Jul 302018
 

Alternatively, why does Windows use drive letters? Because if you are coming from an old unix background, drive letters are just as weird as the lack of them if you are coming from a Windows background.

I mean, why is Windows installed on drive C? What ever happened to drives A and B?

Technically Linux does have the equivalent of drive letters but they are rarely used directly (unless you’re weird like I am). For example I currently have an SD card plugged into my desktop system, and it has the path /dev/disk/by-label/EOS_DIGITAL (or /dev/sdo1).

Historically, Unix (which is loosely the predecessor of Linux) ran on large minicomputers where system administrators would decide what disks were “mounted” where.  The Linux equivalent of drive C is effectively “/” (root), and you can attach (or “mount”) disks at any point underneath that – for example /home.

This allowed people to use an old Unix machine without worrying where this disks were; and allowed system administrators to add and remove disks as and where they were needed. These days we are all system administrators as well as users – that little voice you hear from time to time saying things like “When would be a good time to update the operating system?” and “I must clean up those temporary files all over the place” are your inner system administrator speaking up.

And if you don’t hear that inner voice, cultivate it!

With device paths, Linux has the opportunity to create sensible friendly names for disks, but a historical accident has resulted in almost every kind of disk being identified as a SCSI disk – SATA disks (a normal hard disk), SAS disks (server hard disks), Fiber Channel disks (SAN hard disks), and even USB storage devices all use SCSI commands.

So nearly all Linux disks are identified as /dev/sd followed by a letter (a “drive letter” – we can’t get away from them) and a number indicating the partition. Fortunately there is also the relatively new /dev/disks directory that has slightly friendlier names for disk devices. If you are getting into low-level disk management, learn these directories; in particular if you are looking into enterprise disk management look at WWNs (each disk has a unique “world-wide-number”).

Now back to Windows. Windows is the descendent of DOS, which goes back to the time when PCs may not have had hard disks and by default would have booted off a floppy disk in drive A with a data disk in drive B. Later PCs came with hard disks which used drive C on the assumption that you would have one or two floppy drives.

Windows has been updated over the years and there is a great deal of sophistication under the surface, but it does act a bit conservatively when it comes to drive letters – A and B are by default reserved for floppy drives even though I haven’t seen one of those on an ordinary system for years. You can use A and B for other purposes such as mapping network drives – A makes a good drive for a NAS drive.

If we get away from the terminology of “drive letters” and “device paths” and instead refer to them as “storage device names”, both Linux and Windows have “storage device names” but Linux prefers to hide that level of detail.

Personally I prefer the Linux way, but whatever floats your boat.

Jul 292018
 

Second Best Bench

What seems like a long time ago (2006), I picked up a cheap Canon DSLR for a bit of fun, and surprisingly enough found it fun. What was even more surprising was that this picture was the first that indicated that perhaps some of the images I made were not entirely bad. And I have just heard that Getty have picked this image up (via EyeEm) to sell.

Jul 242018
 

As someone who has spent far too much time dealing with the Domain Name System, I get kind of miffed when people insist on creating names that conflict with the DNS ordering. You see the DNS naming works from right-to-left (the wrong way around if you’re reading this in English).

Take the name for this site – really.zonky.org – which is admittedly a rather quirky name. The most significant part of the name is at the right (org – and yes I’m ignoring the really significant and invisible “dot”). The next most significant part (zonky) specifies what organisation has registered the site (me), and the least significant part (really) points to one service at that organisation.

So when people ask for names that break that ordering it is ever so slightly irritating – for example if you have a service called mail.zonky.org and wanted a test service you might request mail-test.zonky.org which breaks the ordering of things. As an alternative, test.mail.zonky.org doesn’t break the naming, looks a bit nicer, and ultimately more reasonably flexible.

Let us look at a slightly more complex example; let’s assume that we have a domain called db.zonky.org and want to register a service name for each database. We could register names such as db-addresses.zonky.org, and db-orders.zonky.org, or we could register them instead as addresses.db.zonky.org and orders.db.zonky.org. In the later case, I can very quickly write a firewall rule that allows access to *.db.zonky.org (whereas db-*.zonky.org would not work).

Ultimately suggest names in DNS naming order unless you can justify why it is not suitable.

 

Jul 142018
 

Liam Fox has claimed that Trump protesters have “embarassed” themselves by protesting Trump’s visit to the UK. He claims that we have a tradition of being polite to guests (at least until they throw up on the carpet, piss in the wine, and try to have sex with the host).

Well, I didn’t invite that jumped up rancid little toad who is Putin’s lickspittle and quite possibly the closest thing we’ve seen to a major free world leader being a Nazi. So I am under no obligation to be polite to the bankrupt crook.

Besides which, with his unreasonable and unhinged attack on NATO, Trump has been pissing in the wine, so it would not be unreasonable to slam the door in his face. Of course I’m not being “diplomatic” but I’m not a politician so I’m not being paid to be polite to the kind of person resembling that which you instinctively scrape off your shoe.

To USians who might feel a bit insulted by how their president is being treated; well if you did your job properly and didn’t elect someone with the brains of a pea-sized petrified panda turd who separates children and puts them in concentration camps then we might treat them with a bit more respect.