[wplug-announce] The Open Pitt, Issue 40

[Vance Kochenderfer]

PDF version: <http://www.wplug.org/w/images/b/b1/Wplug-top040.pdf>

                               THE OPEN PITT
      What's cooking in Linux and Open Source in Western Pennsylvania

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Issue 40                          May 2010                    www.wplug.org
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In this issue:
  Book Review: Practical Virtualization Solutions
  April/May Roundup
  UNIX Curio
  Pitch In!

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                               Coming Events

Jun. 12: General User Meeting.  10:30am to 12:30pm, Wilkins School
         Community Center
Jul. 10: General User Meeting. 10:30am to 12:30pm, Wilkins School Community
         Center
Jul. 31: Installfest. 11am to 4:30pm, Northland Public Library

                    The public is welcome at all events
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Book Review: Practical Virtualization Solutions
by Beth Lynn Eicher

  Authors: Kenneth Hess, Amy Newman
  Publisher: Prentice Hall
  ISBN: 0-13-714297-8
  $39.99, 336 pages, 2010

The Western Pennsylvania Linux Users Group uses virtualization to host our
web site, www.wplug.org.  It is housed on a cloud-based Xen-powered virtual
private server on a physical host run by a company called Linode.  Instead
of worrying about the expense of maintaining our own hardware, paying for a
network connection, and leasing server room rack space, we pay Linode to
rent a portion of a server.  Over the web, the WPLUG Internet committee can
reboot, reinstall the operating system, and configure services with full
root access to our own virtual server.  We virtually have our own system
residing in one of Linode's data centers across the United States and
Europe.

"Virtualization" and "cloud computing" are the hottest buzzwords in
technology today; however, few understand what these terms mean.  To make
matters even more confusing, there is a sea of products for virtualization
solutions, hardware vendors who sell servers that are virtualization ready,
and cloud vendors that lease or timeshare virtualized hosts.  This book
attempts to explain the many virtualization options for a system
administrator audience.

Not everyone uses virtualization like WPLUG does.  Some use virtualization
for temporary projects such as trying new operating systems, demonstrating
a technology for educational reasons, simulating networks for future
studies, or development on emulated hardware platforms.  The focus of this
book is building a virtualization infrastructure for a company.  If is not
your job to decide how to manage your servers, chapter 8 describes
VirtualBox, a free and open source virtualization solution for desktop
users.  This book is primarily targeted toward system administrators who
want to use virtualization for their business needs.

The authors compare the different types of virtualization, discussing how
to choose the virtualization solution that would work best for your
company.  They also cover making the decision between outsourcing your
virtualization to a cloud-based vendor or keeping things in house.  An
important non-technical point in the book is selling management on
virtualization.  Case studies of successful virtualization deployments
round out the book and provide useful real-world examples.

Rolling out virtualization in a corporate infrasructure is a huge project.
This book overall does a good job explaining the reasons why a commercial
virtualization solution matches an enterprise's needs.  Unfortunately, it
was published too soon to discuss the new Red Hat Enterprise Virtualization
product.  It would have been nice if the book discussed the differences
between the XenWorks product by Citrix and Xen.org, an open-source project
which is heavily sponsored by Oracle and Novell.  None the less, this book
is the most complete and up-to-date resource for evaluating virtualization
solutions for an enterprise environment.

Beth Lynn Eicher is a former board member of the Western Pennsylvania Linux
Users Group.  She also writes for whatwillweuse.com, a technology blog
which watches Microsoft's market share.

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April/May Roundup

Apr. 10 General User Meeting: Beth Lynn Eicher spoke about the social
benefits of Linux and other Free and Open Source software.  After covering
the basic philosophy behind it, she discussed what advantages it may have
for home use, in business, and in education.  She concluded that Free and
Open Source software is a unique and effective way to empower nearly any
community.

May 8 General User Meeting: Ted Rodgers discussed deploying and managing
Linux clusters in a high-performance computing environment and the
challenges of scaling normal administration methods to dozens or hundreds
of servers.  He described the network (PXE) booting process and went
through the details of setting up the necessary services and network
configuration.  Also covered were methods for quickly cloning systems over
the network, and a comparison with more traditional automated installation
tools.

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UNIX Curio

  This is the first column in a series dedicated to exploring little-
  known--and occasionally useful--trinkets lurking in the dusty corners of
  UNIX-like operating systems.

This month's column was inspired by an article on the Linux Journal web
site
<http://www.linuxjournal.com/content/add-binary-payload-your-shell-scripts>
describing a custom-built script that would contain a binary tar archive
and, when run, would extract the contents onto the user's system.  Upon
reading this, memories immediately came rushing back of the days of Usenet,
before MIME-encoded e-mail made sending file attachments standard, and
where we walked ten miles each way to school (uphill both ways!) in three
feet of snow.

Yes, at that time, you had to put everything into the body of your message.
But what if you needed to send a bunch of files to someone?  There was
'tar', but the format differed between systems, and e-mail and Usenet could
only reliably handle 7-bit plain-text ASCII anyhow.  You could send
separate e-mail messages (but what if one goes missing?) or put "CUT HERE"
lines to designate where one file ends and another one begins (tedious for
the recipient).  The solution was a shell archive created by the 'shar'
program.  This wraps all your files in a neat shell script that the
recipient can just run and have the files magically pop out.  All he needs
is the Bourne shell and the 'sed' utility, both standard on any UNIX-like
system.

Suppose you had a directory named "foo" containing the files bar.c, bar.h,
and bar.txt, and wanted to send these.  All you'd need to do is run the
following command, and your archive is on its way.

  $ shar foo foo/* | mail -s "Foo 1.0 files" bob at example.com

When the recipient runs the resulting script, it will create the foo
directory and copy out the files onto his system.  You can also pick and
choose files; if you wanted to leave out bar.txt, you could do 'shar foo
foo/bar.c foo/bar.h' or, more simply, 'shar foo foo/bar.?'.

Different versions of 'shar' have varying capabilities.  For example, the
BSD and OS X editions can only really manage plain-text files.  If you had
a binary object file bar.o, it'd likely get mangled somewhere along the way
if you tried to include it in an archive.  They also require, as in the
examples above, that you name a directory before naming any files inside it
(the typical way is to let the 'find' command do the work for you; it
produces a list in the right order).

The GNU implementation is more flexible and can take just a directory name,
automatically including everything underneath.  It can also handle binary
files by using uuencode--a method for encoding data as ASCII that predated
the current base64 MIME standard.  GNU 'shar' rather nicely auto-detects
whether the input file is text or binary and acts accordingly, and can even
compress files if asked.  However, unpacking encoded or compressed files
from such an archive requires the recipient to have the corresponding
decode/uncompress utility, and the documentation is littered with (now
somewhat anachronistic) warnings about this.

Looking at other UNIX systems, the HP-UX version also can uuencode binary
files, and as a special bonus adds logic to the script that will compile
and use a simple uudecode tool if the recipient doesn't already have one.
It will even handle device files and put the corresponding 'mknod' commands
into the script, probably making it the most full-featured implementation
of all.  IBM's AIX doesn't appear to come with 'shar'.  Neither do SunOS
and Solaris, which seems quite odd as original development of the program
is credited to James Gosling!

And so we bid farewell to 'shar'.  Next time you're considering rolling
your own script for a particular purpose, consider whether such a tool
might already exist, just waiting on your system for you to use it.

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Pitch In!

The Open Pitt can only exist if people like you contribute articles.  Have
something to say on a topic related to Free and Open Source software?  Get
in contact with us at <top at wplug.org> and get your ideas out to the WPLUG
community and the wider world!

Don't worry if your writing skills aren't the best.  Bring your ideas, and
we'll be glad to help edit your article and guide you along the process.

If you don't have a topic in mind, consider picking up a review copy of a
book at one of WPLUG's meetings.  We can always use more book reviews to
point out useful references to the community.

In short, only you can prevent The Open Pitt from going on hiatus again.
Give us some articles to work with, and we can keep it going strong for
years to come!

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The Open Pitt is published by the Western Pennsylvania Linux Users Group
<http://www.wplug.org/top/>

Editor: Vance Kochenderfer

Copyright 2010 Western Pennsylvania Linux Users Group.  Any article in
this newsletter may be reprinted elsewhere in any medium, provided it is
not changed and attribution is given to the author and WPLUG.