Windows 7 as a QEMU-KVM guest

October 27th, 2012

While Windows 7 seems to run quite okay as a QEMU-KVM guest on my home server – which I will cover in another posting – there are a few things that I’ve noticed and that should be kept in mind when playing around with such setup.

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RRCP – Realtek Remote Control Protocol

October 27th, 2012

Recently during investigating some strange network packets sourced from my new D-Link switch when configured for “loopback detection” I came across “RRCP”, or “Realtek Remote Control Protocol” (ethertype 0x8899). I had never heard of it before, even though it seems to be quite interesting.

Basically it’s a protocol for configuring a network switch without the need of an embedded microcontroller usually used for displaying fancy web GUIs or telnet prompts. It works with Realtek chips RTL8316BP, RTL8318P, RTL8324P, RTL8316B, RTL8324, RTL8326 and RTL8326S that are often found in switches, even in cheap unmanaged ones. Depending on the specific type of switch this basically means – RRCP can sometimes be used to more or less turn a cheap unmanaged switch into a managed one, in some cases even without any hardware changes or with only minor changes such as soldering off a small SMD resistor.

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New switch – D-Link DGS-1100-16

October 27th, 2012

In order to improve my home network by increasing transfer speeds and adding new features I recently started to compare a bunch of small managed gigabit switches. My main criteria were that the device should have at least 10 ports, fanless operation, small device size, good feature-set, low power usage, long warranty and all that for a competitive price.

I quickly came across the D-Link DGS-1100-16, a 16 port switch that matched my expectations as mentioned above, and sells for about 120€ around here. Other vendors in this segment seem to prefer to sell huge 19″ devices even though the extra space within the device isn’t needed at all (Hello TP-Link?) or try to sell “managed” switches that are only “manageable” using some special Windows GUI software (Yes, NetGear, I’m looking at you).

See below for a short review of the D-Link DGS-1100-16 “16-Port Layer2 EasySmart Gigabit Switch”. Read the rest of this entry »

Harddrive load cycles

October 27th, 2012

I recently noticed a rather high “load cycle count” SMART value (“smartctl –all“) for my new harddrives that are only in operation for a few hours. Sure thing, I also heard the clicking noise of load-/unloading disk heads every now and then.

193 Load_Cycle_Count        0x0032   100   100   000    Old_age   Always       –       395

As the number of load cycles is somewhat limited – a rather high value, but limited nevertheless – over the lifetime of the disk I decided to disable the disk power management feature that caused these load cycles.

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S.M.A.R.T.

October 27th, 2012

I guess S.M.A.R.T (“Self-Monitoring, Analysis and Reporting Technology“) as used in harddrives is already well-known, therefore just a short reminder about its usage with Linux.

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