Monitoring I/O on Linux

On my Ubuntu 8.04 machine I run a Windows virtual machine to allow me to use Adobe Lightroom for image editing.  I primarily use Sun xVM VirtualBox for this, thanks to the great price (free)

Until a few days ago I hadn't realised that VirtualBox does not currently have SMP support, which I believed may explain why I was getting particularly bad performance inside the VM.  As a result I decided to try VMware Workstation, which does have SMP support

The result was actually worse... but I changed a couple of other variables too (big ones, like installing Windows Vista instead of XP).  Instead of jumping straight back to VirtualBox+XP I decided I'd have a look at what was actually going on

It turns out that this wasn't going to be as easy as I'd hoped... io profiling in Linux is limited to say the least... beyond top for the iowait value and iostat, you can't really see what's going on

Just as I was beginning to despair I decided to see what Linux had to match Brendan Gregg's excellent iotop DTrace script and it turns out there is a Python equivalent that uses experimental new io accounting available in Linux kernel 2.6.20 and above

The Linux iotop (which will be available in the Ubuntu 8.10 repos) did allow me to determine which threads were reading/writing to disk.  The net result is that I now know that both vmware-vmx and smbd were making heavy use of my home disk, most likely due to Lightroom building 1:1 previews for all of the images in my catalog

Thanks to some very clever individuals, Linux is slowly getting some of the features that Solaris has had for some time.  But wouldn't it just be easier to port DTrace to Linux?

So long, old friend

Earlier this week I sold my gorgeous Sony Vaio X505/CP laptop on eBay.  The X505 is truly a work of art, both in terms of appearance and engineering



At a mere 0.8KG the X505 packed an impressive 1.1GHz Pentium M processor, 512MB of RAM and 20GB hard disk drive... lightyears ahead of the new MacBook Air!

Sad as I am to see the X505 go, I'm also looking forward to buying myself a new laptop, which will replace the X505 and my current desktop PC

This will be a Dell M4300... so, not quite as luggable as the X505, but it should strike a good balance between portability and function.  I'm specifically after an M4300 with a minimum 2.4GHz C2D CPU and the gorgeous 15.4" 1920x1200 display (the same as my Dell 24")

Let's hope the new owner treats this brilliant piece of kit as well as I did

Pobo's return

A couple of weeks Xiaoxiao was back in the UK for a very short trip.  Her visit coincided with Quentin sailing into Liverpool after 12 months at sea; I think he was more than a little surprised to see her standing in Albert Dock

Apart from seeing Quentin in, we spent another day in Liverpool, enjoyed stunning Metropolitan Cathedral as well as Liverpool Cathedral, not to mention trips to Williamson's tunnels and those funny iron blokes stood in the sea

On the way back we enjoyed a film at Manchester AMC and our Indian restaurant of choice, Punjab along the curry mile.  Amazingly at least one of the waiters still remembers me from my regular visit almost three years ago.  Not bad going, if you ask me

Xiaoxiao is back at work in China now and after a week back at work I'm also slipping into the usual routine.  Last week my boss conducted my annual review, which I'm happy to say was very positive.  In the (hopefully not too distant) future I'm going to be getting a little more involved with the kernel "community", with the possibility of being able to tag two to four weeks onto the end of my next trip to China working in one of the Chinese Sun offices

Desk upgrade

This afternoon I decided that my monitor was too low.  Over the past couple of weeks I've increasingly noticed how I hunch up while using my computer, both at work and at home

After hunting around for something to use to boost the height of the monitor I realised that just last month I'd bought some new stands for my Yamaha 'speakers... I decided to try the old wooden stands on my desk

After being initially laughed at by Vlad, both of us now have ex-Yamaha stands on our desks... the difference is absolutely amazing!  Next up is an upgrade to my desk at work