You can use this operation on a subdisk that is
used by an active volume; LSM ensures that data is
copied and associations are changed without loss or
corruption of data. The rules for performing the
operation depend upon the usage type of the volume.
Moving a subdisk is the normal means of reorganizing
disk space. For example, move regions of disk
used by one volume to another disk to reduce contention
on the original disk. Typically, once the
operation completes, the original subdisk is no
longer needed and can be removed. To support this,
you can use the -o rm option to remove oldsd after
successful completion of the operation.
FSGEN AND GEN USAGE TYPES [Toc] [Back] The fsgen and gen usage types provide identical semantics
for all operations of the volsd utility.
In addition to the standard -o options supported for all
usage types, the fsgen and gen usage types provide the
following additional option: Forces an operation that the
Logical Storage Manager considers potentially dangerous or
of questionable use. This applies to attempts to dissociate
subdisks (making a plex sparse) and to attempts to
move subdisks onto subdisks that have a different size.
This flag is the same as -f.
Limitations and extensions for the fsgen and gen usage
types consist of the following: If the named plex is
enabled, and is associated with an enabled plex, the named
plex must be ACTIVE or EMPTY. Subdisks can be associated
with a nonenabled plex only if the utility state of the
plex is EMPTY, STALE, or OFFLINE, or if the plex is CLEAN
and no other plexes associated with the volume are CLEAN
or ACTIVE.
If the subdisk is associated with a nonenabled
plex, or if it is associated with the only enabled,
read-write plex in a volume, the operation completes
without copying any data onto the subdisk.
If the subdisk is associated with an enabled plex
in a mirrored volume, the operation may have to
copy data from the volume onto the new subdisk
before the operation can complete. If a log
subdisk is associated with a plex that is associated
with a volume that has a logging type of
UNDEF, the logging type of the volume is converted
to DRL. Logging of volume changes is not enabled
until there are at least two read-write mode plexes
attached to the volume. Dissociating a subdisk
requires the use of -f if it would cause an enabled
plex in an enabled volume to become sparse relative
to the volume. Even with -f, it is not possible to
make two plexes sparse if no complete, enabled,
read-write plexes would remain associated. For disabled
volumes, a similar check is made with respect
to ACTIVE and CLEAN plexes. The fsgen and gen
usage types apply no additional restrictions and
add no extensions to the split and join operations.
If the total size of the destination subdisks differs
from that of the source subdisk, the -f option
must be specified. The operation still fails if the
total size of the destination subdisks is larger
than the source subdisk and if the address range of
any destination subdisk would conflict with another
subdisk that is associated with the plex. The total
size of the destination subdisks cannot be larger
than the source subdisk if the kernel state of the
volume or plex is detached.
The operation fails if the total size of the destination
subdisks is smaller than the source subdisk
and the operation would cause the total number of
complete, enabled, read-mode plexes in the volume
to drop to zero, while leaving more than one
sparse, enabled, read-write plex.
In addition to the standard -o options supported for all
usage types, the raid5 usage type provides the following
additional options: Forces an operation that the Logical
Storage Manager considers potentially dangerous or of
questionable use. This applies to attempts to move a subdisk
in a RAID 5 data plex if the volume the plex is associated
with does not have a log plex. This flag is the
same as -f.
The raid5 usage type supports the following keywords:
Associates the named subdisks with the named RAID 5 plex.
If the plex is enabled and is associated with an enabled
volume, any data that maps onto the subdisk will be regenerated
from the other columns of the RAID 5 plex. This is
done by marking the subdisk as stale and writeonly, regenerating
the data via VOL_R5_RECOVER ioctls, and then turning
off the stale and writeonly flags.
If the RAID 5 plex is not associated or the RAID 5
volume is not ENABLED, the subdisk is associated
and marked as stale. The subdisk's contents will be
recovered when the volume is started.
The assoc operation cannot be used on a log plex.
Dissociates the named subdisks from the named RAID
5 plex. If removing the subdisk would make the volume
unusable (because other subdisks in other
columns at the same altitude are unusable or missing)
and the volume is not disabled and EMPTY, the
operation is not allowed. If the volume is disabled
and nonEMPTY the operation requires use of -f.
The dis operation cannot be used on a log plex.
The raid5 usage type applies no additional restrictions
and adds no extensions to the split and join
operations. These operations may not be used on a
log plex. If the old subdisk is associated with a
RAID 5 plex that is associated to a RAID 5 volume,
the volume must be enabled for the move operation
to complete. The mv operation is not allowed if the
volume has stale parity or has missing or stale
subdisks at the same altitude as the subdisk being
replaced.
The mv operation first dissociates the old subdisk
and then associates the new subdisk in its place.
It then recovers the data using VOL_R5_RECOVER
ioctls, as is done for the assoc operation. If the
RAID 5 volume has no valid logs, the operation
requires use of -f. This is necessary because if a
crash were to occur while the data on the new subdisks
was being recovered, the parity could become
stale while some of the new subdisks are marked
stale, thus rendering the volume unusable.
The mv operation may be used on a log plex. The
same rules that apply to the fsgen and gen usage
type plexes apply to log plexes. The force or -f
must be used to make a log plex sparse.
Note that there is no aslog or asfpa operation for the
raid5 usage type. Logging is done on a plex level and
therefore volsd aslog is not needed, and FPA does not
apply to RAID 5 volumes by design. You associate log
plexes with RAID 5 volumes using the volplex att command.
The volsd utility 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 prevented further execution
of the utility. See volintro(8) for a list of standard
exit codes.
The utility that performs volsd operations for a particular
volume usage type.
volintro(8), volplex(8), volsd(8), volume(8)
volsd(8)
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