I needed to do something about the Mac minis that were accumulating on the table in my office. Digging around, I found this Rubbermaid organizer on Amazon.

It turns out to be nearly perfect. The unit is very sturdy, was easy to put together, and the shelf height is just right. There’s enough clearance for airflow but not so much that you feel space is being wasted.

I used self-stick cable tie anchors and cable ties to mount the power bricks and used double-stick mounting tape as stops to keep things in place. The old-style minis are heavy enough and are pretty non-slip, so I just put some tape at the front of the shelf to keep them from sliding off. The one new-style mini was pretty slippery so I used the tape to actually stick the base to the shelf.

The unit came with vertical rods that go in the back of each column of shelves to keep them from sliding out the back, but I decided to leave those out. That way I can slide each shelf forward to get DVDs into the mini, or back to get at the connectors.

The weak spot of the minis is the power cord (at least on the pre-2010 models) which comes out quite easily. I tied those down as well and am pretty sure they won’t jiggle their way out. I have four minis in the rack right now along with a Drobo with 10TB of disk. I’m going to be adding a 5th mini with a stackable disk drive, that’s why there’s double-high slot  still open on the mini side of the rack.

Cable management is an issue, mostly because of the power bricks long cables. I may fiddle with how I fold the cables into the shelves a bit more.

The whole thing plus a UPS and monitor/keyboard/mouse sits nicely on some steel shelves in our A/V equipment room at the museum. I still need to time how long the UPS runs. I’m only going to have the public web site minis on it.

I moved this blog from one of the Mac minis in my basement to the other (I’m trying to put everything on the newer one to free the other one up) yesterday. Originally I had been blogging using Plone (from about 2005-2007) and then moved to WordPress. Moving the Plone part seemed like it was more work than I wanted to put in, so it’s goodbye to those posts.

I had seen this tidbit that Sean Gillies writes about in the recent OGC newsletter. My thoughts were along the lines of Sean’s. I never understood the big deal behind URNs.

EDIT: Forget the semi-rant, see the comments, and then go read about URI…

But in re-reading Sean’s post and the OGC news coming out of the June 2010 meetings, I think the terminology is a bit imprecise. Too bad the source document, 10-124r1 isn’t available on the OGC web site (promised for mid-July, I see) to see if the issue is in the document or in the news page. Here’s the news page version:

OGC Identifiers – the case for http URIs’

The OGC Members approved release of ‘OGC Identifiers – the case for http URIs’ [OGC 10- 124r1] as an OGC Whitepaper. .According to the current OGC policy either URNs or http URIs may be used in OGC standards. However, the use of http URIs (a) resolves some deployment challenges and (b) provides an opportunity for easier engagement with broader communities. So OGC should now consider taking the next step, and mandate the use of http URIs for persistent identifiers in OGC specifications. This whitepaper canvasses a number of issues around this proposal.

http URI Policy

The OGC Members approved the following as official OGC policy to be included in the OGC Policies related to OGC standards [OGC 06- 135rN]:

• OGC TC directs the OGC-NA that all new OGC identifiers issued for persistent public OGC resources shall be http URIs, instead of URNs
• New standards and new major versions of existing standards shall use http URIs for persistent public OGC resources to replace OGC URN identifiers defined in previous standards and versions, unless OGC- NA approves an exception

Operational Implications: OGC should carefully manage (maintain for the long term) the http://www.opengis.net domain and identifiers in this domain

So what’s wrong? Refer to RFC3986 (or the html version). Section 1.1.3 talks about URI, URL, and URN:

A URI can be further classified as a locator, a name, or both. The term “Uniform Resource Locator” (URL) refers to the subset of URIs that, in addition to identifying a resource, provide a means of locating the resource by describing its primary access mechanism (e.g., its network “location”). The term “Uniform Resource Name” (URN) has been used historically to refer to both URIs under the “urn” scheme [RFC2141], which are required to remain globally unique and persistent even when the resource ceases to exist or becomes unavailable, and to any other URI with the properties of a name.

A URN is a kind of URI. What is called an “http URI” is really a “just” a URL in RFC3986. And, a URN need not (or I should say “need no longer”) be something with “urn:” in the scheme. A URL could be a URN based on the last part of the definition above, “any other URI with the properties of a name”

Therefore, an “http URI” (from the OGC wording) can be either a URL or a URN, based on section 1.1.3 of RFC3986. Of course, the URN is really a URL with the additional uniqueness and persistence properties. So let’s just call OGC’s newly mandated URIs URLs.

There are two primary motivations for using RFC2141 URNs. One is as a globally unique name managed by some authority. The other is as a persistent identifier, sometimes used to map onto a URL with a resolver. The trouble with the latter is that URLs really work better in the first place, and I’m guessing that’s what 10-124r1 says.

So here’s what I think they should have said in the TC:

URI Policy

The OGC Members approved the following as official OGC policy to be included in the OGC Policies related to OGC standards [OGC 06- 135rN]:

• OGC TC directs the OGC-NA that all new OGC identifiers issued for persistent public OGC resources shall be http URLs, instead of RFC2141 URNs
• New standards and new major versions of existing standards shall use http URLs for persistent public OGC resources to replace OGC RFC2141 URN identifiers defined in previous standards and versions, unless OGC- NA approves an exception

Sorry to be so pedantic. Back in the day, there would have been half a dozen people at any given TC who would have been able to argue the finer points of this for hours….

(And I just figured out what the OGC-NA is. I guess it’s the “Naming Authority”.)