Resizing Software Raid Arrays With Mdadm; Understanding The Resizing Process; Guidelines For Resizing A Software Raid - Novell LINUX ENTERPRISE SERVER 10 - STORAGE ADMINISTRATION GUIDE 7-2007 Administration Manual

Table of Contents

Resizing Software RAID Arrays

with mdadm

This section describes how to increase or reduce the size of a software RAID 1, 4, 5, or 6 device

with the Multiple Device Administration (mdadm(8)) tool.

WARNING: Before starting any of the tasks described in this chapter, make sure that you have a

valid backup of all of the data.

Section 8.1, "Understanding the Resizing Process," on page 91

Section 8.2, "Increasing the Size of a Software RAID," on page 92

Section 8.3, "Decreasing the Size of a Software RAID," on page 96

8.1 Understanding the Resizing Process

Resizing an existing software RAID device involves growing or shrinking the space contributed by

each component partition.

Section 8.1.1, "Guidelines for Resizing a Software RAID," on page 91

Section 8.1.2, "Overview of Tasks," on page 92

8.1.1 Guidelines for Resizing a Software RAID

The mdadm(8) tool supports resizing only for software RAID levels 1, 4, 5, and 6. These RAID

levels provide disk fault tolerance so that one component partition can be removed at a time for

resizing. In principle, it is possible to perform a hot resize for RAID partitions, but you must take

extra care for your data when doing so.

The file system that resides on the RAID must also be able to be resized in order to take advantage

of the changes in available space on the device. In SUSE

system resizing utilities are available for file systems Ext2, Ext3, JFS, and ReiserFS. The utilities

support growing and shrinking the size as follows:

File System Support for Resizing

Table 8-1

File System

Ext2 or Ext3

JFS

ReiserFS

Resizing any partition or file system involves some risks that can potentially result in losing data.

WARNING: To avoid data loss, make sure to back up your data before you begin any resizing task.

Utility

resize2fs

mount -o remount,resize Yes, online only

resize_reiserfs

Linux Enterprise Server 10 SP1, file

Increase Size

Yes, offline only

Yes, online or offline