Datasheet

“main” (Installation and Administration) — 2004/6/25 — 13:29 — page 139 — #165

Special Installation Procedures

Delete Partition Table and Disk Label

This completely overwrites the old partition table. For example, this

can be helpful if you have problems with unconventional disk labels.

Using this method, all data on the hard disk is lost.

3.10.1 Logical Volume Manager (LVM)

Starting from kernel version 2.6, you can use LVM version 2, which is

downward-compatible with the previous LVM and enables the continued

management of old volume groups. When creating new volume groups,

decide whether to use the new format or the downward-compatible ver-

sion. LVM2 does not require any kernel patches. It makes use of the device

mapper integrated in kernel 2.6. This kernel only supports LVM version

2. Therefore, when talking about LVM, this chapter always refers to LVM

version 2.

Instead of LVM2, you can also use EVMS (Enterprise Volume Management

System), which offers a uniform interface for logical volumes and RAID

volumes. Like LVM2, EVMS makes use of the device mapper in kernel 2.6.

The Logical Volume Manager (LVM) enables ﬂexible distribution of hard

disk space over several ﬁle systems. As it is difﬁcult to modify partitions on

a running system, LVM was developed. It provides a virtual pool (Volume

Group — VG for short) of memory space from which logical volumes (LVs)

can be generated if needed. The operating system accesses these instead of

the physical partitions.

Features:

Several hard disks or partitions can be combined to a large logical

partition.

Provided the conﬁguration is suitable, an LV (such as /usr) can be

enlarged when the free space is exhausted.

Using LVM, even add hard disks or LVs in a running system. How-

ever, this requires hot-swappable hardware that is capable of such

actions.

Several hard disks can be used with improved performance in the

RAID 0 (striping) mode.

The snapshot feature enables consistent backups (especially for

servers) in the running system.

139SUSE LINUX Enterprise Server