Graphing CurrentCost using RRDtool

I’ve not been doing much with my CurrentCost data lately, having been slightly distracted with upgrading my home server OS. Well, upgrading is possibly a slightly odd description for a running a new live CD system but to compile rrdtool I grabbed the latest version (6.0.7) of SLAX instead of SLAMPPLite which is based on an older release. I really like the new version of SLAX so I’ve been experimenting with some home server type customizations, manually so far since MySLAX creator only seems to understand older versions, but I might give SLAX Tools a go too.

Anyway, while not quite as interesting as Dale’s CurrentCost bill, I now have a working RRDtool SLAX module. RRDtool seems ideal for graphing CurrentCost data. I’m aiming for something like this example, which would be perfect for viewing on a TV using the Wii but to start with I’ve been giving it a simple trial run over the last day. Here are the results so far:

RRDtool power graph

Looking pretty good, and I think there are a few more features of RRDtool that could prove useful.

Update: found another great example of using RRDtool for CurrentCost data, which has a link to another page with exactly the kind of RRDtool settings you’ll need for a CurrentCost meter! (17 November 2008)

Update: looks like Chris Dalby has RRDtool hooked up as well now. Hope to post about RRDtool again soon with the commands I’m using; just need a couple more tweaks! (7 December 2008)


Home server OS

Choosing the hardware took a while but that was nothing compared to tracking down a Linux distribution to use! I’m a big fan of DSL and, being damn small, it runs a treat on the Netvoyager but it’s purpose in life isn’t really as a home server. So began a hunt for a Damn Small Home Server Linux distribution which has eventually led me to…

SLAMPPLite uses the XAMPP server suite, and is low fat version of the “instant home server” SLAMPP. Sounded promising! So far it’s lived up to expectations, running the XAMPP samples without any noticeable delays- here’s how it looked with everything running (though not necessarily doing anything!)…

top - 02:55:44 up 9 min,  1 user,  load average: 0.49, 1.38, 0.94
Tasks:  80 total,   1 running,  79 sleeping,   0 stopped,   0 zombie
Cpu(s):  2.6% us,  3.9% sy,  0.0% ni, 93.6% id,  0.0% wa,  0.0% hi,  0.0% si
Mem:    119544k total,   116608k used,     2936k free,     9428k buffers
Swap:        0k total,        0k used,        0k free,    55916k cached

So a pretty tight squeeze, but on a £95 box (they reduced it after I bought one!) I’m more than happy. As an added bonus, SLAMPP/SLAMPPLite are based on SLAX, which made recompiling the broker for publishing CurrentCost data a snap, plus you get some handy tools for customisation, including the MySlax Creator gui for those of us who spend too long with Windows, so I’ve been tinkering with an extra lite version! (I may well be installing SLAX on my venerable old ThinkPad 240 as well since it seems so flexible.)

Now that I have the LX1000 BIOS password, thanks to the very helpful Netvoyager customer support, I should be able to get it set up to boot back up after a power cut as well. Andy has also been asking about file serving but I haven’t given that a try yet. Plenty more to do!

Update: Another quick look at memory usage, this time after stopping a few unwanted services:

# free -t -m
             total       used       free     shared    buffers     cached
Mem:           116        100         16          0         17         62
-/+ buffers/cache:         19         97
Swap:           78          0         77
Total:         195        100         94