Ken's Musings about VMware

Last updated: Monday, 28 March 2005 14:08 -0500

I was first personally exposed to VMware in December of 2001, and almost instantly addicted. Here's the story and what I think about the product and the company.

Whatzit?

If you've never heard of it, VMware is definitely a Cool Product for the computer geek. It allows you to turn your system into a farm of multiple computers, each running a different operating systems. One, called the host system, is the actual OS for the hardware; the others are virtual machines (hence the 'VM' in the company and product name) that are guests on the host system.

This means that you can run one or more virtual Windows systems on a single Windows (or Linux) box; you can have one running Windows 95, another running NT 4, another running Windows 98, three running Windows 2000, and so on -- the limits are only what your hardware can support. Similarly, you can run virtual machines (on either a Windows or a Linux host) for multiple Linux distributions; you could have one running Debian, another with Red Hat 7.1, a third with Red Hat 7.2 (just to try out), another with Mandrake, and so on.

It is really slick, far slicker than I expected despite the raves I've heard from friends and co-workers. I've just gotten started with using it, but I am significantly impressed. As time passes, I'll try to update this page. Right now, my major musing is: get thee a free evaluation copy from VMware.Com and try it out.

Why?

I have two main reasons for wanting to use VMware:

I need cut&paste access to both Windows and Linux for my writings (books and articles about Apache, right now).
I want to replace my decrepit old Windows 95 133MHz laptop with a faster one, while at the same time replacing the Linux laptop I'm currently issued from IBM. I want the best of both worlds (Windows and Linux) without having to possess (and carry about) two separate laptops (as I have for years). And all on hardware I own, without having to rely on the generosity of my employer. (If IBM wanted their laptop back, I'd be in a baaaad way!)

Plus it's cool envelope-pushing technology and I want to be there and play with it, and maybe help it progress by pointing out useful features or identifying bugs.

Problems I've Encountered

As I said above, I'm just getting started with this. When I installed VMware, it on a Red Hat 7.1 host system (an IBM T21 ThinkPad with 384MB, a 20GB disk, 10/100Mbit Ethernet, and a DVD). I have since upgraded to Red Hat 7.2 plus some errata. I'm running a Windows 2000 Professional guest VM. I have had (and am still having) some problems; here's what they are. Hopefully I'll get them resolved.

Display/system hang

This is the real biggie for me. The ultimate problem appears to be that there's some sort of problem with the X driver for my laptop's S3 Savage video chipset. Under some circumstances, the X display will freeze. Sometimes it will go further and actually hang the machine (to the point that a<Alt>-<SysRq>-S won't even trigger a sync), requiring a power-cycle reboot :-(. VMware somehow seems to tend to tickle this bug; it happens more often if I am (or have been) running VMware since starting a particular X session. It may also have something to do with APM.

CPU Speed Misunderstood

Sometimes when I start up my guest W2K system, VMware will complain that my 800MHz CPU is too slow, and is actually a 174MHz CPU. This is only cleared up by a reboot of the host system.

ISO CD-ROM and The Sims

The computer game The Sims^TM uses copy protection, in that it requires that you have the distribution CD-ROM in the drive when playing. Unfortunately, something about VMware's import of the host system's DVD to the Win2K VM fails The Sims' expectations, because the game craps out before displaying the splash page. The Maxis site (makers of The Sims) says this indicates a non-ISO-compliant CD-ROM. It's unclear to me whether that's the case, or something to do with it being a DVD drive rather than a CD-ROM drive. Whatever, I can't play the game in the VM and that sucks.

Serial port from Win2K Guest OS

I'm now having trouble with the serial port passthrough. The first problem was that VMware complained that /dev/ttyS0 wasn't a serial port, which was very puzzling until I went into the laptop's BIOS and turned the serial ports on (d'oh!). Now I'm not sure what the problem is; I installed my LEGO MINDSTORMS system 1.5 in the Win2K guest system and tried to download the RCX. At least some communication occurs, but downloads fail reliably. I'm not sure whether this is because the Linux serial port isn't 8-bit safe, or because the VMware pathway isn't 8-bit safe, or because the 1.5 LEGO system isn't qualified for Win2K.

I've had some ongoing problems with this, such as trying to upload pictures from my digital camera over the serial port. Since I also run the Palm HotSync manager in the guest OS, I have to shut that down before trying to upload images -- and that would only partially work. I had to turn off the HotSync manager altogether so it wouldn't start at guest OS boot, and even them I'm getting less than 100% success rate when uploading images. The busier the host system is, the greater the failure rate.

Outer World networking through the host's wireless card

I'll come right out and say it: VMware's networking has me baffled. I finally managed to get the W2KPro guest to see the host's Samba shares, but reaching beyond that is problematical. I can see one of my systems on the other side of the wireless network (i.e., on the hardline), but I get one of those lame Windows network messages when I try to open it and see what shares it has. I haven't managed to get this to work in any environment, even when the laptop is on a hardline network. Of course, I haven't devoted a lot of effort to it, but I would have liked it to be simpler than it evidently is going to be.

Resolved Problems

Networking

VMware allows you to set things up so that VMs can access the host system's filesystems through Samba. However, the setup for this is apparently non-obvious, at least on a Red Hat 7.1 host system with firewalling enabled. At the moment the only thing I want to do is be able to use Samba between the host and guest systems. I finally managed to get it to work after several hours; I'm not sure which was the triggering factor, but I ended up having to:

make several changes to the /etc/samba/smb.conf file on the host
run lokkit and customise the high-security option to include the following exceptions:
'netbios-ns:tcp netbios-ns:udp netbios-dgm:tcp netbios-dgm:udp netbios-ssn:tcp netbios-ssn:udp'
modify the Win2K guest system's networking to allow NetBIOS over TCP/IP.

Whatever, 'host-network' access is working now. VMware also allows you to set the VM to go through the host with NAT, and also with a bridged network, but I haven't experimented with those yet and so have no comments to make.

Stay Tuned

I intend to use VMware to help me in my writing about multi-platform things (like developing Apache modules), so I expect to exercise the options and get fairly proficient with it. As I make progress I intend also to update this page, so you might want to check back. (Or not.) However, so far I think VMware simply rocks!

coar