voldg - Manages Logical Storage Manager disk groups
/sbin/voldg init groupname {medianame=accessname} [nconfig=config-copies
| all | default] [minor=base-minor]
/sbin/voldg [-g diskgroup] [-f] reminor [diskgroup]
new-base-minor
/sbin/voldg [-tfC] [-n newname] [-o shared | private] [-o
convert_old] import diskgroup
/sbin/voldg [-n newname] [-h newhostid] deport
diskgroup...
/sbin/voldg [-g diskgroup] [-k] adddisk {medianame=accessname}
/sbin/voldg [-g diskgroup] [-k] rmdisk {medianame...}
/sbin/voldg [-q] list [diskgroup...]
/sbin/voldg [-g diskgroup] [-qa] free [medianame...]
/sbin/voldg [-g diskgroup] [-q] spare [medianame...]
/sbin/voldg flush [diskgroup...]
/sbin/voldg [-g diskgroup] [-k] repldisk unassoc-medianame=spare-medianame...
Specifies the disk group for the operation, either by name
or by disk group ID. If no disk group is specified, the
rootdg disk group is implied. Clears the previous name of
the specified disk group. Forces an operation that the
Logical Storage Manager (LSM) considers potentially dangerous
or of questionable use. This permits a limited set
of operations that would otherwise be disallowed. Some
operations might be disallowed even with this option.
Keeps (when used with rmdisk or repldisk) or reapplies
(when used with adddisk) the previous LSM disk media
records for the named disk. Typically used when replacing
a failed disk to keep the LSM structure of the affected
volume or disk group intact. This option sets any plexes
requiring recovery to STALE. Assigns a new host name to
the disk group. Assigns a new name to the disk group.
Used with import. Converts the disk group's configuration
databases and kernel change logs as appropriate for the
system on which the disk group is being imported. When
manually importing a disk group to a cluster from a standalone
system, use -o shared. When manually importing a
disk group to a standalone system from a cluster, use -o
private. Used with import to import disk groups deported
before upgrading the LSM software from pre-Version 5.0 to
Version 5.0 or higher. This option upgrades the disk
group's metadata to the current format and examines all
volumes to determine if they use Block Change Logging
(BCL). If such volumes are found, LSM displays a message
instructing you to use the vollogcnvt utility to convert
BCLs to Dirty Region Logs (DRLs). The disk group is
imported but logging is disabled on volumes that use BCL.
The volume is usable and data continues to be written to
all mirrors, but if a disk in the volume fails or the system
crashes, the entire volume will be resynchronized to
recover the data. Suppresses headers in output fields. If
used with diskgroup, this option is ignored. Displays
information about space on spare disks (which is not
really allocatable) in addition to regular free space in
the disk group. Normally, spare disk information is not
displayed. Performs the operation temporarily.
When used with import, the disk group will not be
reimported on reboot. Normally, an imported disk
group will be reimported automatically when the
system is rebooted, if at least some of the disks
in the disk group remain accessible and usable. If
you do not want the disk group to be reimported
when the system reboots, import it with the -t
option.
Can be used with -n newname to temporarily assign a
new minor number or name to a volume or disk group,
respectively. When used with -n newname when
importing a disk group, the disk group's stored
name is retained, but the disk group is known to
the new host as newname. This allows the disk
group to be reimported on the original host with
its former name.
Defines a new disk group composed of the disks identified
by disk access names. This operation assigns an internal
unique ID to the group, stores a reference to the group on
all of the named disks that have a disk header, and stores
a disk group record in the disk group's configuration
database. At least one of the disks specified must have
space allocated for a configuration copy.
If a medianame is specified for use with a particular
disk, that medianame will name the disk media
record used to reference the disk within the disk
group (for operations such as rmdisk and subdisk
creations). If no medianame is specified, the disk
media name defaults to accessname. See voldisk(8)
for more information on defining and initializing
disk access records.
The init operation can be used to initialize a root
disk group configuration, which is identified by
the special name rootdg. Disks should be initialized
and added to the disk group right after rootdg
is created.
If the autoconfiguration functionality of LSM is
disabled, add the names of disks that have copies
of the rootdg configuration database to the
/etc/vol/volboot bootstrap file. See voldctl(8).
The nconfig attribute can be used to specify the
number of configuration database copies and kernel
log copies that are maintained for a disk group.
The value of config-copies can be one of the following:
LSM maintains the copies and their number
and distribution throughout the disks and
controllers in the disk group. All configuration
and kernel log copies on all disks in the disk
group are maintained.
This policy places extra overhead on the system,
because every copy of the configuration database
must be updated with every configuration change.
The specified number of copies is maintained (or
all copies, if the number you specify is larger
than the number of available copies on all disks).
When a specific number (or default) is requested,
configuration copies are scattered approximately
evenly through the disk controllers in the disk
group. If SCSI disks with multiple disks per target
are found, each such target is treated similarly to
a controller (that is, configuration copies are
evenly distributed among such targets). With the
default policy, one configuration and log copy is
maintained for each controller, and one configuration
and log copy is also maintained for each SCSI
target that has multiple disks; if this does not
result in allocating at least four copies, additional
copies are spread through the controllers
and targets.
Note
If a policy other than all is used, some disks will
not have up-to-date, online configuration and log
copies. As a result, it is possible that some number
of disk failures will leave a disk group unusable,
even if some disks in the disk group remain
usable. However, the default policy allocates a
sufficient number of copies, in a sufficient spread
of locations, so that such a scenario is very
unlikely to occur. The default policy is the recommended
policy.
Refer to voldisk(8) for more information on configuration
and log copies and for information on how
to create them. Because disk groups can be moved
between systems, LSM lets you allocate volume
device numbers in separate ranges for each disk
group. That way, you can choose ranges such that
all disk groups in a group of machines can be moved
without causing device number collisions. Collisions
may occur because LSM stores device numbers
in disk group configurations, so that the same numbers
can be used after a reboot (which is necessary
for use with NFS, which requires persistency of
device numbers). If two systems use the same device
numbers for a set of volumes, and if a disk group
from one machine is moved to the other, LSM can be
forced to temporarily remap some devices.
A base volume device minor number can be set for a
disk group with the minor operand. Volume device
numbers for a disk group are chosen to have minor
numbers starting at this base minor number. On
Tru64 UNIX systems, minor numbers can range up
through 1048576. If no more than 1000 volumes would
ever be created in any one disk group, then 1048
different ranges of minor numbers are available for
different disk groups. A reasonably sized range
should be left at the end for temporary device
number remappings (in the event that two device
numbers still conflict).
If the minor attribute is not specified on the init
command line, LSM chooses a random number of at
least 1000 that is a multiple of 1000 and yields a
usable range of 1000 device numbers. This default
number is chosen such that it does not overlap
within a range of 1000 of any currently imported
disk groups and does not overlap any currently
allocated volume device numbers.
Note
The default policy is likely to ensure that a small
number of disk groups can be merged successfully
between a set of machines. However, in cases where
disk groups will be merged automatically using
fail-over mechanisms, you should select ranges that
avoid overlap. Changes the base minor number for a
disk group, and renumbers all devices in the disk
group to a range starting at that number. If the
device for a volume is open, the old device number
will remain in effect until the system is rebooted
or until the disk group is deported and reimported.
Also, if you close an open volume, you can execute
voldg reminor again to cause the renumbering to
take effect without rebooting or reimporting.
A new device number can also overlap with a temporary
renumbering for a volume device, which will
also require a reboot or reimport for the new
device numbering to take effect. A temporary renumbering
can happen in the following situations: When
two volumes (for example, volumes in two different
disk groups) share the same permanently assigned
device number, in which case one of the volumes is
renumbered temporarily to use an alternate device
number When the persistent device number for a volume
is changed, but the active device number cannot
be changed to match The active number can be left
unchanged after a persistent device number change
either because the volume device was open or
because the new number was in use as the active
device number for another volume.
The voldg reminor operation will fail if you try to
use a range of numbers currently in use as a persistent
(not a temporary) device number. You can
force use of the number range with the -f option.
With the -f option, some device renumberings might
not take effect until a reboot or a reimport (just
as with open volumes). Also, if you force volumes
in two disk groups to use the same device number,
one of the volumes will be temporarily renumbered
on the next reboot. The volume device to be renumbered
is selected at random, except that device
numberings in the rootdg disk group take precedence
over all others.
The -f option should be used only when swapping the
device number ranges used by two or more disk
groups. See EXAMPLES for more information. Imports
a disk group to make the specified disk group
available on the local machine. This makes any configuration
information stored with the disk group
accessible, including any disk and volume configurations.
You specify the disk group to import with
the diskgroup argument, which can be either the
administrative disk group name or the disk group's
unique ID.
Normally, a disk group is not imported if some
disks in the disk group cannot be found by the
local host. You can force the import with the -f
option if, for example, one of the disks is currently
unusable or inaccessible.
Note
Take care when using the -f option, because it can
cause the same disk group to be imported twice from
disjointed sets of disks, causing the disk group to
become inconsistent.
When a disk group is imported, all disks in the
disk group are stamped with the host's ID, which is
usually the host name. Normally, a disk group cannot
be imported if any of its disks are stamped
with a nonmatching host ID. This provides a check
in cases where disks can be accessed from more than
one host.
If you are certain that a disk is not in use by
another host (such as because a disk group was not
cleanly deported), use the -C option to clear the
existing host ID on all disks in the disk group as
part of the import. You can also clear a host ID
using the voldisk clearimport command.
You can rename a disk group on import using the -n
newname option. If you do not want the name change
to be permanent, use the -n option with the -t
option. This retains the original name of the disk
group but presents the disk group to the importing
host under the new name. Disables access to the
specified disk group. You cannot deport a disk
group if any volumes in the disk group are open.
When you deport a disk group, the host ID, which is
usually the host name, is cleared on all disks in
the disk group unless you specify a new host ID
using the -h option. This is to prevent automatically
importing the disk group when the system
reboots.
You can rename a disk group when you deport it with
the -n newname option. You can also assign the disk
group to an alternate host by specifying the host
ID (voldctl(8)) of the alternate host with the -h
newhostid option. This allows the disk group to be
automatically imported when the alternate host
reboots. See EXAMPLES. Adds the specified disk or
disks to a disk group (rootdg by default). The disk
must not already be part of an imported disk group.
The accessname component to a disk specification
argument names a disk access record (a device
address specification) used to access the disk. If
a medianame component is specified, it names the
disk media record used to define the disk within
the disk group. If no medianame component is specified,
the disk media record will have the same name
as the disk access record.
Adding a disk to a disk group causes the disk
group's configuration to be copied onto the disk
(if the disk has regions for configuration copies).
Also, the disk is stamped with the system's host
ID, which is usually the host name, as defined in
the /etc/vol/volboot file. Removes the specified
disk or disks from a disk group (rootdg by
default). The last disk cannot be removed from its
disk group. It is not possible to remove the last
disk containing a valid disk group configuration or
log copy from its disk group.
Normally, the rmdisk operation fails if subdisk
records point to the named disk media records. However,
if the -k option is specified, the disk media
records will be kept, although in a removed state,
and the subdisk records will still point to them.
The subdisks, and any plexes that refer to them,
are unusable until the disk is again added using
the -k option to the adddisk operation. Any volumes
that become unusable, because all plexes become
unusable, are disabled.
Note
Use extra care with the -k option because this
option can disable active volumes. Lists the contents
of disk groups. If no diskgroup argument is
specified, all disk groups are listed in an abbreviated
one-line format. If a diskgroup argument is
specified, a longer format is displayed indicating
the status and configuration of the disk group and
a listing of the disks that contain copies of its
configuration database and kernel log. Lists free
space that can be used for allocating subdisks. If
a disk group is specified, the output is limited to
the indicated disk group; otherwise, space is
listed from all disk groups. If disks are specified
by disk media name, the output is restricted to the
indicated disks.
A region of free space is identified by disk media
name, a physical device tag, an offset relative to
the beginning of the public region for the media,
and a length.
The physical device tag is a reference that indicates
which physical device defines the disk media.
It appears as a truncated disk access name. If a
particular physical device is split into several
Logical Storage Manager disk objects, the device
tag for each disk object will be the same. Device
tags can be compared to identify space that is on
the same or on different physical disks. Lists
spare space that can be used for relocating subdisks
during recovery. If a disk group is specified,
the output is limited to the indicated disk
group; otherwise, spare space from all disk groups
is listed. If disks are specified by disk media
name, the output is restricted to the indicated
disks.
A region of spare space is identified by disk media
name, a physical device tag, an offset relative to
the beginning of the public region for the media,
and a length.
The physical device tag is a reference that indicates
which physical device defines the disk media.
It appears as a truncated disk access name.
Rewrites all on-disk structures managed by the Logical
Storage Manager for the named disk groups.
This rewrites all disk headers, configuration
copies, and kernel log copies. Also, if any configuration
copies were disabled (for example as a
result of I/O failures), this will rewrite those
configuration copies and attempt to enable them.
Dissociates the disk access record from the disk
media record named by spare-medianame and reassociates
it with the unassociated disk media record
named by unassoc-medianame. Both unassoc-medianame
and spare-medianame must be members of the disk
group named by the diskgroup argument (rootdg by
default). However, if the -k option is specified,
the disk media records for the spare-medianame will
be kept, although in a removed state.
The voldg utility performs basic administrative operations
on disk groups. Operations include the creation of disk
groups, the addition of disks to a disk group, and disk
group imports and deports. The behavior of the voldg utility
depends upon the keyword specified as the first
operand.
A groupname argument must be a disk group name.
A diskgroup argument can be either a disk group name or a
disk group ID.
An accessname argument refers to a disk access name (also
referred to as a disk device name), as stored in the root
configuration by the voldisk utility (for example, dsk5).
A medianame argument is an administrative name used to
define a disk within a disk group (for example, disk01).
To swap the number ranges for two disk groups, use the -f
option when renumbering the first disk group to use the
range of the second disk group. Renumbering the second
disk group to the first range does not require the -f
option:
# voldg -f reminor dg-1 dg2-base-minor # voldg
reminor dg-2 dg1-base-minor To move a rootdg disk
group from one host to a second host (for example,
so you can make repairs to the root volume) and
then move the disk group back to the originating
host, which can then be rebooted on the repaired
disk group, do the following: Identify the disk
group ID for the rootdg disk group with voldisk -s
list. On the other host, use that disk group ID to
import that rootdg using -C to clear import locks,
-t for a temporary import, and -n to specify an
alternate name (to avoid collision with the rootdg
disk group on the second host):
# voldg -tC -n tempname import rootdg_id After
repair, deport the disk group using -h to restore
the first host ID:
# voldg -h orig_host_id deport tempname
To deport a disk group to be used as the rootdg
disk group for a new machine: Deport the disk
group, renaming it rootdg and assigning the new
host ID: # voldg -n rootdg -h newhostid deport
diskgroup Connect the disks to the new host. Boot
the new host. The system finds the configuration
automatically and imports the new rootdg disk
group. To import disk groups deported from a preVersion
5.0 version of LSM onto a system running
Version 5.0 or higher and upgrade their metadata
format, enter: # voldg -o convert_old import
diskgroup
If the disk group contains volumes that use BCL,
the following message is displayed:
lsm:voldg:WARNING:Logging disabled on volume. Need
to convert to DRL. lsm:voldg:WARNING:Run the vollogcnvt
command to automatically convert logging.
Commands: vold(8), voldisk(8), vollogcnvt(8), volplex(8),
volume(8)
Other: volintro(8)
voldg(8)
[ Back ] |
