Novell LINUX ENTERPRISE DESKTOP 11 - DEPLOYMENT GUIDE 17-03-2009 Deployment Manual page 174

Figure 12.2 Physical Partitioning versus LVM
PART
MP
Figure 12.2, "Physical Partitioning versus LVM"
tioning (left) with LVM segmentation (right). On the left side, one single disk has been
divided into three physical partitions (PART), each with a mount point (MP) assigned
so that the operating system can access them. On the right side, two disks have been
divided into two and three physical partitions each. Two LVM volume groups (VG 1
and VG 2) have been defined. VG 1 contains two partitions from DISK 1 and one from
DISK 2. VG 2 contains the remaining two partitions from DISK 2. In LVM, the physical
disk partitions that are incorporated in a volume group are called physical volumes
(PVs). Within the volume groups, four LVs (LV 1 through LV 4) have been defined,
which can be used by the operating system via the associated mount points. The border
between different LVs need not be aligned with any partition border. See the border
between LV 1 and LV 2 in this example.
LVM features:
• Several hard disks or partitions can be combined in a large logical volume.
• Provided the configuration is suitable, an LV (such as /usr) can be enlarged when
the free space is exhausted.
• Using LVM, it is possible to add hard disks or LVs in a running system. However,
this requires hot-swappable hardware that is capable of such actions.
• It is possible to activate a "striping mode" that distributes the data stream of a LV
over several PVs. If these PVs reside on different disks, this can improve the
reading and writing performance just like RAID 0.
164 Deployment Guide
DISK
PART PART PART
MP MP
DISK 1 DISK 2
PART PART PART
VG 1
LV 1 LV 2 LV 3
MP MP MP
(page 164) compares physical parti-
PART
VG 2
LV 4
MP