The Linux Sysadmin's Guide to Virtual Disks

The Linux Sysadmin's Guide to Virtual Disks demonstrates the core concepts of virtual disk management. Real-world problems are covered in this book's "Cookbook" section. Included are examples across the difficulty spectrum, from the basic printing of a disk's meta-data, to cloning physical disks into virtual disks. Disk format conversion and disk resizing are both covered in-depth.

Topics include, the Virtual disk cookbook, helper utilities, disk formats, troubleshooting, and performance considerations.

The Linux Sysadmin's Guide to Virtual Disks is written in a tone that is approachable to both newcomers, and experienced veterans. No matter what your experience level, you're guaranteed to learn something new.

Read the book online for free:

• HTML: http://lnx.cx/docs/vdg/output/Virtual-Disk-Operations.html
• PDF: http://lnx.cx/docs/vdg/output/Virtual-Disk-Operations.pdf

Buy a physical copy to support the author:

If you have enjoyed the Virtual Disk Guide, consider buying a physical copy to show your support. Or not, no pressure.

• Lulu.com: Virtual Disk Guide

Table of Contents

• 0. Acknowledgements
• 1. Introduction
• 1.1. Introduction
• 1.2. Typographical Conventions
• 1.3. Units & Prefixes
• 1.4. Getting Help/Feedback
• 1.5. About The Author
• 2. The Virtual Disk Cookbook
• 2.1. Creating Simple Images
• 2.2. Resizing Disk Images
• 2.2.1. Resizing RAW Images
• 2.2.2. Resizing QCOW2 Images
• 2.3. Query an Image for Information
• 2.4. Converting Between RAW and QCOW2
• 2.4.1. Convert an Image from RAW to QCOW2
• 2.4.2. Convert an Image from QCOW2 to RAW
• 2.5. Creating Disks with Backing Images
• 2.6. Comitting changes to a backing image
• 2.7. Cloning a Physical Disk
• 3. Disk Concepts
• 3.1. Creating a 1GiB virtual disk from scratch
• 3.1.1. Background on the dd command
• 3.1.2. Running dd
• 3.1.3. Examining the Created File
• 3.1.4. Create a Partition Table
• 3.2. Devices and Partitions
• 3.2.1. Introduction
• 3.2.2. Creating a Loop Device
• 3.2.3. Examine the loop device
• 3.2.4. Creating partitions
• 3.2.5. Formatting Partitions
• 3.2.6. Cleaning Up
• 4. Helper Utilities
• 4.1. libguestfs
• 4.1.1. guestmount
• 4.1.2. virt-filesystems
• 4.1.3. virt-rescue
• 4.1.4. virt-resize
• 4.1.5. virt-sparsify
• 4.2. virt manager
• 5. Disk Formats
• 5.1. RAW
• 5.2. QCOW
• 5.3. QCOW2
• 5.4. Other Formats
• 6. Performance Considerations
• 6.1. I/O Caching
• 6.1.1. Write-back Caching
• 6.1.2. Write-through Caching
• 6.2. I/O Schedulers
• 6.2.1. Additional Resources
• 7. Troubleshooting/FAQs
• A. Appendix: Man Pages
• UNITS — decimal and binary prefixes
• B. Appendix: Disk Drive History
• B.1. Disk Drive Components
• B.2. Access Modes
• B.2.1. CHS Addressing
• B.2.2. LBA Addressing
• B.3. The Master Boot Record
• Glossary
• Colophone

Building the Document

Compiling this documentation requires:

• xsltproc
• dblatex
• docboook5 stylesheets (http://sourceforge.net/projects/docbook/files/docbook-xsl-ns/)
• make
• Adobe Source Code Pro/Source Sans Pro fonts (store *.ttf files in ~/.fonts/)

Fedora Packages with some of these dependencies:

• xsltprox available in libxslt
• dblatex available in dblatex

There is a basic setup script in misc/setup-docbook.sh.