Beyond Linux® From Scratch (System V Edition) - Version 2021-04-13

Chapter 5. File Systems and Disk Management

mdadm-4.1

Introduction to mdadm

The mdadm package contains administration tools for software RAID.

This package is known to build and work properly using an LFS-10.1 platform.

Package Information

mdadm Dependencies

Optional

A MTA

User Notes: http://wiki.linuxfromscratch.org/blfs/wiki/mdadm

[Caution]

Caution

Kernel versions in series 4.1 through 4.4.1 have a broken RAID implementation. Use a kernel with version at or above 4.4.2.

Kernel Configuration

Enable the following options in the kernel configuration and recompile the kernel, if necessary. Only the RAID types desired are required. 

Device Drivers --->
  [*] Multiple devices driver support (RAID and LVM) ---> [CONFIG_MD]
    <*> RAID support                                      [CONFIG_BLK_DEV_MD]
    [*]   Autodetect RAID arrays during kernel boot       [CONFIG_MD_AUTODETECT]
    <*/M>  Linear (append) mode                           [CONFIG_MD_LINEAR]
    <*/M>  RAID-0 (striping) mode                         [CONFIG_MD_RAID0]
    <*/M>  RAID-1 (mirroring) mode                        [CONFIG_MD_RAID1]
    <*/M>  RAID-10 (mirrored striping) mode               [CONFIG_MD_RAID10]
    <*/M>  RAID-4/RAID-5/RAID-6 mode                      [CONFIG_MD_RAID456]

Installation of mdadm

Fix a build error introduced by gcc-7.1: 

sed 's@-Werror@@' -i Makefile

Build mdadm by running the following command: 

make

If you wish to run the tests, ensure that your kernel supports RAID and that a version of mdadm is not already running. As many as 9 out of 124 tests may fail.

[Caution]

Caution

The tests edit values in /proc and run tests on software raid devices. They shouldn't be run on systems with active software RAID devices.

Run the tests as the root user: 

./test --keep-going --logdir=test-logs --save-logs

Now, as the root user: 

make install

Command Explanations

make everything: This optional target creates extra programs, particularly a statically-linked version of mdadm and also versions of mdassemble. These all need to be manually installed.

--keep-going: Run the tests to the end, even if one or more tests fail.

--logdir=test-logs: Defines the directory where test logs are saved.

--save-logs: Instructs the test suite to save the logs.

--tests=<test1,test2,...>: Optional comma separated list of tests to be executed (all tests, if this option is not passed).

Contents

Installed Programs: mdadm, mdmon and optionally mdassemble
Installed Libraries: None
Installed Directory: None

Short Descriptions

mdadm

manages MD devices aka Linux Software RAID

mdmon

monitors MD external metadata arrays

mdassemble

is a tiny program that can be used to assemble MD devices inside an initial ramdisk (initrd) or initramfs

Last updated on 2021-02-21 19:43:43 -0600