vgcreate(8) - NetBSD Manual Pages

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VGCREATE(8)                                                        VGCREATE(8)




NAME

       vgcreate - create a volume group


SYNOPSIS

       vgcreate  [--addtag  Tag]  [--alloc  AllocationPolicy] [-A|--autobackup
       {y|n}] [-c|--clustered {y|n}] [-d|--debug]  [-h|--help]  [-l|--maxlogi-
       calvolumes  MaxLogicalVolumes]  [-M|--metadatatypetype] [-p|--maxphysi-
       calvolumes MaxPhysicalVolumes] [-s|--physicalextentsize PhysicalExtent-
       Size[kKmMgGtT]]  [-t|--test] [-v|--verbose] [--version] VolumeGroupName
       PhysicalVolumePath [PhysicalVolumePath...]


DESCRIPTION

       vgcreate creates a new volume group called  VolumeGroupName  using  the
       block  special  device PhysicalVolumePath previously configured for LVM
       with pvcreate(8).


OPTIONS

       See lvm for common options.

       -c, --clustered {y|n}
              If clustered locking is enabled, this defaults to  y  indicating
              that  this  Volume Group is shared with other nodes in the clus-
              ter.

              If the new Volume Group contains only local disks that  are  not
              visible  on the other nodes, you must specify --clustered n.  If
              the cluster infrastructure is unavailable on a  particular  node
              at  a  particular time, you may still be able to use such Volume
              Groups.

       -l, --maxlogicalvolumes MaxLogicalVolumes
              Sets the maximum number of logical volumes allowed in this  vol-
              ume  group.  The setting can be changed with vgchange.  For vol-
              ume groups with metadata in lvm1 format, the limit  and  default
              value  is  255.   If  the metadata uses lvm2 format, the default
              value is 0 which removes this  restriction:  there  is  then  no
              limit.

       -p, --maxphysicalvolumes MaxPhysicalVolumes
              Sets  the  maximum number of physical volumes that can belong to
              this volume group.  The setting can be  changed  with  vgchange.
              For  volume  groups  with metadata in lvm1 format, the limit and
              default value is 255.  If the metadata  uses  lvm2  format,  the
              default value is 0 which removes this restriction: there is then
              no limit.  If you have a large number of physical volumes  in  a
              volume  group with metadata in lvm2 format, for tool performance
              reasons, you should consider some use of --metadatacopies  0  as
              described in pvcreate(8).

       -s, --physicalextentsize PhysicalExtentSize[kKmMgGtT]
              Sets the physical extent size on physical volumes of this volume
              group.  A size suffix (k for kilobytes up to t for terabytes) is
              optional, megabytes is the default if no suffix is present.  The
              default is 4 MB and it must be at least 1 KB and a power of 2.

              Once this value has been set, it is difficult to change it with-
              out  recreating  the volume group which would involve backing up
              and restoring data on  any  logical  volumes.   However,  if  no
              extents  need  moving  for  the  new  value  to apply, it can be
              altered using vgchange -s.

              If the volume group metadata uses lvm1 format, extents can  vary
              in  size  from 8KB to 16GB and there is a limit of 65534 extents
              in each logical volume.  The default of 4 MB leads to a  maximum
              logical volume size of around 256GB.

              If the volume group metadata uses lvm2 format those restrictions
              do not apply, but having a large number  of  extents  will  slow
              down the tools but have no impact on I/O performance to the log-
              ical volume.  The smallest PE is 1KB.

              The 2.4 kernel has a limitation of 2TB per block device.


EXAMPLES

       To  create  a  volume  group  named  test_vg  using  physical   volumes
       /dev/hdk1, and /dev/hdl1 with default physical extent size of 4MB:

            vgcreate test_vg /dev/sdk1 /dev/sdl1



SEE ALSO

       lvm(8),  pvdisplay(8),  pvcreate(8),  vgdisplay(8),  vgextend(8), vgre-
       duce(8), lvcreate(8), lvdisplay(8), lvextend(8), lvreduce(8)



Sistina Software UK    LVM TOOLS 2.02.44-cvs (02-17-09)            VGCREATE(8)