Archive for January, 2010

Cultural Adventures

January 22nd 2010

The last two weekends I have traveled across to London from Faversham to see friends and visit a few museums.

During the weekend of 9/10th I met up with my sister in the British Museum and showed her around (one of my 101 goals ticked off in the process). I was very pleased to finally see the flood tablets I had read about a lot (in brief – a pre-biblical flood narrative dating back to Sumeria that is part of the epic of Gilgamesh that the Genesis writers seem to have borrowed from). Also mid last year a metal-detectorist found the largest hoard of Anglo-Saxon gold ever found, it has been named “The Staffordshire Horde” and is on display there while they catalog it.

On the Sunday we went to the National Gallery and saw The Sacred Made Real a wonderful display of Spanish polychromatic wooden sculpture. It is the best exhibit I have seen in ages and finishes this weekend, go and see it if you can. It is interesting to see sculpture in colour as we are so used to classical and neo-classical sculpture being the very austere white. Interestingly greco-roman sculpture would originally have been painted anyway so the neo-classicists were harking back to something that never really existed.

The next weekend I stayed in Richmond for a friends birthday and we popped to the V&A on saturday and well just wow. I only spent an hour there but it is amazing that London has (at least) 3 really world class museums, it is on par with the British Museum and the Metropolitan Museum Of Art – really fabulous, I will return soon.

On the Sunday I went and looked at the Beatles to Bowie exhibition of 60’s photography, which was pretty good, then returned to Faversham.

All in all good fun in the greatest city in the world.

Posted by tom under 101 & jolly & museum | No Comments »

Building A Backblaze Storage Pod

January 5th 2010

A while ago I saw the Backblaze storage pod and was impressed.

Like many others I thought:

  • I want one
  • Wouldn’t it work great with ZFS
  • The hardware sucks

Building one

I used to make and sell storage servers using Linux a while ago with media streaming software and easy setup (before all the ready-rolled ones came out) so the software side is not a major challenge. Backblaze have released a template for the cases and a list of other components and coincidentally a good friend is a Mechanical Design Engineer and can work on it for me. The cost for the cases drops precipitously if you buy in bulk and he is looking at making it able to be stored flat and easily assembled by folding edges together so I will take the plunge and buy a load, if anyone wants to get hold of some, please get in touch.

ZFS

As soon as you see so many disks in a case like that, it’s hard not to think of Sun’s Thumper and ZFS.

I’ve blogged about ZFS before and given talks on it. With so many disks to fail (either noisily or silently)  data loss is inevitable (and worse – you may not even be alerted), ZFS would solve this (or at least ensure you know about it). BackBlaze use custom application logic to work around this, using TomCat and HTTPS.

It’s Not Highly Available

A chap at Sun has a critique here that is totally spot on and he makes a few great points about subtle changes to Sun’s design to accommodate vibration, noise and electromagnetic radiation. In so many ways the hardware is inadequate and does not have the uptime characteristics of a device in Suns range. That said though an individual device from Sun is not as HA as, say, an EMC SAN (with mirrored write cache, dual SPs etc) as it too relies mostly on commodity hardware. For FiveNines availability you need to decide what you are doing to protect against device failure anyway, the BackBlaze devices just fail faster – that’s your trade-off.

It wont be fast

That is largely a feature of the disks and the controllers; you could get a better motherboard, disks and faster controllers, perhaps eschew the port multipliers too, if performance is a problem. A very cool new feature of ZFS (L2ARC / Hybrid Storage Pools) allows for using SSD as a second level cache, that would help. In linux dm-cache (or here)  could probably achieve something similar.

How can you make it HA?

This is really another blog (and a few weeks work hacking out the ideas), but I can think of several ways of doing what BackBlaze do in their software stack to export files (via NFS, SMB or other protocol) or block devices (ATAoE, iSCSI, NBD etc) in a robust manner.

I have ordered some of the port multipliers, got my friend working on the case and will buy the sundry bits over the next few days.

This is one of my101 goals

Posted by tom under 101 & BackBlazePod & ZFS | 1 Comment »

101 Goals in 1001 Days

January 3rd 2010

I have decided on a kind of hyper-resolution for the new year, 101 goals in 1001 days.
I have a mindmap of the ones I have settled on so far and have started working on some of them already.

To follow (allowing me to tick off some of the meta-goals):

Success criteria for each
Divide them up into “Sustained Effort”, “1-off” and “Requires Break” to make sure I don’t overextend myself. I plan on taking roughly quarterly 1 or 2 week breaks to try and do these tasks. For the sustained ones I need progress metrics, am I on track to complete in the time given?

The actual 101 things!
Need to settle on the actual 101 things, most are on there but it’s still a bit fluid.

As one of my goals is to blog more, you should be hearing more from me in 2010.

Posted by tom under 101 & Life | 1 Comment »