Avoiding Common Virtualization Mistakes (Part 1)

Memory Allocation to Virtual Machines:

One of the hardest parts of virtualizing an operating system in a virtual machine is learning that although the virtual machines are very much like physical machines in many different ways, and can perform many of the same tasks they are at the same time very different beasts.

One of the biggest mistakes folks make when they first start virtualizing is allocating the wrong amount of memory to the virtual machines (usually too much).

There are several factors to consider when deciding how much memory to allocate the virtual:

• What OS will the virtual be running?
• What applications will the virtual be running?
• How much RAM is in the host machine?
• Will the host be a workstation or a server?
• What OS will the host be running?

Each of these 5 variables needs special and equal consideration. I will break down each question and give you some pointers for making an educated decision when creating your virtual machines. These variables also ring true across all virtualization platforms no matter if it’s VMware, XEN, KVM, Hyper-V or Virtual Box.

What OS will your virtual be running?

A good starting point for determining the minimum amount of RAM to allocate to your virtual machine will come from the documentation for the guest OS. Check to see what the publisher’s minimum RAM requirement is. Also, for a Linux or UNIX based guest OS; check the requirements for the desktop environment or Window Manager you will be running in the Virtual (if running on at all).

What Applications will your virtual be running?

Besides checking the minimum RAM requirements for your guest OS, you need to take into account how much memory your applications on the virtual will need as well. Again, consult documentation, and understand that you will usually need to add about half of what the application recommends to the overall system memory in the virtual over the OS requirement for comfortable performance. Also, decide now how much you will be multitasking in the virtual OS and take that into consideration as well.

How much RAM is in the host machine?

We will also address the questions “Will the host be a workstation or a server?” as well as “What OS will the host be running?” in this section as well. To start with, running any modern OS on the host, I wouldn’t attempt virtualization without at least 1GB of RAM in the host machine, and preferably 2 GB. Obviously, the more RAM you have in the host, the more RAM you can allocate to your virtual machines. Just how much RAM you can allocate to your virtual machines will depend on the answers to the next two questions. If your host machine is to be a workstation, and you need it to be responsive to host applications while running the virtual, you will need to be careful with how much RAM you allocate to your virtual machines or you will be in “Swap City” before you know it. Also, on the other hand, if your host is a dedicated VM Host server, you can leave less RAM for the host OS and allocate more to the virtual machines since you will not be interacting with the host on its own level.

Also, different host operating systems handle memory very different ways. Generally speaking, Linux will use up more physical memory before it starts to swap and slow down on you than Windows. Taking all this into consideration, if your machine is a workstation, try to keep at least half of your hosts RAM free. If you are running a dedicated host server, you can use up RAM for virtual machines all the way down to the minimum requirement for your host OS and be comfortable.

Real world examples:

My “In a pinch” VMware-Server host:

I have a machine at work that has been in service since October and was set up in a pinch for one of our programmers who needed a quick place to set up two XP VMs to do Delphi builds. I didn’t have a physical host server at the time with enough free resources to meet his request, and we were still in the planning stages of our XenServer project. I did have a recycled desktop workstation which had an Athlon 64 3000+ and 2GB of RAM, so I loaded up Ubuntu Server (CLi only install) and VMware-Server. I gave each virtual 896MB of RAM leaving Ubuntu-Server 256MB for itself. That machine has been running strong since and has only been rebooted once. Sadly, this little soldier is about to be retired as I’m moving those two VMs to a Xen host soon. The moral is, not having the overhead of a Desktop Environment or the need to interact with the host OS gave me the freedom to allocate as much RAM as possible to the VMs and still have them (and the host) perform well.

My “test” Xen Host server:

This guy was an oddball out and has a slightly different revision of the Xeon (Clovertown vs. Harpertown) from the rest of the servers in our Xen Farm. It has become my “test” Xen host and will host test and build workstations for various departments and will be the home of those two XP VMs in the above paragraph eventually. This guy is actually a nice machine –it’s a 2U Dell Poweredge with Dual Quad-Core Xeon Clovertown 2.66GHz chips, but at the moment only has 8GB of RAM (to be upgraded to 16GB or 32GB soon). Right now this guy is sitting at 88% memory utilization running 2 Vista VMs at 1GB each, 4 XP VMs at 512MB each, 2 Windows 2000 VM’s at 512 each and 2 Server 2003 VMs at 1GB each, and each VM is very responsive. Our “production” Xen hosts are Dual Harpertowns with 16GB each and will eventually see similar memory utilization (although on fewer VMs with more RAM each).

My personal Workstation (at home):

This guy was a beast at one time, but seems a little tame now (at least processor wise). This machine has an AMD Athlon 64X2 4600+ (2.4GHz), 6GB DDR2 800 RAM and 3 Hard Drives for a total of nearly 1TB of space and is running Windows XP x64 edition. I do give this machine a beating though, as I use it to test out different operating systems and I have a few VMs on here that I actually use regularly. Having 6GB of system RAM gives me the freedom to allocate a nice chunk of RAM to my VMs. I have an Ubuntu 8.04 and a Vista Business Virtual that have 2GB of RAM each and I honestly don’t even notice when they are running. RAM is getting very cheap right now, so if you are serious about virtualization on your workstation PC, invest in as much RAM as you can afford and/or as much as your Motherboard and OS will handle. Remember, you must have an x64 machine and an x64 host OS to utilize more than ~3.25 GB of RAM.

Good Luck and happy virtualizing!

Windows Server 2008 as a Workstation OS (Part Deux).

Well, it’s been a couple of days since I installed Server 2008 and set it up as a workstation, so I wanted to follow up since I’ve had a couple of days (and a few dedicated hours this evening) to live with it.

I did find some showstoppers for me. Although the OS seems faster than Vista (and nearly as fast as XP), and benchmarks quite well (with synthetic benchmarks), I did not find the WOW! factor that the posters I linked to in my original post found. Also, I found gaming support to be quite poor.

As for performance, it was one of those things I couldn’t quite put my finger on. Somehow the GUI seems much more responsive than on Vista, which to start off gives a feeling of “wow, this is faster than Vista”. However, I found application start times to lag behind Vista a bit. My machine is an AMD 64 x2 4600+ with 6GB of DDR2 800 RAM, and my main drive is a WD 3200AAKS 7200 RPM SATAII w/ 16MB Cache buffer (I have 2 older drives I use for Data storage only). Now, it’s not a full out killer top of the line system anymore, but it shouldn’t take it 15 seconds to start Firefox. I know 15 seconds sounds trivial, but it feels like forever when you are used to it opening instantly.

With gaming, I couldn’t get Battlefield2 to run for more than 5 minutes to save my life! Also, HL2 Lost Cost and CS:Source gave good overall FPS results in the “Stress Tests” (average FPS given at the end of the test), but the graphics looked “jumpy” on the screen - it wasn’t smooth at all and the FPS was constantly going up and down during the test - something I hadn’t experienced before.

I hear you now, “It’s a server OS, it’s not meant for gaming!”, and that is true, but that is a must if I was going to run it as my desktop OS. My main reason for wanting my desktop machine back on a Windows platform was so I could get online w/ my friends and play CS and BF2. I kinda miss it!

Now for a couple of pluses - the OS seems to handle cpu utilization/prioritization better than Vista - 3DMark gave a GREAT CPU score. Also, VMware Workstation was flat out flying even with (the hard to virtualize) Vista running as a guest.

All and all I could see this being a super option for someone needing a true “workstation” - not a home PC - someone who is coding or perhaps dealing w/ 3D modeling would I’m sure be quite happy.

I’ve spent the last couple of hours setting up my machine with Windows XP Pro x64 Edition (x64 is a must with 6GB of ram, and 6GB) and I plan to STAY HERE until I get a new machine (which will definately be after Windows 7 is out).

As a side note, for those who are interested, I’m working up a full review (from a musicians standpoint) on Ubuntu Studio, which is working beautifully on my laptop!

Windows Server 2008 as a Workstation OS.

Ok, so I’ve had this copy of Windows Server 2008 sitting on my bookshelf next to my desk for a few weeks now planning to eventually installing virutalized just to play around, but I recently came across some interesting blog posts and articles about setting up Server 2008 as a workstation OS. Kinda like a anti-Vista so to speak. You can find the articles I read here, here, here, here and here.

Now a word of assurance for the Linux users who follow my site - no I haven’t stopped running Linux at all, I’ve just decided that after all a Windows OS is what’s best for me on my Desktop system. I still have 2 different flavors of Linux dual-booting on my laptop (well, actually it’s triple booting - Server 2003, Ubuntu Studio 8.04 and Foresight 2.0.1 XFCE Edition).

Now I won’t rehash what was included in the articles I linked above, they are very informative, and I reccomend that you read them if you are going to try this for yourself.  I will however give you an overview of my brief impressions.

I loaded the x64 version of the OS and here’s what I found. First off, it’s fast. It’s faster than Vista on this same machine, it’s faster than ANY Linux Distro I’ve tried on this machine (and you all know I’ve tried plenty), it’s faster than DesktopBSD was on this system, and I almost dare say it’s faster than XP Pro x64. As mentioned in some of the above articles, I’m not sure why it’s faster than Vista - they should be about the same, as they are supposed to be both running the same Kernel as of Vista SP1, but it definatly is faster - both in “feel” and in benchmarks.

After going through the above guides, it will look like Vista, and honestly the best way I can describe my experience so far is that it “looks” like Vista but it “feels” like XP. That’s probably a bad analogy, but it’s the best I can come up with right now

I do want to add: Server 2008 is an expensive OS. If you want to try this, please obtain a license legally. I recieved mine from a friend who had recieved it as a freebie and was not going to use it. There is a trial version available from Microsofts web site if you are interested as well.

Also, here’s an added plus for you - after enabling the Desktop Experience package, and enabling Aero I discovered that none of the Vista wallpapers are included (in fact no wallpaper is included except a low-res grainy Server 2008 logo). I came across this site while searching “vista wallpaper” to see if I could find a pack w/ the Vista ‘papers in it. Apparently this guy is the person who took the pictures that became some of the default wallpapers, and there is a downloadable pack on that page with some that didn’t make the cut, but some are stunning in their own right.

And now the finished product:

Three Humans in Hardy!

For all those Ubuntu users who didn’t think one Ubuntu Human Theme was enough there are three variations to choose from in Ubuntu 8.04: Human, Human-Clearlooks, and Human-Murrine.

The differences between them are subtle - sight variations in the hues as well as the variations between the 3 GTK2 enginces (Ubuntulooks, Clearlooks and Murrine respectively).

Try ‘em all three out, and decide which “human” is right for you…I prefer Human-Clearlooks myself!

My apologies…

Due to a jerk amusing himself by posting nonsensical and offensive comments on my blog, I am now going to approve all comments before they are posted.

Please comment away, but expect a delay before it appears.

Sometimes I wish I could “Uninvent” Cellphones.

I’m not sure if “uninvent” is really a word, since it generally wouldn’t be possible to uninvent something that had already been created. I’m seriously having a love hate relationship with cell phones lately though.

Just now I had to run down to the Grocery Store because I bought a nice Sirloin Roast yesterday and I forgot to get some Lipton Onion Soup mix, and we all know it’s nearly a sin to make a beef roast without any Lipton Onion Soup Mix. As I was headed to the store, I passed three little girls, maybe 11 or 12 on bicycles and all three were riding with one hand and jabbering away on their cellphones. This isn’t the first time I’ve seen something like this - it’s getting all too common for my taste. I see little kids and pre-teens all the time in stores, at the mall or just outside (when they should be running and getting exercise) talking away.

Are we as a society getting to a point to where even children can’t “unplug”?

There is another thing I’d like to uninvent if I could and that’s Bluetooth - or at least those little bluetooth things people wear in their ears. They have to be the single biggest personal pet peeve I have. There is a guy at work who works in our call-center taking support calls. His job is to talk on the phone for 8 hours a day, yet every time I see him, either going in, on break, on lunch or leaving for the day he is talking away to some invisible person. If I ever run into him, I’m scared to speak because I don’t know if he’s talking to me or some random person inside his ear (or perhaps his head ) He actually did speak directly to me one day and I felt like a jerk because I didn’t answer him right away - but I was so used to him talking to someone on the phone, I honestly didn’t realize he was directly addressing me.

I have another friend, probably one of my best friends ever who will instantly stop a conversation with me (face to face) to answer his phone. HELLO! I’m right here! We are directly interacting - that is why you have voice mail - if it can’t wait they will vibrate your hip off until you can’t stand it any more, THEN you can answer it, but only then! What I would give to be able to say that out loud!

Do we need cellphones to survive? No!

Do cellphones make our lives easier? I don’t think so - here’s why.

I think as a society we have lost the ability to unplug. We seem to never relax anymore. I love to fish, and even though I’m only 28 years old I remember days not too very long ago when I would easily go spend a day on the lake with no cell phone, no thought of email or computers - just thoughts of landing the big one. Now, I feel sometimes like if I were in a situation where nobody could get in contact with me, I would feel uncomfortable. It seems our whole lives are interconnected, and everything is on show. Stuff like Twitter seems to make that even stronger - I see people twitting all over the place, and sometimes it’s useless stuff. I don’t care what song you are listening too right now - enjoy your music, and I’ll enjoy mine.

I know people at work who answer email as quickly as they answer instant messages. Is that productive or counterproductive? I think it’s the latter - if you are doing your job, you don’t have time to answer 5 emails a minute.

I’m a techy kinda guy but I think some parts of technology are sucking the very life out of what makes us individual, intelligent people. I think every once and a while we should all just “unplug” from everything and get back to what life is really all about. Stop worrying so much and just relax. It’ll be OK. I promise. Break out an encyclopedia (the kind with pages in it) if you need to learn something once and a while. Every once and a while, stop by the Library (you know that big building downtown with all the books in it), and do some research. I forbid you to use a computer while you are there - pull out some microfiche and dig through some old periodicals and newspapers to find some information. Also, while you are at it - try typing something more than a few sentences long, something important that you want to make a good impression on who reads it, and do it all without spelling and grammar checking. Use your noggin - it’s what God gave it to you for.

Sorry for being cynical - I guess I’m just having an Andy Rooney moment

I’m finally actually “using” Gmail…

One of the happiest “geek-days” I remember was the day Gmail announced IMAP access for Gmail - Finally, I could interact directly with GMail from an e-mail client and not let my web-interface got to heck from neglect while using POP3.

Also, IMAP allowed me to use Alpine as my mail client - I’ve liked Pine since I first used it in college (yes we had webmail access, but I prefered to telnet into the system and use pine). Pine is fast, simple, I can move through mail quickly and it protects me from unsightly HTML email (I firmly believe all email should be plain text).

However, for some reason over the last few weeks I’ve been having a heck of a time with my GMail/IMAP combination - I tend to leave Alpine open in a terminal, and my system beep (over my PC speaker) alerts me when there is new mail, however recently Alpine was timing out, and giving a mailbox closed error. Usually I’ve been able to restart Alpine and be back in business, however lately, It’s timed out, wouldn’t let me log in, and on a couple of occasions would report that IMAP wasn’t enabled for my account.

I thought maybe that it was Alpine and not Gmail’s IMAP interface, but I’ve been able to reproduce the errors with Evolution and Thunderbird, so I’ve resorted to what I thought I would never do - I’m using GMails web-based interface. You know what though? It isn’t that bad. I’ve gone through and set up Labels and Filters, and it’s actually quite efficient.

Now if Gmail would only implement the ability to change to a bottom reply by default. I’m sure many people are used to top-reply, however if you spend any time in a mailing list you will quickly be scolded if you top-post.

Reset Compiz effects back to Ubuntu Defaults…

The other day I installed compizconfig-settings-manager and started playing around with some of the advanced settings in compiz, and everything was working OK, I’d just had enough of all the “Extras” and I wanted to go back to Ubuntu’s “Normal” effects as selectable in Appearance Preferences, but apparently, even by doing that some of the extras settings I’d set up in the advanced settings manager wouldn’t go away. I did a quick bit of “googling” and I came by this command that will reset Compiz to the defaults:

Simply hit Alt+F2 and run:

gconftool-2 –recursive-unset /apps/compiz

Hope this helps some other poor soul that got carried away like I did.

Ubuntu for “Humans”

One of the common things I see around the net is people complaining about Ubuntu’s Brown/Orange Human theme. Now I know there is going to be a “new” theme for Intrepid but I just hope as much thought goes into it that apparently went into Human.

I recently tried the new Unity theme in ‘gnome-themes-extras’ and I made a post to show it off. Now I do like the theme, very much, but I ended up switching back to Human. Why? I don’t know - it just feels right I guess. It’s always been the same in the past for me - I’ll try other themes and always without exception, I go back to the default Ubuntu Human.

Perhaps, subconciously I just feel that human is “right” somehow - it’s the first visual cue that says - hey this is an Ubuntu machine I’m on - I just hope whatever theme is created/decided upon for 8.10 is as recognizable as only Ubuntu and has that “just right” feel to it that Human has.

I don’t normally get “excited” about desktop themes and such…

But I think the new Unity theme for GNOME is really hot.

Available in Ubuntu “sudo apt-get install gnome-themes-extras”.

EDIT: updated to include wallpaper which suited the theme better (I think, anyway).