The 2920 series switches from HPE/Aruba has a special feature that no other switches in the old ProCurve/E-Series line-up has; dedicated stacking interfaces. On other HPE switches, stacking merely facilitates “simplified” management, by allowing you to manage any switch in the stack from the stack commander’s CLI. On the 2920 series however, you can use dedicated stacking interfacing, giving you 2 20 Gbps links to other switches in the stack and merging two to four switches into one coherent switch. This is quite similar on how stacking works on some Cisco models, but the specialized stacking interfaces gives you higher speeds between the members. In this article, I’ll show you have to set up the commander switch and how to add switches to the stack once it’s created. I’ll also go into how it affects the configuration of the switches, which is quite crucial if you want to stack switches that are already in production.
So, you guys seem to have liked my Techniworm Mochamaster tutorial (I won’t lie, that article outperforms every other article on this site by a factor of 10). I started thinking about what I could write next, and it occurred to me, the French Press! Second only to espresso, French press coffee is among the most horribly mangled and mistreated coffee you come across in cafés worldwide (not counting Greece, what they do with instant coffee there is too horrible to even contemplate). A lot of it stems from the usual suspect, cheap and stale pre-ground coffee, but some places put a lot of effort into their FP (french press) coffee, and it still comes out tasting like industrial sludge. So, since I’ve been studying this brewing method for quite some time, I thought I’d share a bit of technique or two that I’ve picked up over the years that really makes a difference.
A couple of years ago a bought a Royal Balance Syphon brewer, and I made a video of how it works. It’s the oldest design for an automatic coffee machine, invented in the 1840’s by the Frenchman Louis Gabet. and basically does the all the same things as your modern Moccamaster, except heat the coffee after it has finished brewing. Sadly my machine’s tin coating of the copper boiler has eroded away over the years, rendering the coffee it makes undrinkable, but it’s still a nice piece of semi-functional art.
If you’re interested in how to actually use one, here’s a short instruction; the ratio of coffee to water is the same as for any other coffee maker, approximately 60 grams of coffee to every litre of water. I used half a litre of water in the video, and 30 grams of coffee. I’m not 100% sure of the optimal grind for it, but considering the short brewing time (which is suboptimal) you’d want something similar as to what you use in your drip brewer. As you can see in the video, I use preheated water from a kettle, and I urge you to do the same, the boiler takes around 10 minutes (which I cut out of the video) to build up enough steam to push water into the brewing vessel when you start with water just off the boil. Starting with cold water would probably take longer than you’d fancy waiting for coffee.
I’ve been doing Sous Vide cooking for a couple of years, and every time I cook something, I go online searching for proper cooking times and temperatures.
Today, while cooking some lamb tenderloin for Easter, it dawned on me that I quite frequently look up the times and temperatures for cuts I’ve already cooked several times with good success, which is quite redundant and doesn’t give me consistent results. So, hereafter I’ll post the times in this blog post, giving me a place to maintain the information, and another good reference for the rest of the world.
For the last couple of weeks, I’ve been playing around with a FreeBSD distribution that’s quite interesting, FreeNAS. FreeNAS basically turns any old box you have lying around into a NAS, though you should definitely not run it on any old box. The only problem was, I got a bit excited when setting up my system, so I configured a RAID-Z vdev for my zpool. Technically, this was not an issue at the time when I set up the pool, since I was using old leftover 160GB and 250GB drives. But after a while I replaced the 160GB drives with two 1 TB drives I had laying around. And a couple of days later, I ordered 2 4TB drives to replace the 250GB ones. And then RAID-Z started to be a problem. You see, RAID-Z suffers from the same problems as RAID5, aka. that if you set up an array with large SATA drives (1 TB or larger), and one drive fails, you’re almost guaranteed a bad day (if you’re not running enterprise grade drives, more on this later in a separate post). So before I went and installed the new drives I migrated my whole pool to a backup drive and destroyed the old vdev and pool. Here’s a short guide on how I, relatively successfully did it. Continue reading
I recently had to do a reinstall of Windows 10 on a 3 year old Lenovo desktop. I previously updated the machine from Windows 7 to Windows 10, and shortly thereafter the hard drive started to give intermittent issues, so I decided to upgrade the machine with a SSD and do a clean install of Windows 10 at the same time. Turns out, installing Windows 10 from scratch isn’t that easy, so here are some of the things I discovered while researching the issue.
Now that Google has released version 45 of Chrome the NPAPI enable-trick that I showed you a couple of months ago has finally stopped working. The good news is that VMware has fixed the whole issue in vCenter 6.0 Update 1. So as long as you update, you’ll be fine. And if you want to continue using vCenter 6.0, they have released a new Client Integration Plugin (CIP) that works with vCenter 6.0.
But, the bad news is that the new CIP doesn’t fix compatibility with older versions of vCenter, for example 5.1 and 5.5, which I’d wager is still a sizable part of the VMware vSphere installations out there. There’s a fix promised coming within a short while, but since Google has been threatening with retiring NPAPI for 2 years now, I would not hold my breath for a quick resolution.
The best course of action at the moment is to switch browsers if you need the special features provided by the CIP, provided that you haven’t updated to vCenter 6.0 already. Keep in mind that the CIP also has some issues with Mozilla Firefox starting from version 39 onwards, but they can be fixed by flipping some flags.
This past week I had a gig to photograph some promotion shots for a local band here in Helsinki. Their gig was quite long, and I had to wait until the very end to do some arranged shots, so I had a lot of time to experiment. After taking all the shots I needed, it though it might as well take some video, since I had brought my new tripod (Manfrotto BeFree, review coming up shortly).
Since I’m not that familiar with video editing and Youtube, if quickly ran into a problem, how loud should I make the audio in the video? After rummaging around on Google for a while, I found an excellent post on the subject by Kevin Muldoon. Long story short, you should normalize the peaks in the audio to -1 dBFS, and set background music at least 20 dB under overlaid speech.
Since this was quite useful information, and I had to rummage around a bit more on the InterTubes to find how to do this in Adobe Premiere, I thought I’d go full meta and post a Youtube video about it!
If you have experienced a problem with the vSphere Client Integration Plug-In not working even though it’s installed in Google Chrome, you’re not alone. Seems like Google decided to disable NPAPI (Netscape Plugin Application Programming Interface) from version 42 of Chrome onwards. The vSphere Client Integration Plug-In (henceforth known as the plug-in) utilizes the NPAPI to interact with Chrome, and Google is currently trying to phase out that particular API. The name should give you an idea of the age of that particular API (youngsters, go google Netscape and prepare to be amazed), and Google’s reasons for retiring it are quite understandable. VMware, on the other hand, are as usual quite tardy when it comes to supporting changes to Chrome, so it might be a while before we will see a new plug-in supporting a newer API.
If you’re anything like me, you like to get things up and running fast. And this means doing a bare minimum configuration of a new switch so you can get to testing connectivity as soon as possible.
So, what do you do? You boot the switch, give it a hostname and a some basic security settings, and then you configure the management VLAN and give it an IP address. After that you configure the trunk interface and try pinging the switch from another device. And everything fails. And you tear out your hair trying to figure out what’s wrong. And finally, after what feels like a lifetime (in reality about 2 minutes), you try pinging something else in the network from the new switch. And it works perfectly.