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Virtual Machine Tips

August 15, 2006

A quick follow up to yesterday’s post about Parallels. When you create a virtual install of Windows on your Mac, Parallels creates a file. Your OS, applications, and data all live within this file.

Upon installing (and activating) a fresh copy of Windows and all your various applications, make a duplicate of this file. It’ll be a gigabyte or two in size, depending on how much you’ve added, but you can easily store it on a backup drive or DVD.

There are a few reasons to do this. If you’re worried about exposing your Mac to Windows worms and virii, you now have a backup you can restore from at any point. Just move any important data out of the corrupted Windows install, delete it, and make a clone of the backup. Whether that’s easier or harder than maintaining anti-virus software on your copy of Windows entirely depends on how you use it. It’s easier for me, anyway, since my data lives on the Mac portion of my hard drive.

Or if you take the IE team’s advice to heart and decide to maintain multiple versions of Windows for the purposes of testing multiple versions of IE (something I’ve yet to be convinced is necessary, by the way), you can simply clone a few copies of your backup and vary your IE installs between them.

This is all possible with Virtual PC as well, incidentally. The files are much larger, though.

August 15, 13h

The tip with backing up the disk images … that reminds me of something - it’s called VServer and it is a virtual linux machine running on one “master” physical server. We’re using them for a) separating several dev “machines” not to affect each other b) having the possibility of roll back the server that was corrupted to a specific “snapshot” as a whole or exhange them on-the-fly as needed.

August 15, 14h

Hmm sounds like you need what VMWare Workstation 5.5 for PC calls the snapshot manager.

Essentially you create a base build, and snapshot. Continue working and install, say, IE6. Snapshot again.

Then, this is the neat part, you go back to snapshot 1 - and it creates a snapshot branch. Install IE7 and snapshot. You then have 3 snapshots; 1: Base Install, 2: Base + IE6; 3: Base + IE7; and you can switch between them as you like.

You can rinse and repeat this process for any number of snapshot branches. You can even branch from branches. It’s all very elegant, especially when doing development work.

I wonder if the VMWare release that they are doing for Mac will support this.

August 15, 14h

Ah: A picture tells a thousand words.

August 15, 16h

If all of your files exist inside the Windows VM “snapshot,” how easy is it to share those files between operating systems? Can I save a file in Windows and then open it in Mac OSX?

If you cannot share directly on the local machine, are there any problems associated with both operating systems connecting to the same network filesystem? I guess what I’m trying to ask is are both the host OS and the client OS treated as two separate entities on the network (i.e., two separate IP addresses).

I know this is not meant to be a support forum, so I apologize for asking so many questions. However, I’m planning on getting a MacBook before too long, but rely on both some Windows-only apps and some Linux-only apps for work (currently, I dual-boot) and this seems like a pretty nice one computer solution which will give me a pretty slick OS for playtime as well.

August 15, 16h

You don’t need to maintain multiple copies of Windows to test in legacy version of IE. There’s some funky hacks that have been made to run them stand alone. I haven’t tested them yet under Parallels, but when I had a 2nd box running windows, I had versions of IE 3, 4, 5, 5.5 and 6 able to be installed in harmony.

August 15, 16h

@Jonathan Wagner

The way that Parallels does sharing is that you set up shared folders that can be seen by mac and pc sides. And yes they do show up as seperate IPs on the network; it’s pretty neat, ‘cause I run a test web server on the mac, I can access that just by typing the mac’s IP address into the PC side.

August 15, 16h

Thanks SteamSHIFT, that is exactly what I wanted to know.

Now, I wonder how well subversion would handle the snapshot backups. I guess that it would see it as binary, but subversion’s binary diffing seems pretty decent. A daily commit would give you something close to VMWare’s Snapshot Manager that Mark Allanson mentioned for free. I already use this method as a way of syncing my files between three machines as it is.

August 16, 02h

@ Jonathan

Funny I was wondering pretty much exactly the same thing!

Mau says:
August 16, 15h

Has anyone using Parallels experienced better results by disabling the ‘acceleration’ feature?

I have been using Windows without the accel and it works better… anyone has any feedback on this?

Eric says:
August 16, 16h

You write:

“…Whether that’s easier or harder than maintaining anti-virus software on your copy of Windows entirely depends on how you use it.”

I would never *EVER* run Windows without some kind of anti-virus software.

Unpatched and unprotected, Windows is vulnerable from the moment it starts up and is connected to the Internet. Without opening attachments, or Outlook, or even IE.

Mac users who run quite happily (if maybe unwisely) without such protection should be particularly warned about the importance of keeping Windows up to date with relevant Critical Updates from MS; as well as some kind of AV software, even something free, like AVG from Grisoft:

August 19, 13h

I’ve been on a Macbook Pro since about May, and as a web developer, I too agree that its THE best tool we could ever have.

If you’re looking for an easier way to test in IE 5.0, 5.5, and 6.0 I’d highly suggest installing Ubuntu and IEs4Linux package.

Ubuntu is really easy to install and manage. And installing this package is cake.

August 20, 23h

I run both Parallels and Q ( ) for when I need Windows.

I run Parallels while in a closed network and/or need the full speed of the computer.
If I think there is *any* chance that my Windows install could be compromised I run Q and put up with the performance hit.

Q gives you the choice to not save the current session (much like Virtual PC did only free) leaving you with an unmodified Windows install.
Keep in mind though that Q is an emulator so performance is considerably slower than a Parallels virtual machine. This is not so great a problem when checking websites – starting up and launching IE is slow but a page refresh is not so bad.

August 21, 00h

Oops! a stray Q got into that URL. Here it is proper-like:

Groningen says:
August 22, 09h

Thanks for the tip John, just installed Ubuntu, and indeed it runs real easy.

Branko says:
August 23, 12h

Hi guys! I’m messing around in RoR and Django and they have their webservers running on localhost:port. That works like a charm in Safari but how can I access those servers with IE6 through Parallels?

marios says:
September 08, 10h

Having heard recently about parallels, I tried it out 2 days ago.
A programmer recommended VMPlayer which is totally free. I thought to goo the easy route and evaluated the trial of the former on top of XP and installed a Linux Distro from within a Virtual machine, and liked what I saw.
For win-versions better upgrade to 2.2 beta, before building any VM)

I still couldn’t understand though, if Parallel Tools is a MAC only addon,or available for windows version as well.

Most Ideally instead of just bookmarking,I would have done what Dave suggests. No win hosts at all and win2k/xp guest OSes as VM only and clone, wouldn’t like to connect any windows machines without
a Firewall Router that has at least DHCP and NAS.

@Jonathan Wagner

I found I had to implement NAS which does the file-sharing entirely separate from any local machine through SAMBA/CIFS protocol, if I wanted a multi OS network. Since this is an entirely separate story it doesn’t matter wether you access your files from a VM or a real physical machine. There are many cheap solutions around, like NSLU2 from Lynksys for example.
Two caveats:
When accessing from MAC OS those ready made firmwares don’t implement SAMBA in a very nice way,
since Shares loose their permissions and can not go above 700, which makes this pretty useless for local
development.(placing Site Folders on a share)
On Tiger then a Share mounts nicely without enabling those Protocols and opening holes , while happily
having its own native Firewall in Stealth mode

Invisible .DS_Store files could cause problems.

regards, marios