Before assigning a physical volume to a volume group, the physical volume has to be created using the pvcreate command (see pvcreate (1M)).

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1 NAME vgcreate - create LVM volume group SYNOPSIS /usr/sbin/vgcreate [-V 1.0] [-f] [-A autobackup ] [-x extensibility] [-e max_pe] [-l max_lv] [-p max_pv] [-s pe_size ] [-g pvg_name ] vg_name pv_path... /usr/sbin/vgcreate -V 2.n -s pe_size -S vg_size [-A autobackup ] [-x extensibility] [-g pvg_name ] vg_name pv_path... /usr/sbin/vgcreate -V 2.2 -s pe_size -S vg_size [-A autobackup ] [-x extensibility] [-g pvg_name ] [-U unshare_unit ] vg_name pv_path... /usr/sbin/vgcreate -V 2.n -E {-s pe_size -S vg_size} DESCRIPTION The vgcreate command without the -E option creates a new volume group, as shown by the first three forms in SYNOPSIS above. vg_name is a symbolic name for the volume group and must be used in all references to it. vg_name is the path to a directory entry under /dev that must contain a character special file named group. Except for the group entry, the vg_name directory should be empty. A user may explicitly create the vg_name directory and the group file before creating the volume group. If absent, the vgcreate command will automatically create the directory and the group file, assigning the minor number. If the group file is automatically created, any available minor number may be assigned to the group file. vgcreate leaves the volume group in an active state. Before assigning a physical volume to a volume group, the physical volume has to be created using the pvcreate command (see pvcreate (1M)). If vgcreate fails to install the first specified physical volume into the volume group, the volume group is not created. If, for any reason, one of the remaining specified physical volumes cannot be installed into the volume group, an error message is printed, but the installation continues until the end of the list of physical volumes. The vgcreate command with the -E option displays information which may be useful in deciding on parameters for use in creating a volume group version 2.0 and higher. The -E option (only for volume groups versions 2.0 and higher) displays the relationship between physical extent size (pe_size ) and maximum volume group size (vg_size). See lvm(7) for more on this topic. A pe_size or a vg_size must be supplied on the command line. If pe_size is specified, then the maximum volume group size which can be created using that extent size is displayed using the suffix notation explained in the description of the -S option. If the vg_size is specified then the minimum extent size required to support the given maximum volume group size is displayed in megabytes. Options and Arguments vgcreate recognizes the following options and arguments: -V vg_version Specify the version of the volume group. Currently only 1.0, 2.0, 2.1, and 2.2 are supported. Different versions represent significant changes in LVM software and data layout and may have compatibility implications when volume groups are shared or moved from system to system. See lvm(7) for more details. The default version is 1.0. pv_path The block device path name of a physical volume that will be assigned to the new volume group. On PA-RISC systems, pv_path should be the path name for the whole disk. For HP Integrity system boot physical volumes, pv_path should be the path name for the disk section containing the HP-UX partition (see model(1) and getconf (1)). For HP Integrity system non-boot physical volumes, pv_path can be the path name for the whole disk or the disk section containing the HP-UX partition. You can specify physical volume links pv-links for a physical volume providing different paths that reference the same physical volume in the pv_path list. HP-UX 11i Version 3: September Hewlett-Packard Company 1

2 The order in which the paths are listed is important. The first path becomes the primary link to the physical volume, and the second becomes an alternate link to the physical volume. The primary link is the default path used to access the physical volume. (see WARNINGS section). If the primary link becomes unavailable, LVM automatically switches to the alternate link to access the physical volume. Currently, LVM supports a maximum of 8 paths to a physical volume (7 alternate and one primary). vg_name The path name of a subdirectory of the /dev directory. vg_name must be empty except for a character special file named group. Typically, this directory name is in the form /dev/vgnn, where NN numbers sequentially from 00. -A autobackup Set automatic backup for this invocation of this command. autobackup can have one of the following values: y Automatically back up configuration changes made to the volume group. This is the default. After this command executes, the vgcfgbackup command (see vgcfgbackup (1M)) is executed for the volume group. n Do not back up configuration changes this time. -e max_pe Only applicable to volume groups version 1.0. Set the maximum number of physical extents that can be allocated from any of the physical volumes in the volume group. The default value for max_pe is However, if the size of any physical volume exceeds 1016 times the pe_size, the default value for max_pe is adjusted to match the physical volume size. The maximum number of physical extents can be a value in the range 1 to f Only applicable to volume groups version 1.0. This option will force a volume group to be created with a physical volume which has alternate block(s) already allocated, (that is, this physical volume was not initialized using pvcreate -f.) This option should be used with extreme caution. If the volume group to be created has a different physical extent size, the alternate block(s) might be inside the user data area. Potential data corruption could occur. -g pvg_name Create a new physical volume group with the name pvg_name. All physical volumes specified in the pv_path parameter become a member of the newly created physical volume group. The physical volume group information is stored in an ASCII file, /etc/lvmpvg. The file can be edited to create a physical volume group instead of using the vgcreate command. However, ensure that the physical volumes to be used have already been installed in the volume group prior to creating the physical volume group. The physical volume group name must be unique within a volume group although identical physical volume group names can appear in different volume groups (see lvmpvg(4) for format details). -l max_lv Only applicable to volume groups version 1.0. Set the maximum number of logical volumes that the volume group is allowed to contain. The default value for max_lv is 255. The maximum number of logical volumes can be a value in the range 1 to p max_pv Only applicable to volume groups version 1.0. Set the maximum number of physical volumes that the volume group is allowed to contain. The default value for max_pv is 16. The maximum number of physical volumes can be a value in the range 1 to s pe_size Sets the number of megabytes in each physical extent, where pe_size is expressed in units of megabytes (MB) in the range 1 to 256. pe_size must be equal to a power of 2 (1, 2, 4, 8, etc.). The default value for pe_size is 4 (four megabytes) for volume groups version Hewlett-Packard Company 2 HP-UX 11i Version 3: September 2010

3 For volume groups versions 2.0 and higher, this is a required parameter. See lvm(7) for more information on extent sizes on volume groups versions 2.0 and higher. -S vg_size Only applicable to volume groups versions 2.0 and higher. Sets the maximum size of the volume group. The maximum size is the total size of all physical extents in the volume group. The unit for vg_size is specified as a suffix. The recognized values for the suffix are m (megabytes), g (gigabytes), t (terabytes), and p (petabytes). If no suffix is supplied, then m (megabytes) is assumed. A vg_size of 512 terabytes would be specified as 512t. Only whole numbers are accepted. The maximum supported vg_size is 2p. NOTE: If the product of the physical extent size and the total number of physical extents for the physical volumes specified on the vgcreate command line is greater than the value specified, then vg_size is upgraded to take account of this size and an informational message is issued. -U unshare_unit Only applicable to volume group 2.2 and higher. Sets the unit at which data will be unshared between a logical volume and its snapshots. unshare_unit is expressed in units of kilobytes (KB) and the supported values are 512, 1024, 2048, and This is an optional parameter and if not specified, the default value of 1024 KB is assumed. The unshare_unit cannot be greater than the physical extent size of the volume group. See lvm(7) for information about snapshots. -x extensibility Set the allocation permission for adding physical extents on the physical volumes specified by the pv_path parameter. extensibility can have one of the following values: y Allow allocation of additional physical extents on the physical volume. This is the default. n Prohibit allocation of additional physical extents on the physical volume. Logical volumes residing on the physical volume can still be accessed after the volume group has been activated by the vgchange -a y command. -E Only applicable to volume groups versions 2.0 and higher. Instead of creating a volume group, this option will display the maximum VG size based on the given physical extent size (-s option) or minimum physical extent size based on the max VG size (-S option). Either -S or -s must be supplied. The output will be in the form: Max_VG_size=x:extent_size=y, where x and y are determined by -s or -S. See the Extent Sizing for Volume Group Version 2.0 and Higher section in lvm(7) for more information. Alternate Links (PVLinks) In this release of HP-UX, LVM continues to support Alternate Links to a device to allow continued access to the device, if the primary link fails. This multiple link or multipath solution increases data availability, but does not allow the multiple paths to be used simultaneously. There is a new feature introduced in the Mass Storage Subsystem on this version of HP-UX that also supports multiple paths to a device and allows access to the multiple paths simultaneously. The Mass Storage Subsystem will balance the I/O load across the valid paths. This new multi-path behavior is enabled and disabled through the use of the scsimgr command. See scsimgr(1m) for details. It is no longer required or recommended to configure LVM with alternate links. However, it is possible to maintain the traditional LVM behavior. To do so, both of the following criteria must be met: Only the legacy device special file naming convention is used in the volume group configuration. The scsimgr command is used to disable the Mass Storage Subsystem multipath behavior. EXTERNAL INFLUENCES HP-UX 11i Version 3: September Hewlett-Packard Company 3

4 Environment Variables LANG determines the language in which messages are displayed. If LANG is not specified or is null, it defaults to "C" (see lang(5)). If any internationalization variable contains an invalid setting, all internationalization variables default to "C" (see environ (5)). EXAMPLES Create a volume group version 1.0 named /dev/vg03 containing two physical volumes with extent size set to 2 MB, from scratch. Initialize the disks using pvcreate. pvcreate /dev/rdsk/c1t0d0 pvcreate /dev/rdsk/c1t2d0 Create a volume group version 1.0. vgcreate -s 2 /dev/vg03 /dev/dsk/c1t0d0 /dev/dsk/c1t2d0 or vgcreate -V 1.0 -s 2 /dev/vg03 /dev/dsk/c1t0d0 /dev/dsk/c1t2d0 The vg_name directory and group file will be created automatically. Optionally, these files can be created before doing the vgcreate, as follows: mkdir /dev/vg03 mknod /dev/vg03/group c 64 0x The minor number for the group file should be unique among all the volume groups on the system. It has the format 0xNN0000, where NN runs from 00 to ff. If the group file is automatically created, any available minor number may be assigned to the group file. Create a volume group version 1.0 named /dev/vg01 that can contain a maximum of three logical volumes, with extent size set to 8 MB: vgcreate -V 1.0 -l 3 -s 8 /dev/vg01 /dev/dsk/c3t4d0 Create a volume group version 1.0 named /dev/vg00 and a physical volume group named PVG0 with two physical volumes: vgcreate -V 1.0 -g PVG0 /dev/vg00 /dev/dsk/c1t0d0 /dev/dsk/c2t0d0 Using the PVLinks feature to create a volume group version 1.0 named /dev/vg00 with a physical volume that can be referenced by two different paths. /dev/dsk/c3t0d0 and /dev/dsk/c4t0d0 refer to the same physical volume, accessed via different controller hardware paths. In this example, /dev/dsk/c3t0d0 becomes the primary link to the physical volume. /dev/dsk/c4t0d0 becomes an alternate link to the physical volume. vgcreate -V 1.0 /dev/vg00 /dev/dsk/c3t0d0 /dev/dsk/c4t0d0 Create a volume group version 2.0 named /dev/vg09 with 2 physical volumes, an extent size of 256 megabytes and a maximum total size of 1 petabyte. Initialize the disks using pvcreate pvcreate /dev/rdisk/disk20 pvcreate /dev/rdisk/disk21 Create the volume group version 2.0. vgcreate -V 2.0 -s 256 -S 1p /dev/vg09 /dev/disk/disk20 /dev/disk/disk21 The vg_name directory and group file will be created automatically. Optionally, these files can be created before doing the vgcreate, as follows: mkdir /dev/vg09 mknod /dev/vg09/group c 128 0x NOTE: Notice that the major number for a volume group version 2.0 or higher is 128 while the major number for a volume group version 1.0 is 64. Also, the volume group number occupies the high order 12 bits of the minor number rather than the high order 8 bits as in volume groups version Hewlett-Packard Company 4 HP-UX 11i Version 3: September 2010

5 Create a volume group version 2.0 of size comparable to a volume group version 1.0 created with pe_size =64, max_pe =4096, and max_pv =16 on an already initialized disk. First calculate the appropriate vg_size parameter as follows: max_pe x max_pv x pe_size =vg_size (in megabytes) 4096 x 16 x 64 = m = 4t. Now create the volume group version 2.0. vgcreate -V 2.0 -s 64 -S 4t vg10 /dev/disk/disk04 Display the minimum extent size required to create a 512 terabyte volume group version 2.0. vgcreate -V 2.0 -E -S 512t Create a volume group version 2.2, named /dev/vg01, with unshared unit of 4096 kilobytes, extent size of 8 megabytes and maximum total size of 4 terabytes: vgcreate -V 2.2 -S 4t -s 8 -U 4096 /dev/vg01 /dev/disk/disk20 SEE ALSO getconf(1), model(1), idisk(1m), lvmadm(1m), pvcreate(1m), scsimgr(1m), vgchange(1m), vgdisplay(1m), vgextend(1m), vgreduce(1m), environ(5), lang(5), intro(7), lvm(7). HP-UX 11i Version 3: September Hewlett-Packard Company 5

6 (Notes) (Notes) 6 Hewlett-Packard Company 1 HP-UX 11i Version 3: September 2010