A Word About Backups; Red Hat Enterprise Linux-Specific Information; Device Naming Conventions - Red Hat ENTERPRISE LINUX 4 - INTRODUCTION TO SYSTEM ADMINISTRATION Administration Manual

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5.8. A Word About Backups. . .

One of the most important factors when considering disk storage is that of backups. We have not
covered this subject here, because an in-depth section (Section 8.2 Backups) has been dedicated to
backups.
5.9. Red Hat Enterprise Linux-Specific Information
Depending on your past system administration experience, managing storage under Red Hat Enter-
prise Linux is either mostly familiar or completely foreign. This section discusses aspects of storage
administration specific to Red Hat Enterprise Linux.

5.9.1. Device Naming Conventions

As with all Linux-like operating systems, Red Hat Enterprise Linux uses device files to access all
hardware (including disk drives). However, the naming conventions for attached storage devices varies
somewhat between various Linux and Linux-like implementations. Here is how these device files are
named under Red Hat Enterprise Linux.
Note
Device names under Red Hat Enterprise Linux are determined at boot-time.
Therefore, changes made to a system's hardware configuration can result in device names changing
when the system reboots. Because of this, problems can result if any device name references in
system configuration files are not updated appropriately.
5.9.1.1. Device Files
Under Red Hat Enterprise Linux, the device files for disk drives appear in the
format for each file name depends on several aspects of the actual hardware and how it has been
configured. The important points are as follows:
Device type
•
Unit
•
Partition
•
5.9.1.1.1. Device Type
The first two letters of the device file name refer to the specific type of device. For disk drives, there
are two device types that are most common:
— The device is SCSI-based
• sd
— The device is ATA-based
• hd
More information
Section 5.3.2 Present-Day Industry-Standard Interfaces.
about ATA
Chapter 5. Managing Storage
and SCSI can
directory. The
/dev/
be found in