How to Run Multiple Operating Systems

Operating System Backups

If your computer has two physical disk drives, you can use the second drive

for backing up the operating system and data

partitions. Disk-to-disk backups are fast, easy, and convenient.

They offer

quicker backup and recovery than tape or writeable optical discs.

You can use disk cloning

tools to copy one

entire disk to another, or partition

copy tools to copy

individual partitions across disks. Here’s a list

of free disk and partition cloning tools. I use HDClone Free


to easily copy an entire disk to a backup disk. Like many of the free

tools, it does the job well. Buy the commercial upgrade and you get a

faster copy plus additional features like data reconciliation, data rescue,

and system restoration.

While you can use tools to back up Linux operating

system partitions, I normally just use a few line commands. Here’s how.

Shutdown the Linux system you want to back up and start up a different

Linux instance. Then mount the partition that contains the Linux

partition you

want to back up, and mount the partition you will back it up to. Issue

a cp (copy) command to copy all the files from the source partition you want

to back up over to the destination partition:

cp -av /mnt_source/* /mnt_destination/

On the cp command,

the -a

flag is critically important. It recurses through the subdirectories,

so that all files are copied from the source. It also preserves file

attribute bits and does not follow symbolic links. (If you’re

into the finer points of the cp

command, coding cp -a is the

equivalent of coding cp -dpR).

The -v flag yields verbose

output. It makes me feel secure to see all the file names flying by on the

screen as the files are copied.

If you need to recover the Linux partition, first make sure the file system

in the partition you wish to recover is good. Then use the cp

command again to copy all the files back to the original partition.


boot and run from the new (backup) location. In this case you may have

to update GRUB to add the backup location as a bootable partition in

the OS selection list. And you might have to update the /etc/fstab file inside the Linux

partition to reflect any changed mount point.

Linux offers many other commands for backup and recovery. In addition to cp you can use dd, tar, gzip

or these backup utilities, and you can optionally archive and compress backups.

I’ve shown just one simple but effective technique I’ve found useful for fast disk-to-disk backups.

Backing up and recovering Windows presents a very different

challenge than Linux. Windows offers an exceptional variety of alternatives for fixing a system without resorting to recovery

from an external source. These include Safe Mode booting, restore

points (aka the System Protection feature), Registry export/import, the

System File Checker, Driver Rollback, booting into the Last Known Good

Configuration, the recovery console, the Windows CD “recovery install,”

and more. You can often fix Windows without restoring from an external


If you do need to recover Windows from an external

backup, your options are restricted by Microsoft’s technologies to

combat software piracy. Windows Product Activation (WPA)

and the Windows Registry

are designed to prevent moving Windows between computers

to protect Microsoft’s property rights (you only license Windows,

you do

not own it). These technologies even prevent attempts to easily replace

the motherboard or the OS-resident disk drive if it fails.

Therefore, use imaging tools for disks and

partitions from vendors of backup/recovery products like Acronis. Line commands for copying files like those I illustrated for Linux are not a valid approach with


Frugal Installs

Above I described a traditional install of Linux to a


previously owned solely by Windows. Assuming you have enough disk

space, you

can follow the procedure to install as many additional Linux

distributions as you like.

Some small Linux distros, for example Puppy Linux and Damn Small Linux, offer

another kind of disk install they call the frugal install. (These systems

refer to a traditional disk install as a full install.)

The frugal install simply places the Live CD boot image files on hard disk.

For Puppy Linux this simply means copying three or four files from the Live CD to

the disk.

These files are placed in a single directory or folder within any

existing partition. This partition can be Windows NTFS or FAT32, or any

of the

common Linux partition types, such as ext2, ext3, ext4, or reiserFS. So

you do not have to create a

new disk partition to perform a frugal install, although you may if you

prefer to.

The benefits to the frugal install are:

  1. The Linux distro can reside in any existing partition that

    has sufficient space

  2. No need to shrink the Windows partition or create a new Linux


  3. Easy to upgrade — just replace the older version files with the

    ones from a newer version

  4. Faster boot times than working off a Live CD

With Puppy Linux, these advantages are so compelling that frugal installs more popular than traditional full installs.


No article on installing multiple operating systems would be complete

without a few words about compatibility. Compatibility makes your data

usable across both Windows and Linux. It also addresses whether you can run the same applications under Windows and Linux.

Compatibility between operating systems has several dimensions —

File System Compatibility

Almost any Linux distribution can read or write files on

Windows-formatted disk partitions (NTFS, VFAT, FAT32, etc). This

also means you can create, copy, move, rename, and delete Windows files

and folders as well.

Whether Windows-formatted disk are automatically accessible or must be

manually mounted before they can be used depends on the Linux

distribution. Puppy Linux, for example, requires that you specifically

mount any Windows partition you want to access, while Lubuntu

dynamically auto-mounts everything in sight.

Windows can not read or write files in common Linux file systems (ext2,

ext3, ext4, reiserFS, etc). But you can easily access Linux file

systems from Windows by downloading any of these free programs:

File Format Compatibility — Since most personal computers

run Windows, to most people file format compatibility means “Can I read

and write Microsoft Office files from Linux applications?”

The answer depends on two factors. First, which Linux office suite are

you using? OpenOffice strives for full read/write

compatibility with Microsoft Office files (Word, Excel, and Powerpoint

documents). GNOME Office has an “import” philosophy.

Its goal is to read Microsoft Office files accurately but it doesn’t support directly writing or updating them. Other office suites have their own approaches.

The other key factor is whether you are talking about traditional MS

Office file formats (.doc, .xls, and .ppt) or whether you refer to the

newer “x files” formats (.docx, .xlsx, and .pptx). The latter are

the Microsoft Open Office XML or OOXML

formats. The OOXML formats became Microsoft’s default file formats

starting with Microsoft Office 2007. You can still find many Windows

users driven to distraction by file format differences between the

newer OOXML file formats and Microsoft’s older file formats (even

though Microsoft offers a free download

so that most pre-2007 releases of MS Office can work with the new OOXML

file formats). Given that Windows’ Automatic Updates feature (aka

Windows Update or Microsoft Update) automatically applies updates to

all Microsoft software including Office, I wonder why this update was not automatically applied to

older Office releases?

My experience has been that OpenOffice offers excellent read/write

compatibilty with traditional MS Office files. I’ve exchanged and updated tons of

Word .doc and Powerpoint .ppt files between various versions of MS Office and OO

Office. I’ve found that OO Office is as compatible with traditional MS

Office files as are different versions of MS Office with each other. For example, OpenOffice 3.x is more

compatible in exchanging files with Microsoft Office 97 than are

Microsoft Office 2003 or 2007. This is probably because Microsoft only

regression-tests back one release. Office 97 is two releases back

from Office 2003, three back from Office 2007, and four back from

Office 2010. You can see the problem. With new Office releases every

three years, compatibility deteriorates unless software is

rigorously regression tested for all

prior releases. From my experience I’ve concluded that Microsoft isn’t

much concerned about compatibility beyond ensuring its latest release

is compatible with its immediately previous release.

When it comes to the OOXML file formats, we have an unfortunate situation.

OpenOffice offers partial compatibility but it still maturing in this requirement. There are even slight

differences in x file compatibility between different versions of OpenOffice, such as Go-oo. Part

of the problem here is that there are different versions of OOXML and that

it is itself evolving. (Get the messy background on this fiasco here.)

I hope the situation is eventually resolved and we get back to a world

of easy compatibility. Frankly, most users need this more than they

need whatever advantages OOXML offers. I’ve never heard a single user

say “I wish I had OOXML.” But I’ve heard many

complain about file format incompatibilities when using different

versions of Microsoft Office. Three years on since the introduction of

OOXML and I still hear user complaints when exchanging Office

files across different companies and organizations!

For those who require compatibility specifics beyond the scope of this article, read this Wikipedia article on the subject, or go to the OpenOffice and GNOME Office websites.

Applications Compatibility –

By “applications compatibility” we mean: can Linux run your Windows

applications? Many people find that they have a particular Windows

program they’d like to be able to run under Linux directly. If the

vendor does not already offer a Linux version of the application, try

installing Wine under Linux. Then you can install and run most Windows apps directly under Linux. This list gives you the details on the over 16,000 Windows applications that have been proven to run under Linux using Wine.

If you have really old DOS applications you might install DOSBox on Linux. Designed to run games it also runs many other applications from the DOS and early Windows eras.

How about the inverse case for applications compatibility: can you run

Linux applications under Windows? The general answer is no, not unless

the vendor also supplies a Windows version of the application.

The Bottom Line

Running multiple operating systems on a single computer offers

compelling benefits. It allows you to gain the strengths of two or more

OS’s while only acquiring and maintaining a single computer. For

refurbished computers, multiple OS’s combine the strengths of the

original Windows system, its license, installed applications, and

drivers, with

the thousands of free applications and tools offered by open

source systems. Linux brings free state-of-the-art, secure, supported

software to aging Windows computers. It’s vital to computer


Platform virtualization is the premier method for running multiple

operating systems on current machines, along with Live CD/DVDs or Live


For older systems, Live CDs and multiple OS installs are popular.

Mainstream Linux distributions come with all the tools you need to

co-install multiple operating systems. This includes free tools for

partition management and OS boot selection.

Linux also offers good

Windows compatibility. This includes install co-existence and the

ability to read,

write, and manage Windows files. Office suite compatibility is

situation-dependent. But if it’s important to you there are ways to

achieve it. Linux also runs many Windows applications using facilities

like Wine.

This short article can’t cover all the angles on

running multiple operating systems, so please comment and


your own experiences. What have you learned?

Coming Up…

Past articles in this series discussed how to refurbish mature

computers by revitalizing Windows. Two of them told how to secure and

performance tune Windows.

Starting next month I’ll look at how

Linux contributes to refurbishing. We’ll look at Lubuntu,

Puppy Linux, Vector, and other distros as vehicles for reviving mature

systems. I’ll also offer Linux tips and techniques especially suited to

limited-resource computers. Stay tuned and contribute your own

expertise in comments on

these upcoming articles.

– – – – – – – – – – – – – – – – – – – – – –

Howard Fosdick (President, FCI) is an independent consultant who supports

databases and operating systems. His hobby is refurbishing computers as

a form of social work and environmental contribution. You can reach him

at contactfci at the domain

name of sbcglobal (period) net.

Previous Articles in this Series:


Reuse with Open Source

How refurbishing defeats planned


Scandal: Most

“Recycled” Computers Are Not Recycled

What really happens to many




to Revitalize Mature Computers

Overview of how to revitalize

mature computers for reuse

How to Secure Windows

How to secure Windows

How to Performance Tune Windows

How to performance tune Windows
How Microsoft Missed the Next Big Thing

Microsoft owns the personal computer but is struggling with the emergence of new, smaller platforms


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