Mac VMM Eval

Macintosh OS X Virtual Machine Manager Evaluation

Introduction

Results of comparative evaluation of various Virtual Machine Managers (VMM) environments on a Macintosh Operating System Ten (Mac OS X) host . Though not as comprehensive as it could be for a well-founded comparison, the study presents preliminary results from evaluating VMMs for personal use to meet the evaluator's particular needs. Evaluation accomplished at author's own initiative and personal expense in time & treasure including software/hardware acquisition/maintenance (i.e. no sponsorship axes to grind).

Work in Progress

This is an evolving draft with expectations of updating as learning progresses. Initial comment is a summary of lessons learned over several months of evaluation during last half of 2008 and continuing into early 2009. Follow-up comment should provide more detail specifics and information updates.

VMMs evaluated

Three VMMs were installed & run over a period of time to perform normal functions as a production environment with notes taken along the way. This is intended to be a summary of knowledge, understanding, and wisdom gained along the way from that experience.

The three VMMs evaluated:

• Parallels © v 3 (ParaLL)
• Virtual Box © v 2 (VBox)
• VMware Fusion © v 2 (VMwF)

In use as VMMs, each displays peculiarities of behavior. Some can be considered minor (like the differences in operating & driving different cars). But, some, however, would appear to be shortcomings that stem from issues related to proper handshaking between the host Mac OS X and the VMM applications that act as intermediaries between the Mac and the guest VMs. Some peculiarities can be lived with but some may be show stoppers for normal use until addressed in software updates.

Host OS environment

MacBook running Macintosh OS X v 10.5/Leopard as host, updated thru v 10.5.6 running on 2.4 Ghz Intel Core 2 Duo with 2 Gb RAM and 250 Gb hard disk drive (hdd).

Guest VM environments

Installed as guest OS, each in its own Virtual Machine (VM) were:

• MS Windows XP (WinXP)
• Ubuntu Linux v 8.04/LTS (Hardy Heron) 32-bit (Ubuntu32)

EARLY NOTES

Use of software evaluation periods

Probably best to use the full evaluation period before buying & registering products (VMM & OS). Doing so appears to lock you in to the particular VMM environment, at least for running a particular Microsoft (MS) Operating System (OS) installation. Activating MS XP/Vista locks in that copy to the particular VMM environment, wherein it is activated. Trying to migrate it to another VMM environment apparently triggers MS anti-fraud features (detecting "illegal" copy -- i.e. beyond current MS licensing permissions wording). It may be possible to find a way of moving an activated copy of MS XP/Vista to another VMM, but it certainly does not appear to be easy.

Functionality of different VMMs

As with driving different model cars and with using different computer Operating Systems (OS), driving different model VMMs can become an issue once muscle memory begins to take over from conscious memory. Partly, the issue is where to find on the screen system feedback information and clickable hot spots (which window, where on the screen). Secondly, different keyboard shortcuts are used to perform common VMM functions. Obviously, this becomes mute when only a single VMM product is in use. But, even these differences can fade as problematic issues over time, just as one can become used to driving different cars, trucks, tractors, and other similar equipment on a regular basis.

Virtual vs hardware-based machines

For the most part, working on a VM is essentially the same as on a hardware-based installation of the same OS. But a few peculiarities have arisen that will be pointed out here:

• VBox USB device interoperability issue (a show stopper -- see below)
• eSword functionality issue (minor, but not fully functional in VM)
• ParaLL USB device interoperability issue (minor irritant)

re: VBox USB device interoperability issue : A pdf document describing details of symptoms available upon request. (change: 2009.07.01 -- hyperlink to on line document no longer available)

Work in progress to address these issues. Further evaluation expected to continue as time permits and interest/desire continues to prioritize it high enough to be addressed above other demands.

Mac Back (up)

Mac “Time Machine”

Automated Backup on Macintosh Machines

New Feature on Mac OS X v 10.5 – Leopard

The Macintosh Leopard Operating System (OS X version 10.5) released in October of 2007, introduced an automated back up feature called the Time Machine. A few things that have become apparent from using Time Machine:

• Time Machine apparently needs an external read/write hard disk drive (hdd) plugged in to function. The best I could determine so far, a DVD will not work. Regardless of whether Time Machine can read/write to DVDs, their capacity is far too small. Even multi-layer DVDs can only hold about 17 Gb (double sided, double layer each side).

• Before Time Machine is set to do back ups, it will ask if a new external hdd plugged in to a USB or FireWire port is to be used as the back up. CAUTION: It also will want to reformat the external hdd to a Mac format ( HFS+ ). A good technical review of the Mac Time Machine that seems to reflect my own experience can be found at URL: http://arstechnica.com/reviews/os/mac-os-x-10-5.ars/14 – at least the first part, before the review digs deeply into technical detail where only Nerds or Geeks may care to tread. Per a Wikipedia description of Mac 10.5/Leopard (at URL: http://en.wikipedia.org/wiki/Mac_OS_X_v10.5 ) back up drive should be larger than the Mac's hdd. This makes sense for the obvious reason that the whole Mac hdd could not otherwise be backed up.

• The external hdd used for a Time Machine backup does not need to be plugged into the Mac all the time. Left plugged in, it will do hourly backups, but it may be "ejected" from the Mac, set aside, and only plugged in as desired to ensure that your system is backed up -- once a day, for example. But note that, the longer the Time Machine hdd is left unplugged, the longer a back will take.
• If the Mac is left idle long enough to go to stand-by powered down status (i.e. power button must be used to bring back up vice simply moving the mouse cursor), some external hdd may also shut down to stand by status. When the Mac wakes up, it finds the external hdd gone and gives a warning about the device being removed and potential for loss of data (i.e. the Mac OS did not manage the shut down and there may be loose threads not properly closed, such as data cache clearing or saving of active file modifications.) In this case, the Mac Time Machine appears to simply go to delayed back up mode – scheduling back up for when the hdd is reconnected. (This behavior noted using WD My Book Studio Edition with USB 2.0, FireWire 400/800, and eSata interfaces – preformatted for use with Macintosh – and used via the Mac's FireWire port.)

• Quick info on status of Time Machine is available via an icon on the Mac's top menu bar, where a mouse click pulls down options for adjusting or using the Time Machine to back up or restore individual files/programs.

Considerations

But, I have still not ruled out the possibility of using a smaller USB drive temporarily at least as emergency back up before being able to acquire a large enough external hdd. (But note Time Machine wanting to reformat the drive & losing any data already on the drive.) In a week's of use, a 250 Gb hdd Mac had consumed 170 Gb of space on a dedicated Time Machine hdd. This covered installation of several applications (apps) including several Virtual Machine (VM) managers. Each of three VM managers ran it's own set of Ubuntu Linux and MS XP VMs. And each VM manager had its own “snapshot” back up feature for rolling back to previous versions of each individual VM. Each VM, in turn, contains its own soft copy hdd image containing its operating system and installed apps, each VM consuming ca. 5 – 25 Gb on the Mac hdd.

I've found large capacity external drives that have brought the cost down to less than 50 cents per gigabyte. Just saw a 1 Terabyte USB hdd for a little more than $200 – close to 20 cents/Gb. I've seen external 500 Gb hdd in the low to medium $100's range with those having FireWire & eSata interfaces a little higher, but still under $200.

When you consider the cost in time, treasure, effort, and frustration in recovering from data loss – if your work can even be recovered at all – not to mention lost opportunity cost (things you could not do while trying to recover), it may not take long to spend far more than the $200 price of an external high capacity drive and simply plugging it in. The old adage would seem to apply: “Are you concerned about the price or the cost?”

Mac - Under the skin

Understanding Mac OSX architecture:

-- "Mac OS X System Architecture" at URL:

http://developer.apple.com/macosx/architecture/index.html

lays out a graphical representation of the Mac OSX operating system that you can explore using your mouse to move the pointer around to get explanations and clicking to drill down for more, in-depth explanation.

-- Wikipedia article, "Architecture of Mac OS X" at URL:

http://en.wikipedia.org/wiki/Architecture_of_Mac_OS_X

provides a historical overview of how DARWIN flavor of "Unix" used as the core kernal underlying Mac OSX operating system came about to be.

-- Wikipedia article, "HFS Plus" at URL:

http://en.wikipedia.org/wiki/HFS_Plus

gives an overview of the special format used on Mac hard disk drives (hdd).

(NOTE: the Mac Time Machine will try to reformat a hard drive to HFS+ format, if you agree to it's using a plug-in USB-drive as your back up drive.)

MS Windows can read HFS+ disks only by using add-on software (see near end of this web page). Over the years, MS has used it's own hdd formats, including FAT16, FAT32, and NTFS. Older versions of MS Windows will not read/write from/to newer MS hdd formats. Linux, in turn, has some specific hdd formats of its own.

-- Wikipedia article, "Linux" at URL:

http://en.wikipedia.org/wiki/Linux

lays out a good overview of LINUX as an Operating System (OS) and it's relationship to the original UNIX OS. Evident in the article is how the Open Source community can provide a powerful means of producing high quality, powerful software.

While seemingly like the "Wild West" with everyone doing his own thing, the open development scene provides opportunities for the "cream to rise to the top" -- where the high quality software can be found. The Mac DARWIN kernal and Ubuntu Linux are two examples.

Two desktop environments available in the Linux world -- KDE & Gnome -- can be considered comparable in quality to MS Windows and Mac OSX.

-- Wikepedia article, "GNU Project" at URL: http://en.wikipedia.org/wiki/GNU_project offers an overview of the how an open source alternative to the proprietary Unix OS came to be, including the evolution of an Open Source community centered around the Free Software Foundation (FSF) -- ( FSF home web page ) and the Open Source Initiative (OSI) ( OSI home web page ).

-- Wikepedia article, "POSIX" at URL:

http://en.wikipedia.org/wiki/POSIX

provides some technical background on the accepted standard for what a Unix-like (sometimes seen as *NIX) OS should be and how it should function. Mac OSX is considered fully compliant with the POSIX standard. Interesting enough, the MS NT kernal that underlies MS Windows XP & Vista can be considered "POSIX compliant" when appropriately set up with MS compatiability package.

---eof