Archive for the 'Business' Category

Supermicro SATA DOM flash devices don’t report lifetime writes correctly

Saturday, November 26th, 2016

I’m playing around with a pair of Supermicro SATA DOM flash devices at the moment, evaluating them for use as the operating system storage for servers (as opposed to where customer data goes). They’re flash devices with a limited write endurance. The smallest model (16GB), for example, is good for 17TB of writes. Therefore it’s […]

Using a TOTP app for multi-factor SSH auth

Friday, May 6th, 2016

I’ve been playing around with enabling multi-factor authentication (MFA) on web services and went with TOTP. It’s pretty simple to implement in Perl, and there are plenty of apps for it including Google Authenticator, 1Password and others. I also wanted to use the same multi-factor auth for SSH logins. Happily, from Debian jessie onwards libpam-google-authenticator […]

Disabling the default IPMI credentials on a Supermicro server

Saturday, December 12th, 2015

In an earlier post I mentioned that you should disable the default ADMIN / ADMIN credentials on the IPMI controller. Here’s how. Install ipmitool ipmitool is the utility that you will use from the command line of another machine in order to interact with the IPMI controllers on your servers. # apt-get install ipmitool List […]

Installing Debian by PXE using Supermicro IPMI Serial over LAN

Friday, December 11th, 2015

Here’s how to install Debian jessie on a Supermicro server using PXE boot and the IPMI serial-over-LAN. Using these instructions you will be able to complete an install of a remote machine, although you will initially need access to the BIOS to configure the IPMI part. BIOS settings This bit needs you to be in […]

Supermicro IPMI remote console on Ubuntu 14.04 through SSH tunnel

Friday, November 13th, 2015

I normally don’t like using the web interface of Supermicro IPMI because it’s extremely clunky, unintuitive and uses Java in some places. The other day however I needed to look at the console of a machine which had been left running Memtest86+. You can make Memtest86+ output to serial which is generally preferred for looking […]

SSDs and Linux Native Command Queuing

Sunday, August 9th, 2015

Native Command Queueing Native Command Queuing (NCQ) is an extension of the Serial ATA protocol that allows multiple requests to be sent to a drive, allowing the drive to order them in a way it considers optimal. This is very handy for rotational media like conventional hard drives, because they have to move the head […]

F11 and F12 over serial

Friday, June 19th, 2015

I always seem to forget this one. To pass F11 or F12 over a serial connection (either real serial or Serial-over-LAN IPMI), it’s Escape followed by ! (Shift+1) or @ (Shift+’) respectively. Note that on a US keyboard ! and @ would be next to each other above the 1 and 2 keys so that […]

Fun with Supermicro motherboard serial headers

Friday, June 19th, 2015

or, “LOL, standards” TL;DR: Most motherboards have a serial header in an IDC-10 (5×2 pins) arrangement with the pins as a row of even numbered pins (2,4,6,8,X) followed by a row of odd numbered pins (1,3,5,7,9). Supermicro ones appear to have the pins in sequential order (6,7,8,9,X and then 1,2,3,4,5). As a result a standard […]

OneRNG kickstarter arrived!

Saturday, June 6th, 2015

My OneRNG kickstarter arrived today. I had five units, so I chose three external models and two internal ones. The finish of the external model isn’t really up to the quality of an Entropy Key. Here’s a picture of them together. Given that the external model looks rather flimsy — I could imagine it getting […]

Currently not possible

Sunday, October 12th, 2014

On Thursday 9th, after weeks of low-level frustration at having to press “close” on every login, I sent a complaint to Barclays asking them to stop asking me on every single login to switch to paperless statements with a dialog box that has only two options: This morning they replied: Please be advised that it […]