Table 1 Physical Volume Naming Conventions
Type of Device
Device File Name
Persistent block device file
/dev/disk/diskn
Persistent block device file, partition 2
/dev/disk/diskn_p2
Persistent character device file
/dev/rdisk/diskn
Persistent character device file, partition 2
/dev/rdisk/diskn_p2
Legacy block device file
/dev/dsk/cntndn
Legacy block device file, partition 2
/dev/dsk/cntndns2
Legacy character device file
/dev/rdsk/cntndn
Legacy character device file, partition 2
/dev/rdsk/cntndns2
Cluster block device file
/dev/cdisk/diskn
Cluster character device file
/dev/rcdisk/diskn
Each disk has a block device file and a character or raw device file, the latter identified by the
r
.
Which name you use depends on what task you are doing with the disk.
For the boot disk on HP Integrity servers, make sure to use the device files with the
_p2
suffix or
s2
suffix, because they represent the HP-UX partition on the boot disk. On HP 9000 servers, use
the device file without a partition number.
Use a physical volume’s raw device file for the following tasks only:
•
Preparing a physical volume for LVM using the
pvcreate
command. Here you use the device
file for the disk; for example,
/dev/rdisk/disk14
. (The absence of a partition suffix
indicates that you are referring to the entire disk.)
•
Removing LVM information from a physical volume using the
pvremove
command.
•
Restoring your volume group configuration using the
vgcfgrestore
command.
•
Performing a consistency check on a physical volume using the
pvck
command.
•
Modifying the volume group identifier on a physical volume using the
vgchgid
command.
•
Changing the disk type of a physical volume using the
vgmodify
command.
For all other tasks, use the block device file. For example, when you add a physical volume to a
volume group using the
vgextend
command, you use the disk’s block device file for the disk,
such as
/dev/disk/disk14
.
All disk device files are created automatically when a new disk is discovered. For more information,
see insf(1M).
Volume Group Names
Each volume group must have a unique name, up to 255 characters. For example, typical volume
group names are
vg01
,
vgroot
, or
vg_sales
. Although the name does not need to start with
vg
, HP recommends using this prefix. By default, HP SMH uses the names of the form
/dev/vgnn
.
The number
nn
starts at 00 and is incremented in the order that volume groups are created. By
default, the root volume group is
vg00
.
Logical Volume Names
Logical volumes are identified by their device file names, which can either be assigned by you or
assigned by default when you create a logical volume using the
lvcreate
command.
When assigned by you, you can choose any name up to 255 characters.
14
Introduction
