Unstructured Musings Of A Geek

(and other random stuff)

Declining the Microsoft Browser Choice Update

March 1st, 2010 by Alex No comments »

1st of March brings the “Browser Choice” screen to all XP SP2 or later users via Windows Update, or in my works case via WSUS.

If you don’t want your users to be presented with a choice of browsers to run, (because either they don’t have permission to install software or because you already give your users a choice of browsers – as we do) then there’s a couple of options:

Decline update KB976002 in WSUS (you might want to set your WSUS server not to auto-approve updates until you’ve seen it arrive and have declined it).
Add a registry key to disable showing the balance screen after the update installs.

The update hasn’t appeared on our WSUS server yet – in fact I can’t find anyone on the Edugeek forums who have sucessfully located the update in WSUS yet.

No comments »

Posted in Uncategorized

Converting Windows VMWare machines to KVM

February 24th, 2010 by Alex 5 comments »

I had to do some work on a Windows 2003 virtual server running on VMWare this week which is running on our old playground VMWare install (Server 1.0.4!) and it was sooooo slow I decided enough was enough and it was time to move it on to a sensible platform.

It actually turned out to be quite easy to convert from one platform to the other, with a bit of help from my old boss James Lidderdale.

Shutdown the VMWare server and take a full backup
Boot the VMWare server and uninstall VMWare tools
Apply mergeide.reg registry patch to enable windows to boot on KVM virtual hardware. I’ve no idea where this came from. James had it. I’d like to credit the original author though! Rename .txt to .reg and then merge in as normal.
Shutdown the VMWare server
Convert the vmdk disk image to a single pre-allocated monolithic image:
- ```
vmware-vdiskmanager -r Server.vmdk -t 2 /some/other/folder/Server.vmdk
```
Copy the resulting Server-flat.vmdk image over to your KVM server

Now optionally convert the disk to a qcow2 file:

qemu-img convert Server-flat.vmdk -O qcow2 Server.qcow2

Finally create a suitable virtual machine definition using that file as the main hard drive. If all went well you should see your VMWare machine boot inside KVM.

The first time I tried this it failed miserably. Turned out that the VMWare machine I was working with had snapshots associated with it. In my case, the disk I needed to flatten with vmware-vdiskmanager was actually Server-000001.vmdk. Once I figured that out it worked first time.

5 comments »

Posted in Computing, Linux, Open Source Schools

Why I unsubscribed Audible

January 28th, 2010 by Alex 2 comments »

Because they don’t support Android. Other than that I was a pretty happy customer.

2 comments »

Posted in Android, Books, Computing, Linux

Tags: Android audible

School Christmas Dinner Photo

December 18th, 2009 by Alex No comments »

There’s been a literally a submission for the “best school Christmas dinner” crown:

My Christmas School Dinner, Longhill High School

So here’s the first, and to date only entry. From me! Longhill High School by Innovate Ltd. I can honestly say it’s the best school Christmas dinner I’ve had in recent times.

Turkey roll, stuffing ball, roast and boiled potatoes, carrots, sprouts and parsnips with gravy. Pudding was Christmas pudding and custard.

Well worth a mention were the parsnips. They were so sweet – absolutely delcious. Apparently they’re cooked in oil and honey which explains it.

If you’ve taken a pic of your Christmas Dinner, send it over along with a short review if you like and I’ll add it on!

No comments »

Posted in General, Open Source Schools

Tags: christmas dinner nom

Best School Christmas Dinner

December 13th, 2009 by Alex No comments »

At work our canteen is due to be enlarged next year as we can’t seat all the students during a lunchbreak.

So next week we’ve got a Christmas dinner marathon – with the festive meal three days on the trott – and I was wondering how these three dinners will stack up against the school dinners available nationwide.

I therefore call all school staff to forward me a photo of your school chrismas dinner. I’ll stick them up here and we can see who’s getting the best deal!

No comments »

Posted in General, Open Source Schools

Converting JVC Hard Disk Camcorder Footage

December 12th, 2009 by Alex 2 comments »

When will manufacturers learn?

JVC seem to record their footage in MOD format – which is some strange MPG variant. Very few video editors will touch that, hence the need to convert it.

Trusty ffmpeg to the rescue:

ffmpeg -i input.mod -b 9191k -aspect 16:9 -s 720×576 -acodec wmav2 output.wmv

2 comments »

Posted in Uncategorized

Linux Teacher PC Update

December 11th, 2009 by Alex No comments »

Well we’ve spent a little time on this. Seb’s been helping out and has done the majority of the work so far.

We’ve got the following working:

“Domain” logins (against the LDAP database)
CCTV Software (via Wine)
Themed to look like our standard XP workstations (but not to the extent that you can’t tell the difference. We’re still using the standard Gnome menus). This needs further work.
Promethean ActivInspire for Linux (full marks Promethean)

No comments »

Posted in Computing, Linux, Open Source Schools

lvm2 Snapshot Write Performance

December 11th, 2009 by Alex No comments »

We’re running an OpenFiler based iSCSI SAN at work and have been very pleased with both its speed and reliability, however I was copying some VM images around the other day and it seemed to me that the disk IO was a little laboured.

A quick Google for lvm2 snapshot performance brought me to an article by Dennis van Dok which prompted me to do a little testing of my own.

Here’s the raw results of the tests Dennis proposes on our system:

Without Snapshot
root@virgil:/mnt/vm# sync; time sh -c “dd if=/dev/zero of=/mnt/vm/test bs=1M count=1000; sync”
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 1.79423 s, 584 MB/s

real    0m9.697s
user    0m0.000s
sys     0m2.530s

With Snapshot
root@virgil:/mnt/vm# rm test
root@virgil:/mnt/vm# sync; time sh -c “dd if=/dev/zero of=/mnt/vm/test bs=1M count=1000; sync”
1000+0 records in
1000+0 records out
1048576000 bytes (1.0 GB) copied, 1.67537 s, 626 MB/s

real    0m49.165s
user    0m0.000s
sys     0m2.020s
root@virgil:/mnt/vm#

Now I didn’t carry that out in optimal test conditions. The filesystem is mounted over iSCSI and there’s caching and multipathing in the mix too so this is far from scientific. It’s quite possible that some real traffic from one of the VMs has skewed the result somewhat, but none the less that’s a 5x slow down on write with a snapshot compared to without.

So it’s a tricky dilema. Snapshots are so convenient yet appear to impose such a penalty. We’re going away to rethink how we “do” snapshots.

No comments »

Posted in Computing, Linux

UK Three-Strikes Law

November 28th, 2009 by Alex 1 comment »

If you’re not on to this already:

I did all three.

I can’t convey the pertainent points as well as a certiain Mr Langridge does, so here is a link to his blog post about the subject. I warn you his blog post contains strong language, but I feel it’s justified.

1 comment »

Posted in Politics

Cold Callers

November 24th, 2009 by Alex 2 comments »

It’s 14:15, I should be working, but as I’ve been interrupted twice in the last 15 minutes by <Insert Person Name> from <Insert Company I’ve never heard of> who’s been working with a number of local schools, including ones we exclusively support, I thought I’d take another 2 minutes to express my frustration here.

Five top tips for technology companies calling schools:

Don’t call me. It’s invasive and likely to make me think of your company as desperate for business. Most of the companies we deal with regularly are as a result of word of mouth recommendations or me calling those companies. There is a reason for that.
Don’t bend the truth. If you’re working in a local school then tell me which one but PLEASE don’t try and pretend that you’re big around here when you aren’t. You will be found out.
Don’t post me something and then phone to find out if I got it. Royal Mail are very efficient when it comes to delivering your unsolicited junk to the school, and our lovely post-person is very efficient at getting it to my pigeon hole. I’m equally efficient at getting it from the pigeon hole to the recycling box.
If you simply must phone, please have something interesting to say. Asking me for my 3 year requirements is not my idea of a good use of 10 minutes. We have internal reviews and Becta SRF for that thank you.
Finally if I say I’m not interested in your company, and request that you don’t call again, please respect my wishes. Yes I’m looking at you IT Index/Probrand or whatever you’re called right now. Oh, and getting someone else from the same sales team to call doesn’t excuse this.