I.5 definitions of common terms, I.6 creating a physical volume, Definitions of common terms – Dot Hill Systems II 200 FC User Manual
Page 199: Creating a physical volume
Appendix I Configuring an HP Server Running the HP-UX Operating System I-5
As with many system administration tasks, you can use SAM to create and maintain
logical volumes. However, some functions can only be performed with HP-UX
commands. The procedures in this appendix are performed using the command-line
interface rather than SAM.
I.5
Definitions of Common Terms
Volume groups are HP-UX’s method for dividing and allocating disk storage capacity.
Volume groups can be used to subdivide a large partition of storage into smaller units
of usable space called logical volumes.
Each volume group is divided into logical volumes, which are seen by the applications
as individual disks. They can be accessed as either character or block devices and can
contain their own file systems.
The underlying physical storage in a volume group consists of one or more physical
volumes. A physical volume can be a single physical disk or a partition of a disk array.
Each physical volume is divided into units called physical extents. The default size of
these units is 4 Mbyte, but can range in size from 1 Mbyte to 256 Mbyte. The
maximum number of physical extents that a volume group can contain is 65,535. With
the default size of 4 Mbyte, this limits the size of the volume group to 255 Gbyte.
To create a volume group larger than 255 Gbyte, you must increase the size of the
physical extents when creating the volume group. Refer to vgcreate(1m) for further
information.
I.6
Creating a Physical Volume
To use a storage resource in the LVM, it must first be initialized into a physical volume
(also called an LVM disk).
1. Log in as
root
, or become
superuser
if you are not logged in with root user
privileges.
2. Select one or more partitions on the array that you want to use. The output of
ioscan
(1M) shows the disks attached to the system and their device names:
# ioscan
-fnC
disk
Class
I
H/W
Path
Driver
S/W State
H/W Type
Description
disk
1
0/12/0/0.6.0
sdisk
CLAIMED
DEVICE
SANnet II 200F R
/dev/dsk/c12t6d2 /dev/rdsk/c12t6d2