Archives for January 2012

Temperature monitoring an iMac

2012/01/17 By staze

When work moved to it’s temporary home during construction, we were forced to move one of our labs to the campus library, into a room that was, not exactly lab-worthy. It’s totally enclosed, and poorly air conditioned. During fall term, the students and faculty that were in that space complained about the heat, and we worked with the library to help address it.

But, new term, and new students/faculty bring new complaints. Problem is, we didn’t really have a good grasp on the temperature in there. So, today I set about fixing that.

There are really 3 things needed to get this working.

Copy of tempmonitor (found here, in /Volumes/Temperature\ Monitor\ 4.94/TemperatureMonitor.app/Contents/MacOS/)
snmpd.conf (will show REAL basic one below)
Script to grab temp, and report it

Really, all of this is pretty darn simple. So, here we go.

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Energy analysis for 2011

2012/01/11 By staze

Another year is done, with 2011 behind us, and another year worth of power data (and for this year, I think I’ll throw in some gas usage data as well in the next post) to look at, and figure out what went well, bad, etc. Of note is that while this year is also a La Niña year, it has been much cooler than last year. We really had no summer at all (summer, by our terms, lasted a couple weeks. Tomatoes this year all ripened within a couple weeks, and late). We haven’t gotten any snow, but we certainly didn’t get many hot days (our hottest day was 91.2F), which now makes 2 years in a row where we haven’t broken 100F. Hopefully this will end after this year (La Niña is only supposed to last 2 years).

Here’s the raw numbers for electricity.

Total Energy used in 2011: 10,475.58KWH ($485.02)
Average Energy use per month: 872.96KWH ($40.42)
Highest energy use day (amount): 2011-12-06 (74.63KWH)
Highest energy use month (amount): December 2011 (1498.92KWH)
Lowest energy use day (amount): 2011-08-18 (9.28kWH)
Lowest energy use month (amount): September 2011 (543.04KWH)
Mean (average) energy use per day: 28.7KWH (~ $1.32/day)
Median energy use per day: 25.9KWH
Mode (most common) energy use per day: 22KWH (had to round this)
Highest energy use at a given time: 18.15kW (registered on 2011-02-02 8:03am)
Lowest Voltage Recorded: 113.5v (registered 2011-02-02 7:59am)
Highest Voltage Recorded: 139.4v (registered 2011-09-12 21:31am)
Average Voltage: 121.1v
Degree Cooling days greater than or equal to 90F: 2
Degree Heating days less than or equal to 32F: 50
Number of rows in DB: 525,142

The first number, since it’s largely the most important when looking at data, is the last one: number of rows. 525,142 rows. There are approximately 525,600 minutes in a non-leap year, which means given my number of rows, I have ~99.91% of possible data for the year, or about 0.09% missing. This certainly is an improvement from last year of 99.57% data.

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Drobo B800i

2012/01/06 By staze

We purchased a Drobo B800i at work during summer break, and initially, I must admit I was a bit confused about it’s functionality. I thought, at a block level, iSCSI device, it was basically a SAN with an internal controller. I was wrong. That functionality sounds like it’s reserved for the 1200i. The 800i, however, is more aptly referred to as a “virtual storage appliance” (or something like that). You throw drives in it (1-8), of any size, then you basically tell it you want volumes. They can be any size from 1TB to 16TB, and as many as 31 of them. They call it “thin provisioning”, and that’s an apt description. It’s much like a VM, only storage. Sure, you can have 30 volumes, all 16TB in size, but only have a single 500GB hard drive in the B800i. Would you want to? Probably not (what would be the point?).

Since purchasing it, and realizing it’s capabilities, I’ve had it take over the role of “backup”. It serves to host previous terms of class data, and our Crashplan PROe data. And by and large, it works very well for that. It’s hard to get real performance numbers that would be useful to most, since I knew it wouldn’t be used for anything needing high performance, and therefore only put Western Digital 2TB Green drives in it (5900RPM. Not fast). It works, and it seems to work well. My only complaint is the software. They MUST use discovery to find the Drobo, and mount the volumes. You can’t, for some reason, specify that there’s a Drobo at this address. Because of this, and some as-yet-unknown issue with the OS X Server firewall, it takes a while for the software to find the B800i, and mount the volumes. But I’m going to investigate this more in the future, or ask that Drobo allow manually specifying the location of the Drobo rather than requiring it be “found”. Also, the software seems to rely on the GPU rendering the interface, which causes issues when combined with Apple Remote Desktop (the software pegs the CPU). I’ve reported this to them, and they weren’t of much help.

All and all, I’m happy. And at the price per TB (weird that it’s gotten to that point), it’s hard to beat it for near-line backup storage. My rating, a full point off, is because of the software issues. The hardware seems quite solid.

[xrr rating=4/5]