# man vxdg  
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Maintenance Commands                                     vxdg(1M)

NAME
     vxdg - manage Volume Manager disk groups

SYNOPSIS
     vxdg  [ -g diskgroup ] [ -kp ] adddisk [ medianame=]
           accessname...

     vxdg  [ -n newname ] [ -h newhostid ] deport diskgroup...

     vxdg destroy   diskgroup...

     vxdg flush  [ diskgroup...]

     vxdg  [ -g diskgroup ] [ -qa ] free [ medianame...]

     vxdg  [ -Cfst ] [ -n  newname ] import diskgroup

     vxdg  [ -T version ] [ -s ]  init groupname
           [ nconfig=config-copies ] [ nlog=log-copies ]
           [ minor=base-minor ] [ medianame =] accessname...

     vxdg  [ -q ] list [ diskgroup...]

     vxdg  [ -g diskgroup ] [ -f ]  reminor
           [ diskgroup ]  new-base-minor

     vxdg [-g diskgroup ] [-k ] repldisk
           unassoc-medianame=spare-medianame...

     vxdg  [ -g diskgroup ] [ -k ] rmdisk medianame...

     vxdg  [ -g diskgroup ] [ -q ] spare [ medianame...]

     vxdg  [ -T version ]  upgrade  diskgroup

DESCRIPTION
     The vxdg 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 vxdg utility
     depends upon the keyword specified as the first operand.

     A diskgroup argument can be either a disk group  name  or  a
     disk  group ID.   A groupname argument is a disk group name,
     not a disk group ID.  An accessname  argument  refers  to  a
     system-dependent  disk  access  name  (also referred to as a
     disk device name), as stored in the  root  configuration  by
     the  vxdisk  utility.  If  the slice number extension in the
     disk access record name is not included in  the  accessname,
     s2  is  assumed  by default.  If any other slice is required
     then  it  should  be  included  in  the  accessname  (as  in
     c2t1d0s2).  A  medianame  argument is an administrative name

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     used to define a disk within a disk group.

KEYWORDS
     vxdg adddisk
               Add the specified disk(s) to a disk group  (rootdg
               by default).  The disk must not already be part of
               a disk group.  The accessname component to a  disk
               specification  argument names a disk access record
               (essentially a device address specification)  used
               to  access  the disk.  If a medianame component is
               specified, then it names  the  disk  media  record
               used to define the disk within the disk group.  If
               no medianame component is specified, then 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, as defined in the volboot file.

               If the -k flag is specified, then the  disk  media
               name  must  represent a disk media record that was
               previously dissociated from its disk access record
               with -k rmdisk; otherwise, a new disk media record
               will be created to represent the disk.   With  the
               -k  option,  plexes  requiring  recovery  will  be
               flagged as stale.

               Specifying the -p flag with  -k  packs  contiguous
               subdisks into one subdisk and aligns them consecu-
               tively on  their  respective  disks.  Use  the  -p
               option  when adding a root encapsulated disk or it
               may not boot correctly.

               In Cluster Volume Manager,  adding  a  disk  to  a
               cluster-shared disk group will fail if the disk is
               not physically accessible from all joined nodes in
               the  cluster.   If the addition is successful, the
               disk is stamped with the  cluster  ID  and  marked
               with the shared flag.

     vxdg deport
               Disable access to the  specified  disk  group.   A
               disk  group  cannot  be deported if any volumes in
               the disk group are currently open.   When  a  disk
               group is deported, the host ID stored on all disks
               in the disk group will be cleared  (unless  a  new
               host  ID  is specified with -h), so the disk group
               will not be reimported automatically when the sys-
               tem is rebooted.

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               A disk group can be renamed on deport by  specify-
               ing a new disk group name with -n newname.  A lock
               can be assigned to an alternate host by specifying
               the  host  ID  (see  vxdctl(1M))  of the alternate
               host.  This allows the  disk  group  to  be  auto-
               imported  when  the  alternate  host reboots.  For
               example, the -n and -h options can be combined  to
               export  a disk group to be used as the rootdg disk
               group for a new machine.

               In Cluster Volume Manager, when  a  cluster-shared
               disk  group is deported, the cluster ID and shared
               flag stored on all disks in  the  disk  group  are
               cleared,   so  the  disk  group  is  not  imported
               automatically when the cluster is next started.

               Trying to deport a  shared  disk  group  during  a
               cluster reconfiguration will fail.

     vxdg destroy
               Removes a diskgroup  from  the  system.  Use  this
               option  when  a  disk group and the information on
               the disks is no  longer  needed.   This  frees  up
               space  for use by other disk groups.  A disk group
               cannot be destroyed if any  volumes  in  the  disk
               group  are open.  vxdg destroy can be used only on
               imported disk groups.

     vxdg flush
               Rewrite all disk on-disk structures managed by the
               Volume  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 configura-
               tion copies and attempt to enable them.

     vxdg free List free space that can be  used  for  allocating
               subdisks.  If a disk group is specified, limit the
               output to the indicated disk group, otherwise list
               space  from  all disk groups.  If disks are speci-
               fied, by disk media name, then restrict the output
               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  indi-
               cates  which  physical  device  the  disk media is
               defined on.  It appears as a truncated disk access
               name.   If  a  particular physical device is split
               into several Volume Manager disk objects, then the

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               device  tag  for  each  Volume Manager disk object
               will be the same. Device tags can be  compared  to
               identify space that is on the same or on different
               physical disks.

               If the -q option is specified, then no  header  is
               printed  describing  output  fields.   If  the  -a
               option is specified, then  space  on  spare  disks
               (which  is  not  really  allocatable) is listed in
               addition to regular free space;  otherwise,  space
               on spare disks is not listed.

     vxdg import
               Import a disk group to  make  the  specified  disk
               group  available  on the local machine.  This will
               make any configuration information stored with the
               disk  group  accessible,  including  any  disk and
               volume configurations.  The disk group  to  import
               is  indicated by the diskgroup argument, which can
               be either an administrative disk group name  or  a
               disk group unique ID.

               Normally, a disk group will  not  be  imported  if
               some  disks  in  the disk group cannot be found by
               the local host.  The -f  option  can  be  used  to
               force  an import if, for example, one of the disks
               is currently unusable or inaccessible.

               Note: Care must be taken when using the  -f  flag,
               since  it  can  cause  the  same  disk group to be
               imported twice from disjoint sets of disks,  caus-
               ing the disk group to become inconsistent.

               When a disk group is imported, all  disks  in  the
               disk  group  are  stamped with the host's host ID.
               Normally, a disk group cannot be imported  if  any
               of  its disks are stamped with a non-matching host
               ID.  This provides a sanity check in  cases  where
               disks can be accessed from more than one host.

               If it is certain that a disk  is  not  in  use  by
               another host (such as because a disk group was not
               cleanly deported), then the -C option can be  used
               to  clear the existing host ID on all disks in the
               disk group as part of the import.  A host  ID  can
               also be cleared using vxdisk clearimport.

               A new name can be  given  to  the  disk  group  on
               import  using  -n newname.  If -n is used with the
               -t option, then the stored name of the disk  group
               will  remain unchanged, but the disk group will be
               known to the importing host under  the  new  name;

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               otherwise, the name change will be permanent.

               Normally, an imported disk  group  will  be  reim-
               ported  automatically when the system is rebooted,
               if at least some of the disks in  the  disk  group
               remain  accessible  and  usable.  This can be dis-
               abled using the -t option, which causes the import
               to   be   persistent  only  until  the  system  is
               rebooted.

               As an example of the use of -n and  -t,  a  rootdg
               disk  group  from  one  host  can be imported on a
               second host, operations can be  performed  on  the
               second  host  (such  as making repairs to the root
               volume), and the disk group can be given  back  to
               the  originating  host, which can then be rebooted
               on the repaired disk group.  To do this,  identify
               the  disk  group ID for the rootdg disk group with
               vxdisk -s list, and use that disk group to  import
               that rootdg using -C to clear import locks, -t for
               a temporary name, and -n to specify  an  alternate
               name  (to  avoid  collision  with  the rootdg disk
               group on the second host).  After  repair,  deport
               the  disk  group  using  -h  (described  below) to
               restore the import lock from the first host.

               In Cluster Volume Manager, use the  -s  option  to
               import  a disk group as cluster-shareable. This is
               only valid if the cluster is active  on  the  host
               where the import takes place.  Ensure that all the
               disks in a shared disk group are physically acces-
               sible  by  all  hosts.  A host which cannot access
               all the disks in a shared disk group  cannot  join
               the cluster.

               The disks in a shared disk group are stamped  with
               the  ID  of  the cluster to which the hosts belong
               and are marked with the shared flag.  When a  host
               joins  a  cluster,  it  automatically imports disk
               groups whose disks are stamped  with  the  cluster
               ID.

               Trying to import a  shared  disk  group  during  a
               cluster reconfiguration will fail.

     vxdg init Define a new disk group composed of the  indicated
               disks,  identified  by  disk  access  names.  This
               involves assigning an internal unique  ID  to  the
               group, storing a pointer to that group in the root
               configuration, storing a reference to the group on
               all  of  the  named disks that have a disk header,
               and storing  a  disk  group  record  in  the  disk

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               group's  configuration  database.  At least one of
               the disks specified must have space allocated  for
               a configuration copy.

               The init cannot complete if a disk is  being  used
               by  a  disk group, deported or otherwise.  If vxdg
               finds an unneeded disk group on the disk,  it  can
               be  cleaned  with the vxdisk -f init command. vxdg
               init can then be run again.

               If a medianame is specified for use with a partic-
               ular  disk, then that medianame will name the disk
               media record used to reference the disk within the
               disk group (for operations such as rmdisk and sub-
               disk creations).  If no  medianame  is  specified,
               then  the  disk media name defaults to accessname.
               See vxdisk(1M) for a discussion of definition  and
               initialization of disk access records.

               The init operation can be  used  to  initialize  a
               root disk group configuration, which is identified
               by the special name rootdg.  If any database loca-
               tions  are  listed  in the volboot file, then as a
               special case  for  initializing  rootdg,  no  disk
               specifications  are allowed.  Disks should be ini-
               tialized and added to the disk group as the  first
               operations  after  creating  rootdg.   Some or all
               disks added to the rootdg disk group  should  also
               be  added  to  the  volboot  bootstrap  file  (see
               vxdctl(1M)).

               The nconfig and nlog operands can be used to  con-
               figure the number of configuration database copies
               and kernel log copies that are  maintained  for  a
               disk  group.   The  config-copies  and  log-copies
               values are either a decimal number (including 0 or
               -1)  or  set to all or default.  A value of all or
               -1 signifies that all configuration or log  copies
               on all disks in the disk group will be maintained.
               A value of default or 0 (this is also the  default
               value)  signifies  that  the  Volume  Manager will
               manage copies that are distributed in a reasonable
               pattern  throughout  the  disks and controllers on
               the system.  Any other  number  signifies  that  a
               particular  number  of copies should be maintained
               (or all copies, if that number is larger than  the
               number of available configuration or log copies on
               all disks).

               When a specific number (or default) is  requested,
               configuration  copies  are scattered approximately
               evenly through the disk controllers on the system.

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               If  SCSI  disks with multiple disks per target are
               found, then each such target is treated  similarly
               to a controller (that is, configuration copies are
               evenly distributed between  such  targets).   With
               the  default policy, one configuration or log copy
               is maintained for each controller, and one  confi-
               guration  or  log copy is also maintained for each
               SCSI target that has multiple disks; if this  does
               not  result  in allocating at least 4 copies, then
               additional copies are spread through the controll-
               ers and targets.

               Refer to vxdisk(1M) for more information on confi-
               guration  and  log  copies, and for information on
               how to create them.

               Note: If a policy other than  all  is  used,  then
               some disks will not have up-to-date, online confi-
               guration and log copies.  As a result, it is  pos-
               sible that some number of disk failures will leave
               a disk group unusable, even if some disks  in  the
               disk  group  remain  usable.   The  default policy
               allocates a sufficient number of copies, in a suf-
               ficient  spread of locations, that such a scenario
               is very unlikely to occur.

               Since disk groups can be moved between systems, it
               is  desirable that device numbers used for volumes
               be allocated in  separate  ranges  for  each  disk
               group.   That  way,  an  administrator  can choose
               ranges such that all disk groups  in  a  group  of
               machines  can be moved around without causing dev-
               ice  number  collisions.  Collisions   may   occur
               because  the  Volume Manager 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  per-
               sistency  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, then the Volume Manager may  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 will be  chosen  to  have
               minor  numbers starting at this base minor number.
               Minor numbers can range up to 131071, so if it  is
               presumed that no more than 1000 volumes would ever
               be created in any one disk  group,  131  different
               ranges  of  minor  numbers  are available for dif-
               ferent disk  groups.   A  reasonably  sized  range

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               should  be  left  at  the end for temporary device
               number remappings (in the event  that  two  device
               numbers still conflict).

               If no minor operand is specified on the init  com-
               mand  line, then the Volume Manager chooses a ran-
               dom 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 over-
               lap any currently allocated volume device numbers.

               Note: The default policy is likely to ensure  that
               a  small  number of disk groups can be merged suc-
               cessfully between a set of machines.  However,  in
               cases  where  disk groups will be merged automati-
               cally using fail-over mechanisms, the  administra-
               tor  should  select ranges that are known to avoid
               overlap.

               In Cluster Volume Manager, the -s option defines a
               new  disk  group  which is cluster-shareable while
               the cluster is active.  It is  the  responsibility
               of  the  user  to  ensure  that disks specified as
               members of a cluster-shareable disk group are phy-
               sically accessible from the hosts that make up the
               cluster.

               The disks in a shared disk group are stamped  with
               the  ID  of  the cluster to which the hosts belong
               and are marked with the shared flag.  When a  host
               joins  a  cluster,  it  automatically imports disk
               groups whose disks are stamped  with  the  cluster
               ID.

               Trying to create a  shared  disk  group  during  a
               cluster reconfiguration will fail.

               Note: Volumes in shared disk groups must have  the
               same minor number on all nodes in the cluster.  If
               there is a conflict when a node attempts  to  join
               the  cluster,  the  join will fail.  In that case,
               the administrator should use the reminor operation
               on the joined node(s) to resolve the conflict.  In
               a cluster where more than one node is joined,  the
               administrator should use a base minor number which
               does not conflict on any node.

               If a version is specified with the -T option,  the
               diskgroup  is initialized with that diskgroup ver-
               sion. This  limits  the  operations  that  can  be

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               performed  and  features that can be used to those
               supported by the specified diskgroup version. This
               makes  the  diskgroup  compatible with releases of
               VxVM that support that version. If no  version  is
               specified,  the  diskgroup is initialized with the
               highest versions supported by the release of  VxVM
               currently  running  on  the  system.  See the vxdg
               upgrade operation for more information.

     vxdg list List the contents of disk groups.  If no diskgroup
               arguments  are specified, then all disk groups are
               listed in  an  abbreviated  one-line  format.   If
               diskgroup  arguments  are specified, then a longer
               format is used to indicate the status of the  disk
               group,  and of the specified disk group configura-
               tion.

               If the -q option is specified, then no  header  is
               printed describing output fields.  This option has
               no effect with the  long  formats  generated  with
               diskgroup arguments.

               In Cluster Volume Manager, if  the  -s  option  is
               specified,  all  cluster-shared  disk  groups  are
               listed in a one-line format.  If  diskgroup  argu-
               ments are specified, -s has no effect.

     vxdg reminor
               Change the base minor number for a disk group, and
               renumber  all devices in the disk group to a range
               starting at that number.   If  the  device  for  a
               volume  is  open,  then the old device number will
               remain in effect until the system is  rebooted  or
               until  the disk group is deported and re-imported.
               Also, if you close an open volume, then  the  user
               can   execute  vxdg reminor  again  to  cause  the
               renumbering to take effect  without  rebooting  or
               reimporting.

               A new device number may also overlap with  a  tem-
               porary renumbering for a volume device, which will
               also require a reboot or reimport for the new dev-
               ice   numbering   to  take  effect.   A  temporary
               renumbering can happen  in  the  following  situa-
               tions:  when  two volumes (for example, volumes in
               two different disk groups)  share  the  same  per-
               manently assigned device number, in which case one
               of the volumes is renumbered temporarily to use an
               alternate  device  number;  or when the persistent
               device number for a volume was  changed,  but  the
               active  device  number  could  not  be  changed to
               match.  The active number may  be  left  unchanged

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               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.

               vxdg will fail if  you  try  to  use  a  range  of
               numbers  that  is currently in use as a persistent
               (not a temporary) device number.   You  can  force
               use of the number range with use of the -f option.
               With -f, some device  renumberings  may  not  take
               effect until a reboot or a re-import (just as with
               open volumes).  Also, if you force volumes in  two
               disk  groups  to  use the same device number, then
               one of the volumes will be temporarily  renumbered
               on  the  next reboot.  Which volume device will be
               renumbered should  be  considered  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.  To swap the number ranges  for  two  disk
               groups,  you  would  use  -f  when renumbering the
               first disk group to use the range  of  the  second
               disk  group.  Renumbering the second disk group to
               the first range will not require use of -f.

     vxdg repldisk
               Dissociate the DA record from the DM record  named
               by  spare-medianame  and  reassociate  it with the
               unassociated  DM   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 flag  is  specified,  then  the
               disk media records for the spare-medianame will be
               kept, although in a removed state.

     vxdg rmdisk
               Remove the specified disk(s)  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 will fail  if  sub-
               disk   records  point  to  the  named  disk  media
               records.  However, if the -k  flag  is  specified,
               then 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

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               that refer to them, will  be  unusable  until  the
               disk  is  re-added  using  the  -k  option  to the
               adddisk operation.  Any volumes that become  unus-
               able,  because all plexes become unusable, will be
               disabled.

     vxdg spare
               List spare space that can be used  for  relocating
               subdisks  during  recovery.  If  a  disk  group is
               specified, limit the output to the indicated  disk
               group,  otherwise  list  spare space from all disk
               groups.  If disks are  specified,  by  disk  media
               name,  then  restrict  the output 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  indi-
               cates  which  physical  device  the  disk media is
               defined on.  It appears as a truncated disk access
               name.

               If the -q option is specified, then no  header  is
               printed describing output fields.

     vxdg upgrade
               Upgrades the disk group to the lastest  VxVM  ver-
               sion. By default, the diskgroup version is updated
               to the running version  of  VxVM.  The  -T  option
               upgrades  the  diskgroup  to  a specified version.
               The following section lists  each  diskgroup  ver-
               sion,  the  features  it  supports,  and  the VxVM
               release that introduced it.

               10   Supports only the most basic  volume  manage-
                    ment  features of mirroring and simple strip-
                    ing.  This  format  was  introduced  in  VxVM
                    Release  1.2. Starting with VxVM Release 3.0,
                    diskgroups of version 10 can be imported, but
                    no operations can be performed on the objects
                    it contains (for example, starting volumes or
                    adding mirrors). The only operation supported
                    is  to  upgrade  the  diskgroup  to  a  later
                    release.

               20   Introduced support for RAID-5  Volumes,  new-
                    style  stripes, recovery checkpointing, disk-
                    group configuration/klog copy  limiting,  and
                    Dirty Region Logging. This version was intro-
                    duced in VxVM Release 2.0 and is supported by
                    all subsequent releases of VxVM.

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               30   Enabled support for  the  Oracle  Resilvering
                    Interface.  This  version  was  introduced in
                    VxVM Release 2.2 and is supported by all sub-
                    sequent releases of VxVM.

               40   Support for  Hot  Relocation.  Introduced  in
                    VxVM Release 2.3 and is supported by all sub-
                    sequent releases of VxVM.

               60   Support for Online Relayout, safe RAID-5 sub-
                    disk   moves,  Striped  Mirrors,  and  RAID-5
                    Snapshots. Introduced in Release 3.0.

                    You can determine a disk group version  using
                    the  vxprint  -l command, and the vxdisk list
                    operation prints a long listing  of  a  disk-
                    group.

SEE ALSO
     vxconfigd(1M),    vxdctl(1M),    vxdisk(1M),    vxintro(1M),
     vxplex(1M), vxprint(1M), vxvol(1M)

VxVM 3.0            Last change: 11 Dec 1998                   12

#  

