CleverBlogName

The news that Apple is dropping ZFS does not greatly surprise me. While there's a lot of cheerleading around ZFS, some justified, some not, it would need a lot of work to play nice with the typical Mac customer. Apple brands on the whole "just works" thing. ZFS? ZFS is a bad fit for this. Consider some examples from Real Life on Solaris:

zpools grow, don't shrink

You can only ever grow zpools. Add disks or LUNs and decide you want to shrink again? Backup, destroy, start again. How intuitive is that? Can you imagine Apple explaining why you can dynamically expand your disk, but never shrink it to their "ease of use" customer base?

Don't cross the… fill the disk

Fill a pool to 100%? Oh dear. Oh deary me. You are about to discover an annoying, logical, and surprising property of ZFS. Since you write by appending changes, to ensure the atomicity of operations, you always need free disk to write proposed changes to the filesystem before you commit them. So if you need to delete some files to free up space in a full pool, you need to write some metadata before you... ahh, crap. Recommended fix? Backup, destroy, restore. Unless you're lucky enough to have some snapshots you can destroy, because they don't pre-commit metadata changes. They are the only thing you can remove that won't require preallocation.

The first time I encountered this behaviour I saw mailing lists with Sun engineers noting that the lack of an emergency reserve or some other mechanism to mimic the traditional reserve space created on filesystems in the Unix world was a bit of a design flaw, and the behaviour, while as designed, was shitty. They opined it ought to be fixed. In 2006.

Not exactly "just works", is it? "Just backup, destroy, and recreate your filesystem."

General Requirements

ZFS is hungry if you want it to work right. Various ZFS tuning guides I was reading in 2008 suggesed you can budget, depending on throughput, a half to a GHz of an UltraSparc VI[1] to drive decent performance if you use checksumming (which is a key selling point of ZFS). You ideally want a couple of gig for the ARC to get optimal performance, as well. If you're designing a server these are not likely to be requirements you think twice about. If you're buying a laptop or workstation you may have second thoughts.

Code Quality

I haven't looked at ZFS in a serious way in a year, so this may have cleared up, but back in 2008 I was stunned at how many kernal panic inducing faults were current in the then-current releases of Solaris 10u4 and u5. Add LUNs? Kernel panic. Remove LUNs? Kernel panic. Not all the time, of course, but there seemed to be a steady flow of hotfixes that were not what I'd expect from something being sold as an enterprise filesystem. I hope that's improved, but I can understand Apple's reluctance to deploy something which, on the face of it, had been pushed to market in a hurry (just ask Joyent!).

[1] A half-arsed metric, I know, but whatever.

A classic of bullshit headline writing, that is. "Oh noes!" thinks the punter, "one call while I'm driving could cost me my license!"[1]

Except, of course, it won't. One call and multiple cases of careless driving, speeding, or other offenses could cost you your license. If you keep getting caught, at best, breaking the law and, at worst, driving like a fucking idiot, you could lose your license. This is rather how the system is supposed to work—if you're paying so little attention you don't notice the police—that is, people in cars covered in day-glo stickers—watching you, you're probably not paying enough attention to notice pedestrians. Or cyclists. Or motorbikes. Or, for that matter, other cars and trucks.

[1] Punter would, one hopes, be more concerned that not paying attention to the task at hand, i.e. driving, could result in, you know, killing someone, but there seems to be an abundance of evidence this is not the case if one spends any time in traffic.

Art ho!

How to measure the success of an art exhibition in the eyes of a two year old? Well, Yayoi Kusama's previously mentioned exhibition has given me a pretty good yardstick: when Ada woke up this morning she declared that she wanted to "go to the art gallery to see the room with the water"—the Fireflies piece, which apparently ranks above even the yellow and black polka dot rooms and the "glowing room" in popularity.

And then a request to go see it again after the afternoon nap.

Ada is utterly hooked on the installations, and I like them too; I'm particularly pleased to see some of the ones I like best have been conceived in the last decade, as the sign of an artist who is continuing to be creative over the years. I suspect we'll be going back many more times over the four months the exhibition remains open.

There's something slightly odd about the sensation of watching the British Labour party overseeing strike-breaking. Part of that's obvious: a Labour Lord egging on the attempts to crush unionised labour is the sort of thing that could provoke not merely spinning in graves, but the rising of the dead. At what point, one wonders, does continuing to retain the Labour moniker become an act of gross dishonesty so barefaced that present generations of UK Labour pollies feels sufficiently embarrassed as to rename themselves?

The other part, though, is history: this is somewhat familiar. We don't have a House of Lords, of course, but our own Labour party went there more than two decades ago, with "Mad Dog" Prebble in the role Mandelson presently occupies. The British Labour party ought to consider how long the New Zealand version spent in the wilderness after it abandoned its base so thoroughly.

Went to see Yayoi Kusama: Mirrored Years at the City Gallery, and came away appreciating it as the most child-thrilling art I’ve been to in the last nearly 3 years. Starting from the gallery being covered in guant multi-coloured spots (which led to quoting of Put Me In The Zoo) through to the Narcissus Garden full of mirror spheres, the firefly exhibit of mirrors, water, and handing lights, and the favourite of the trip, the mini-maze of convex mirrors which lead to a yellow room with black polka dots and inflatable sculpture at one end, and a black room with yellow polka dots at the other end, it was a smash hit.

The only bummer was that photography was, as typical for exhibits, verboten, which means I wasn’t able to get photos of Ada’s near-unrestrained joy as she trotted from inflatable sculpture to inflatable sculpture in the polka dot rooms.

The oh-so-awesome HTFU:

On a more serious note (and Relevant to my Interests):

Father and Daughter

It’s the conversations I’ve never expected that throw me for a curve. How do you deal with:

Boy at birthday party: Can I share your daddy?
Ada: No, he is my daddy.
Boy at birthday party: But I don’t have a daddy.

Or when you’re chatting to a guy at a cafe you visit often, and he asks you what you’re doing with your daughter for the weekend. You tell him, and he says, “You sound like a good father. I wish my father had been as good a father as you.”