Dot Hill Systems SANnet II 200, Инструкция по установке, эксплуатации и обслуживанию

Страница: 173 / 186

Appendix I Configuring an HP Server Running the HP-UX Operating System I-5
Note –
If you create and map new partitions to the array, you can have them
recognized by the OS without rebooting. Run the
ioscan
and the
insf
commands to
discover the resources and to create their device files.
I.4 Logical Volume Manager
The Logical Volume Manager (LVM) is a disk management system provided by HP in
all versions of HP-UX 11. The LVM allows you to manage storage as logical volumes.
This section describes some concepts used by the LVM and explains how to create
logical volumes on your SANnet II 200 SCSI array. For more detailed information on
the LVM, consult
lvm
(7) and the HP publication Managing Systems and Workgroups:
Guide for HP-UX System Administration (HP part number B2355-90742).
As with many systems 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 using 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. See
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).
Log in as
root
, or
su
to
root
if you are not logged in with root user privileges.