HP-UX System Administrator's Guide: Overview

(Logical) Volumes

Once you have grouped physical disk drives into disk/volume groups, the collective

space can be divided into logical storage containers that can be smaller or larger than

any individual drive in the group. These logical storage containers are called:

• volumes, if you are using the VERITAS Volume Manager (VxVM)

• logical volumes, if you are using the Logical Volume Manager (LVM)

Once defined, individual volumes or logical volumes can be used for:

• booting (they can contain bootstrap loaders, offline diagnostics, and other software

needed for server administration purposes)

• file systems (traditional file storage)

• swap space (virtual memory / paging)

• dump space (memory dumps following a system panic)

• raw disk access (for use by database applications, and other applications that

manage their own disk space)

Logical volumes can be made larger or smaller as needed (if the data they contain

support these operations).

Figure 3-2 Logical Volumes can be Resized

file system

database

lvol2

lvol1

File Systems

If you are not using a volume (or physical disk) for swap space or raw disk access (for

example disk space managed by a database application), you are probably using it for

file storage.

The directories, files, and file data are usually distributed throughout a volume or disk

drive. In the same way a card catalog allows you to locate a specific book in a large

library, the primary function of a file system is to maintain the pointers to the files

stored in a volume or on a physical disk so that those files can be later retrieved. These

Storage on HP-UX 53