Author: frankd412

A lot of bit of nothing

December 19, 2014 / / 0 Comments

As it sometimes happens personal stuff has taken hold of my life and stopped me from doing anything major with anything technology related. I decided that I should pick a little project to pick up some new skills, so I’ll be setting up Cisco’s AIR-CTVM Wireless controller along with a couple LAP-1142Ns 802.11n (draft) access points that I picked up off of eBay to get rid of the DD-WRT APs which haven’t been entirely cooperative. For example, the Netgear WNR834B v2 will only use the base channel assigned with the second channel being two channels above it (currently channels 6 and 8) which is clearly not optimal for throughput.

I’m going to be rearranging my home network to segment it a bit more and do some more with routing. I want to keep the LAPs running off the 3560-24PS with PoE power instead of powering them with external bricks, so unfortunately each AP will be limited to 100mbit of throughput — that’s actually still better than what I get now over the 2.4GHz N AP, so it’ll still be a usable throughput improvement.

I’ll also be able to actually do some L3 segmenting instead of needing to share a VLAN across physical boundaries for the ‘dumb’ AP bridges currently in place.

I’ve been doing some work on IP management software, and while a lot of the back-end functionality is currently there for calculation, I’d like to rewrite some of it for speed. There are parts that are written strictly for readability using strings instead of bit compares, and they’re much slower than I’d like them to be for large address spaces. I should have something interesting to show if I can manage to put a little more time into it.

Another VM Host Upgrade

September 1, 2014 / / 0 Comments

And yet another not-exciting blog entry. My VM host with an FX-8320 was on an AMD 760G board so it lacked IOMMU which I’d love to have for SR-IOV among other things. I have a spare machine laying around that was formerly a gaming machine. Needing more RAM (The 760G board only had two slots) and IOMMU, I decided to repurpose the gaming machine as the VM host. The 990FX based board already had an FX-8120 in it, so I took a single step back in CPU generation but it’s fairly close. I only had 8GB of RAM in the old setup, so I combined that with 2x2GB sticks of ECC DDR3 RAM I had hiding in a box. I have a bit of head room now and can launch a few more VMs with 12GB of total RAM. While that’s not impressive as far as virtualization host hardware goes it does let me run a bunch of local services for testing/learning/re-learning. Not having onboard graphics with the new board necessitated the use of another video card, luckily I had some GTX 750 Tis laying around (I seem to lay ‘laying around’ about hardware pretty often) so one went in the bottom PCI-E x4 slot so as to not block any other slot for future upgrades. The Intel I350-T2 card went in the next x4 slot for iSCSI.

VM storage is going to be split off from the hardware, so it will all be through iSCSI with MPIO. That pretty much just leaves me with a ton of PCI-E slots for NICs.

I was able to reduce reported CPU TDP by offlining the “odd” cores (1/3/5/7) while load is low (better to offline these cores as 01, 23, 45, 67 are shared in AMD’s CMT architecture), locking the CPU at idle and reducing power state 6 (idle) voltage from 0.9375v to 0.825v which has been stable so far (sensors reports 0.85v). Power tends to stay close to 30w and never breaks 50w. If it was more heavily utilized I’d let it clock up, but nothing is CPU limited at the moment. I’ll have to try monitoring power usage at forced idle vs the ‘ondemand’ governor with various load transition points. I wouldn’t call anything sluggish, but I don’t have hundreds of devices on my network.

As for a power supply, the case already had a SeaSonic 660XP2 80+Platinum power supply, so even if I do have to run the CPU at full tilt there should be little waste in the PSU department. It’s completely overkill both for being Platinum at this power level (likely sub 100w at all times), and for its 660w rating. If I was going to buy something I probably would’ve got a SeaSonic Gold which would still allow me plenty of headroom even if it was full of NICs and RAM. It does feel a little safer than running off a 180w power supply with an FX-8320 and a drive array, though.

There’s plenty of local services running here, eventually I’m going to make some (counter)intuitive web GUIs for configuring stuff (ie IP Address Management which then configured DHCP/DNS).. so it was good to brush up on configuring these things from scratch.