Moving on

Oct 2, 2007 / 0 comments

On Wednesday 17th October the majority of my belongings will leave Norwich, to arrive in Castlerock at some point the next week (exact day to be confirmed). I will then start work for 3par as a software developer in Belfast on Monday 29th. It's been 6 years since we moved to Norwich and I'll be sad to leave it, and all the friends I've made here, behind. I'd have stayed a bit longer but 3par were keen for me to get started. I imagine I'll be in the Fat Cat on Saturday 13th if people are around. And I expect visited in NI once we get settled in!

Electricity prepay meters and graphing

Sep 21, 2007 / 0 comments

The new house has a prepay electricity meter. My initial reaction was that I'd have to get NIE to come out and replace it with a normal meter, as I have a perception that card meters are awkward and expensive. However some investigation revealed that a keypad meter gets the same 2.5% discount that paying quarterly by direct debit does. The only way to get a larger discount (4%) is to pay a fixed amount monthly by DD.

That would still leave the annoyance of having to remember to top up, but it can be done over the phone with an automated system (you get a 20 digit number to key into the meter) and won't turn off supply overnight or at weekends apparently. Plus, and this is the real reason I'm giving it a while before switching away, it has a nice little satellite keypad/LCD unit. Connected to the main meter unit via a 4 core low voltage style cable. Bets on those being power, ground, rx and tx? You can query the meter on various things, some of which are crying out to be hooked up to a Munin plugin.

The meter is made by PRI and seems to be a Liberty 1E. PRI have a vague page about comms, but little useful information about how to do anything or if the end user can buy anything suitable. I'll drop them an email, but it might just be a case of trying to reverse engineer the keypad protocol so I can talk it. The processor in the satellite is just a Mitsubishi M38223M which has some serial pins, so hopefully it'll be RS232 at TTL levels and something fairly basic over that.

However, before I go about doing this, has anyone else any experience of these meters and care to share details?

Crazy Domino's pricing

Sep 16, 2007 / 0 comments

Brett, JD and I went to Domino's this evening for pizza. The Domino's in Norwich does any large pizza for £9 if you collect, but the Brighton one doesn't seem to have this. In fact, if you order online and get delivery you can get a 20% discount. Which means it's cheaper to sit at home and be lazy that it is to turn up and collect on the way home from the pub. Er, what?

Drawing floor plans

Sep 14, 2007 / 0 comments

Given that the new house is a body of water away I decided I wanted to draw out some floor plans that were to scale, so I could remember how things were laid out and try to get a feel for what will fit where. I'm sure there should be something out there which is easy to use and will allow this, but I ended up with inkscape and vim. I couldn't figure out how to get inkscape to let me specify the size (height/width) of a rectangle, hence ending up with vim to edit the raw xml. Hardly ideal. So. Am I missing how to do this in inkscape, and does anyone have any better suggestions for drawing floor plans? Preferably things in Debian or easily compiled up for it.

SATA hotswap on Linux

Aug 14, 2007 / 0 comments

One thing I forgot to mention in my post about newthe is that I had a play with SATA hotswap while testing it.

I'd ordered the second drive separately, as it worked out a lot cheaper. The main machine arrived first so I configured it up and when the new drive arrived I pulled a spare drive caddy, screwed the drive into it and slotted the drive into the machine. And then wondered how to get it detected (I've memories of rescan-scsi-bus for SCSI drives). I didn't find anything conclusive, so I had a prod around. And eventually realised that it had Just Worked without any action on my part - the /dev/sdb device node had been created and I could setup the new drive and add it to the RAID array. Nice. Pulling the drive also got detected fine - on a reinsertion it became sdc but that's not an issue as I have MD and LVM sitting on top so raw device nodes don't matter so much.

This is with the ahci driver on an Intel ICH7 chipset FWIW. And the decision for software RAID was a conscious one; I've seen drives fail more than once under RAID1/MD and get correctly kicked out of the array while the machine continues running. There are too many different interfaces to hardware RAID from what I've seen, such that you don't get the same level of control and information reporting.

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