Useful Hyper-V links

This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

In the week or so since Hyper-V RTMed there has been a huge amount of coverage on various websites. Here’s a roundup of some of the more useful articles that I’ve come across recently:

Heterogeneous datacentre management from Microsoft System Center

This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Back in 2005, I quoted a Microsoft executive on his view on Microsoft’s support for heterogeneous environments through its management products:

“[it’s] not part of our DNA and I don’t think this is something that we should be doing.”

Well, maybe things are changing in post-Gates Microsoft. I knew that System Center Virtual Machine Manager 2008 (named at last week’s Microsoft Management Summit) included support for managing VMware ESX Server and a future version should also be able to manage XenSource hosts, but what I had missed in the MMS press release was System Center Operations Manager (SCOM) 2007 Cross Platform Extensions. These allow SCOM to manage HP-UX, Red Hat Enterprise Linux (RHEL), Sun Solaris and SUSE Linux Enterprise Server through management packs with Novell, Quest and Xandros adding support for common applications like Apache, MySQL and (a real surprise) Oracle. Then, for those with existing investments in major enterprise management suites, there are SCOM connectors to allow interoperability between System Center and third-party products like HP OpenView and IBM Tivoli.

I really think this is a brave step for Microsoft – but also the right thing to do. There are very few Microsoft-only datacentres and, whilst I am no enterprise management expert, it seems to me that corporates don’t want one solution for each platform and the big enterprise management suites are costly to implement. With System Center, people know what they are getting – a reasonably priced suite of products, with a familiar interface and a good level of functionality – maybe not everything that’s in Tivoli, UniCenter or OpenView, but enough to do the job. If the same solution that manages the WIntel systems can also manage the enterprise apps on Solaris (or another common Unix platform), then everyone’s a winner.

Some more on using Active Directory for Linux/Mac OS X user authentication

This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Last year I wrote a post about using Microsoft Active Directory (AD) to authenticate users on a Red Hat Enterprise Linux (RHEL) computer (and a few weeks back I followed it up for Mac OS X). This week, I’ve been re-visiting that subject, as I built a new FTP server at home and wanted to use AD for authentication.

In the process, I came across a couple of extra resources that might be useful:

As I was using an almost-new AD (not the old one that I have been tweaking for years), I found that RHEL5 (and Mac OS X 10.5) did not need me to disable digital signing of communications as recent versions of Samba include client side signing. The Samba documentation suggests that it is necessary to set client use spnego = yes in smb.conf when authenticating against a Windows Server 2003 domain controller but I did not find that to be the case with Samba v3.0.23c and Windows Server 2003 R2 with SP2 (perhaps that is the default?).

The following notes may also be useful:

  • SSH does not require any further configuration but if Samba is configured to use the default separator for domainname and username (\) then you will need to escape it – so the connection command would be ssh domainname\username@hostname.
  • This also works for FTP (ftp domainname\username@hostname) but I’ve not found a way to make a simple ftp hostname use AD for authentication.
  • Even though Linux/Unix usernames are case-sensitive, Windows ones are not, so any combination of lower and upper case is valid for domainname\username. Passwords do need to be entered in the correct case (as in Windows).

A sneak peek at the Vista SP1 source code?

This content is 16 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Sometimes I get criticised for writing positively about Microsoft products and being critical of Apple – hey, with the MacBook Air, it’s hard not to notice the lack of substance – what next? an invisible Apple notebook? (thanks to Alex for sending me that – and he used to evangelise almost everything that Cupertino produced before Apple products started to get popular and they began putting shareholders ahead of customers). I like to think that I’m pretty objective but then again my day job does involve consulting on Microsoft technologies so just in case there is any bias around here I thought I’d redress the balance with a little spoof about some Windows Vista SP1 source code that seems to have escaped into the public domain:

/*
  TOP SECRET Microsoft(c) Project:Longhorn(TM) SP1
  Estimated release date: 2008
*/

#include "win95.h"
#include "win98.h"
#include "leopard.h"

char chew_up_some_ram[10000000];

void main() {
  while(!CRASHED) {
    if(first_time_install) {
      make_10_gigabyte_swapfile();
      do_nothing_loop();
      search_and_destroy(FIREFOX|OPENOFFICEORG|ANYTHING_GOOGLE);
      hang_system();
    }
    if(still_not_crashed) {
      basically_run_windows_xp();
      do_nothing_loop();
    }
  }

  if(!DX10GPU()) {
    set_graphics(aero, very_slow);
    set_mouse(reaction, sometimes);
  }

  //printf("Welcome to Windows 2000");
  //printf("Welcome to Windows XP");
  printf("Welcome to Windows Vista");

  while(something) {
    sleep(10);
    get_user_input();
    sleep(10);
    act_on_user_input();
    sleep(10);
    flicker_led_promisingly(hard_disk);
  }

  create_general_protection_fault();
}

(I got this from multiple sources but they all seem to lead back to a Linux Format advert for TechRadar).

Now, the reason I’m posting this is that most Microsofties can appreciate the geek humour and have a chuckle. Sadly the Linux guys at FedoraForum chose to demonstrate their geekdom by descending into discussions of “the M$ tax” and other such ramblings in the vein of “my operating system is better than your operating system”. Yawn! One even commented that slow Vista sales were good for Linux (hmm… how’s that then? There may be a Mac revival going on in the consumer marketplace but I haven’t heard about a massive defection of dissatisfied Windows Vista users moving to Linux – quite the opposite in fact with many people simply reverting to using a familiar Windows XP installation).

I wrote over a year back how, rightly or wrongly, Windows XP would be around for a while yet and with Vista SP1 just around the corner it really does feel as though corporate customers are starting to get ready for Vista now. Personally, I’m looking forward to getting my grubby paws on a beta of Windows 7 (hopefully later this year).

Connecting to a Linux server using VNC

This content is 17 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

Many of my computers are not in my office/den but are providing server functions for which the need to access them directly is rare. When I do need access to the Windows machines, I can connect to them using a variety of RDP clients; for my Red Hat Enterprise Linux (RHEL) 5 box it’s a similar situation but this time using SSH (for command line access) or VNC (for a GUI).

Although RHEL includes a VNC server and I’d opened up TCP port 5900 in the firewall configuration (using system-config-securitylevel), for some reason I was still having problems creating a VNC connection and it turns out that there were two main reasons for this.

  1. Each VNC display will use a new port number, so display 0 is on 5900, display 1 on 5901, etc. I was trying to connect on port 5900 but it’s not as simple as opening the port – I needed to start a session with vncserver (supplying a password if required – the vncpasswd command can also be used for this), then note the port number (open the appropriate firewall ports) and connect from my chosen VNC client.
  2. For connection to an existing logged on console session on the server running a graphical environment (display 0), it’s necessary to enable this in the Remote Desktop preferences:

Remote Desktop PreferencesOnce I’d got around this, it was fairly straightforward to connect to display 1 on port 5901 but the default display was using the rather dated Tab Window Manager(TWM) GUI (although starting GNOME applications like gedit applied the GNOME look and feel to that application’s window. By editing the /root/.vnc/xstartup file I could comment out the twm & line and replace it with startx &; however, because there was already an instance of X running on the server (for display 0), I found that the startx & command failed and I needed to use gnome-session & in its place. I also commented out the line starting with xterm and included gnome-terminal & at the end of the script so my xstartup file now reads:

#!/bin/sh

# Uncomment the following two lines for normal desktop:
# unset SESSION_MANAGER
# exec /etc/X11/xinit/xinitrc

[ -x /etc/vnc/xstartup ] && exec /etc/vnc/xstartup
[ -r $HOME/.Xresources ] && xrdb $HOME/.Xresources
xsetroot -solid grey
vncconfig -iconic &
# xterm -geometry 80x24+10+10 -ls -title "$VNCDESKTOP Desktop" &
# twm &
gnome-session &
gnome-terminal &

Just for completeness, here are a few more notes that might be useful:

  • Use chkconfig --list to check whether the VNC server service is started by default (if necessary, use chkconfig --levels 5 vncserver to make it start in run level 5 in future).
  • If not already running, then start the service with service vncserver start.
  • Kill VNC desktops with vncserver -kill :displaynumber.
  • VNC sessions may be tunnelled through SSH for a secure connection.

Some more about virtualisation with Xen (including installation on RHEL5)

This content is 17 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

I got a little confused by what at first appeared to be conflicting information in the XenSource demonstration that I saw earlier this week and the Xen module in my Red Hat Enterprise Linux (RHEL) training. It seems that I hadn’t fully grasped the distinction between Xen as commercialised by Red Hat and Xen as commercialised by XenSource and in this post I shall attempt to clarify the situation.

Somewhat confusingly, the version 4 XenSource products include version 3.1 of the Xen hypervisor. I’d assumed that this was pretty much identical to the Xen 3.0.3 kernel that I can install from the RHEL DVD but it seems not. Roger Baskerville, XenSource’s Channel Director for EMEA explained to me that it’s important to differentiate between the OSS Xen and the Xen Source commercial products and that whilst both Red Hat and XenSource use a snapshot of OSS Xen 3.x.x, the XenSource snapshot is more recent than the one in RHEL due to the time that it takes to incorporate various open source components into a operating system. Furthermore, XenExpress, XenServer and XenEnterprise are designed for bare-metal deployment with little more than the hypervisor and a minimal domain-0 (a privileged virtual machine used to control the hypervisor) whereas RHEL’s domain-0 is a full operating system.

The XenSource microkernel is based on CentOS (itself a derivative of Red Hat Enterprise Linux) with only those services that are needed for virtualisation along with a proprietary management interface and Windows drivers. Ultimately, both the XenSource and RHEL models include a Xen hypervisor interacting directly with the processor, virtual machines (domain-U) and domain-0 for disc and network traffic. Both use native device drivers from the guest operating system, except in the case of full virtualised VMs (i.e. Windows VMs) in which case the XenSource products use signed proprietary paravirtualised Windows drivers for disk access and network traffic (XenSource Tools).

So when it comes to installation, we have two very different methods – whereas XenSource is a bare-metal installation, installing Xen on RHEL involves a number of RPMs to create the domain 0 environment. This is how it’s done:

Method 1 (the simple way) is to select all of the virtualisation tools during operating system installation. Alternatively, method 2 involves installing individual RPMs. At first I just installed the packages containing xen in their name from the /Server directory on the RHEL installation DVD (kernel-xen-2.6.18-8.el5.i686.rpm, kernel-xen-devel-2.6.18-8.el5.i686.rpm and xen-libs.3.0.3025.el5.i386.rpm) but even after rebooting into the Xen kernel I found that there were no management tools available (e.g. xm). Fortunately, I found a forum post that explained my mistake – I had installed the kernel and userspace libraries but not any of the tools/commands and another post that explains how to install Xen on RHEL:

cd /Server
rpm -Uvh kernel-xen-2.6.18-8.el5.i686.rpm
rpm -Uvh kernel-xen-devel-2.6.18-8.el5.i686.rpm
rpm -Uvh xen-libs-3.0.3-25.el5.i386.rpm
rpm -Uvh bridge-utils-1.1-2.i386.rpm
rpm -Uvh SDL-1.2.10-8.el5.i386.rpm
cd /VT
rpm -Uvh --nodeps libvirt-0.1.8-15.el5.i386.rpm

(--nodeps resolves a cyclic dependency between xen, libvert, libvirt-python and python-virtinst.)

rpm -Uvh libvirt-python-0.1.8-15.el5.i386.rpm
rpm -Uvh python-virtinst-0.99.0-2.el5.noarch.rpm
rpm -Uvh xen-3.0.3-25.el5.i386.rpm

At this point, it should be possible to start the Xen daemon (as long as a reboot onto the Xen kernel has been performed – either from manual selection or by changing the defaults in /boot/grub/menu.lst) using xend start. If the reboot took place after kernel installation but prior to installing all of the tools (as mine did) then chkconfig --list should confirm that xend is set to start automatically and in future it will not be necessary to start the Xen daemon manually. xm list should show that Domain-0 is up and running.

Finally, the Xen Virtual Machine Manager can be installed:

cd /Server
rpm -Uvh gnome-python2-gnomekeyring
cd /VT
rpm -Uvh virt-manager

Having installed Xen on RHEL, I was unable to install any Windows guests because the CPU on my machine doesn’t have Intel-VT or AMD-V extensions. It’s also worth noting that my attempts to install Xen on my notebook PC a few months ago were thwarted as, every time I booted into the Xen kernel, I was greeted with the following error:

KERNEL PANIC: Cannot execute a PAE-enabled kernel on a PAE-less CPU!

It turns out that 400MHz front side bus Pentium M processors do not support physical address extensions (PAE) – including the Pentium M 745 (“Dothan”) CPU that my notebook PC uses – and PAE is one of the pre-requisites for Xen.

Finally, it’s worth noting that my RHEL installation of Xen is running on a 32-bit 1.5GHz Pentium 4 (“Willamette”) CPU whereas the XenSource products require that the CPU supports a 64-bit instruction set. The flags shown with cat /proc/cpuinfo can be a bit cryptic but Todd Allen’s CPUID makes things a little clearer (if not quite as clear as CPU-Z is for Windows users).

Trying to get Red Hat Enterprise Linux to accept a DVD-based repository

This content is 17 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

I use Windows computers every day, I run my home stuff on a Mac and I want to continue to develop my Linux skills – so, I decided to build a Linux server at home. Out came my Red Hat Enterprise Linux 5 installation DVD and a short while later I had a working server. Great. Next, I wanted to customise the installed packages (the installer had given me the option to customise later, which I had accepted) – I fired up the Package Manager and…

…that’s right, a big empty white space in the browse list – the only listed packages were those that had been installed at setup time.

It seems that yum/pirut cannot read the RHEL installation DVD. After some googling, I decided to set up a new repository and created a file in /etc/yum.repos.d called rhel-dvd.repo, the contents of which were:

[dvd]
mediaid=1170972069.396645
name=DVD for RHEL5
baseurl=file:///media/RHEL_5%20i386%20DVD
enabled=1
gpgcheck=0

(the mediaid=1170972069.396645 line is the first line from the .discinfo file on the RHEL DVD, based on a comment on Jeremy Katz’s site.)

Cannot open/read repomd.xml file for repository: dvdIt seemed to recognise my DVD as an installation source but not as a valid repository, so after digging a little deeper I found that mediaid= requires yum 3.1.2 or later and I ended up in dependency hell (exactly what rpm is supposed to avoid).

This is crazy – it seems that Red Hat expect me to install everything from the Red Hat Network (RHN) – what about servers that do not have a connection to the Internet (or to an RHN proxy/satellite server)? Surely installation from the RHEL DVD should be an option (I suppose it is, technically, if I know what every RPM is for – that’s where the pirut browse capability is so useful).

For once, I give in. I could spend hours on this issue (I’ve already spent a few too many) but it’s Friday evening now and my bad IT day has turned into a bad IT week. I need to put the kids to bed and then have a quiet evening in with a large glass (or two) of wine.

In the meantime, if anyone has any ideas on how to get yum/pirut to recognise a CD/DVD as valid installation media, please leave a comment.

The Microsoft-Novell alliance – good, bad or ugly?

This content is 17 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

A few weeks back, I attended a Novell webcast about last year’s Novell-Microsoft collaboration agreement. Although that particular event was for partners, I’ve since found that the same presentation is available to a wider audience so I’m not breaching any NDAs by writing a bit more here about what this is all about.

We live in a heterogeneous world; most of the world’s data centres run a combination of mainframe operating systems, Unix, Windows and Linux. As commodity server hardware takes hold, many organisations previously running Unix-derived operating systems are starting to look at Linux (what Novell don’t say is that many won’t consider running Linux because of concerns about the supportability of open source software). Clearly a move from Unix to Linux is easier than a move to Windows, so (according to Novell), Microsoft has taken the pragmatic approach and partnered with Novell, who claim that SUSE Enterprise Linux is more prevalent in data centres than Rad Hat – the number one Linux distribution (I’m sure that Microsoft would argue that Windows Server 2003 and 2008 include better integration with and application support for Unix-like operating systems).

The Novell-Microsoft collaboration agreement focuses on three technology areas:

  • Virtualisation – virtualisation is a hot topic and the various competing technologies each take a different approach. Novell and Microsoft consider their solutions (with interoperability options for Xen and Windows Server Virtualisation) to give the best in performance, support, interoperability, cost and management (I’d say that’s not yet true, but may soon become closer to the truth with Windows Server Virtualization). Novell are quick to point out that Red Hat now include Xen (since Red Hat Enterprise Linux 5) but only support their own operating system in a virtual environment whereas Novell will support Red Hat, SUSE and Windows (NT/2000/2003) guests.
  • Heterogeneous systems management – today’s server management products are a minefield of standard-based and proprietary software. Under the Novell-Microsoft collaboration deal, the two companies will co-sponsor and contribute to a number of open source WS-Management products. They will also improve federation between Microsoft Active Directory and Novell eDirectory with WS-Federation and WS-Security.
  • Document format capability – Novell describes Microsoft as having a “heathy market share” (I’d call that an understatement – others might consider Microsoft’s dominance of the Office productivity application market to be unhealthy). Novell considers the open document format (ODF) to be growing in support (if not from Microsoft) and project that it will soon become the standard for governments. Under the agreement, Microsoft and Novell will co-operate to make it easier for customers use either or both Open XML and ODF formats.

Under the terms of the arrangement, Microsoft has purchased vouchers that may be exchanged for copies of SUSE Enterprise Linux and will issue them to customers who are looking at Linux in a cross-licensing arrangement that indemnifies SUSE Enterprise Linux users from patent infringement claims – as discussed in episode 93 of the Security Now podcast (transcript) – in return, Novell hopes to become the Enterprise Linux of choice and has issued a similar covenant to indemnify Microsoft customers against claims on their patents.

Remember that this information has come from Novell – not Microsoft – and there is a lot of fear uncertainty and doubt (FUD) circulating at present about Microsoft’s true motives for a Microsoft-Linux alliance (including rumours of open source software’s wide infringement on Microsoft’s software patents).

As an infrastructure architect working for systems integrator, my personal view is that anything that leads to interoperability improvements is a bonus. I’m not sure that’s what we have here – the Microsoft-Novell relationship seems (to me) to be more about marketing than anything substantive (although they have announced a joint technical roadmap) but we’ll see how this works out – it has certainly got the Linux movement up in arms as Microsoft has announced further partnerships with some less significant distributions (including Xandros and Linspire) and consumer electronics giants who use Linux in their products (notably Samsung and LG).

It will be interesting to see how Ubuntu reacts over time (Ubuntu founder, Mark Shuttleworth’s latest reaction is neither hostile nor approving although he did earlier incite OpenSUSE developers to defect to Ubuntu and can now be quoted as saying:

“We have declined to discuss any agreement with Microsoft under the threat of unspecified patent infringements.”

[Mark Shuttleworth, founder of the Ubuntu project]

I’m certainly not expecting a Microsoft deal from the number one Linux distribution:

“We believe…

It was inevitable. The best technology has been acknowledged.

The relentless march of open source is shaking up the industry by freeing customers from proprietary lock-in and lack of choice.

[…]

We will not compromise.”

[Red Hat statement on the Microsoft Novell announcement]

There’s more from Red Hat’s Mark Webbink and ars technica has a good review of why he is ever-so-slightly misguided in his assertion that:

“These guys made noise. Larry Ellison had the effect he wanted to have, and our stock price went down. But let’s see where we all are a year from now. We will still be standing. We still believe that we will be the dominant player in the Linux market because, by that time, there won’t be any other Linux players. We will have succeeded once again.”

[Enterprise Linux News – Red Hat: We will be here in one year, Novell will not.]

Whilst I’ve not spoken to anybody at Microsoft on this particular topic, it does strike me that Microsoft employees are, by and large, either extremely defensive, or a touch arrogant, when open source software is mentioned (to be fair, so are representatives of many companies if you ask them to talk about the competition). Maybe Microsoft can help make a better Linux (as the Linspire agreement suggests) but will they? Well, for one example, they rejected my feature request for Linux client support in Windows Home Server; and one Microsoft employee had a good point when we were discussing my desire to see (ideally not DRM at all, but more realistically) a single cross-platform standards-based DRM solution – “would [Linux users] accept a solution from Microsoft?” (to which I would append “, Apple or any other closed source vendor?”) – probably not.

Further information

Microsoft Interoperability.
Novell/Microsoft more interop.
Novell and Microsoft collaborate – customers win.

Is a picture worth a thousand words?

Novell's new business strategy (from ars technica)ars technica has a visual timeline of the Novell-Microsoft controversy, including this gem of an illustration for Novell’s apparent business strategy.

Problems copying files from a backup… restored by thinking laterally

This content is 17 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

I don’t generally talk about my work (at least not directly) on this blog but, a couple of weeks back, I moved into a new role, which is going to involve working very closely with a certain software company from Redmond (and no, it won’t have any effect on the editorial content here – nothing on this site should be interpreted as representing the views of my employer or their partners). Clearly running Red Hat Enterprise Linux on my laptop wasn’t politically correct (I might have got away with Novell Enterprise Linux) so I needed to rebuild on Windows Vista.

As many of my corporate applications still require Windows XP and IE 6, I run a domain-joined (Windows XP) virtual machine to access them. I had been using VMware Server as the host but as VMware recently sent me a license for VMware Workstation 6.0 (as a VCP benefit) I decided to use that instead following the Vista rebuild. I backed up the virtual machine files to an external disk, rebuilt on Windows (including reformatting the internal disk) got 94% of the way through the restoration of the VM and then I was presented with this message:

Error 0x80070079: The semaphore period has expired.

Not good. I was in the middle of a restore – those files were my backup and the three problem files represented 30% of the virtual disk that makes up my D: drive (i.e. my data).

I’d written the files without errors but clearly something was wrong when reading them. I thought of buying a copy of SpinRite to check that the disk was fine but, before parting with any cash, I tried reading them on another machine and thankfully they restored without any difficulty. I don’t know if the issue was with my Vista machine’s USB device drivers (the successful restore was on my wife’s Windows XP machine), a timing issue (my wife’s machine is older and the external disk was USB 1.1) or something else (like that this is a 60GB FAT32 volume and Windows has a limit of 32GB for FAT32 volume creation – as the virtual machine files totalled 36.5GB in size, maybe the three 1.99GB files that Vista couldn’t read were physically located across and after the 32GB point on the disk) but my experience goes to show that it’s worth trying another machine before giving up totally on the data.

BT Openzone may not work with Linux-based Intel Centrino systems

This content is 17 years old. I don't routinely update old blog posts as they are only intended to represent a view at a particular point in time. Please be warned that the information here may be out of date.

It’s Saturday afternoon, the sun is shining, and I’m in my den, blogging. Which makes me a bit of a saddo.

Actually, I’m just posting items that I wrote in my hotel a couple of nights back… and I’ll soon get back to doing something more wholesome with my weekend. You see, normally I like to stay at Hilton hotels because:

  • In my experience, the rooms are comfortable, with a contemporary décor.
  • The staff deliver great customer service (something that is increasingly rare to find in the UK).
  • I can get a reliable high-speed Internet connection in my room.

Sure, the iBahn Internet connection is pretty expensive (£15 for 24 hours) but if I’m working late into the evening for nothing more that the price of a broadband connection, then I figure that the company is getting value for money. In fact, it’s not unusual for me to work at the hotel the next morning too, because the connection is faster than the one I use at work!

Unfortunately, last Thursday night, the Internet connection in my room wasn’t working, so I tried the BT Openzone hotspot instead. After repeatly trying to connect, I eventually got a connection but lost it before I even had the chance to pay. Eventually, I gave up, figuring that there must be something up with my Wi-Fi stack. Later, I googled “BT Openzone Linux” and found that:

“Some hotspots may not support Linux-based Intel Centrino mobile technology systems”

[buried deep within a BT press release]

Thanks (for nothing) BT. IEEE 802.11b/g access shouldn’t care about my choice of operating system!