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Comment: Re:"internal traffic"? (Score 1) 329

by Craig Ringer (#40037733) Attached to: Comcast To Remove Data Cap, Implement Tiered Pricing

That was commonplace in Australia for some time, and worked really well.

WAIXMule was a modified eMule client that only used peers reachable via the Western Australian Internet Exchange (WAIX), which most WA ISPs didn't meter.

It worked too well; the ISPs started limiting traffic through peering points because of the congestion. Honestly, they weren't actually just whining, they had major trunk links being saturated. Upgrades would've been immensely more expensive because they were already the fastest economical links available, and had no benefit whatsoever for most users, so they started limiting peering point traffic. Fair enough, honestly.

Comment: Re:I can only speak for me... (Score 1) 329

by Craig Ringer (#40037691) Attached to: Comcast To Remove Data Cap, Implement Tiered Pricing

While this is currently true, in Australia we had both data caps and speed caps for a LONG time. It's only once Telstra's monopoly was broken by the advent of 3rd party DSLAMs in exchanges that this changed.

We're likely to see charges for both speed and data return with the NBN, at least according to the current pricing plans.

Comment: Re:Most won't notice (Score 1) 329

by Craig Ringer (#40037631) Attached to: Comcast To Remove Data Cap, Implement Tiered Pricing

I thought you were serious until the third and final sentence. Heh. A carrier thinking about long term network investment. Right. (OK, so the US has seen some of that actually happening, what with the Verizon fibre stuff, but it's pretty unusual).

For what it's worth, here in Australia a 100GB cap was considered very big until a year or so ago. Most people never knew or cared. Most plans were capped at 20GB or so, and people didn't know or care about that either. Of course, Australia doesn't have any useful streaming services; the existing ones are all geo-locked and nobody here seems to have the power to break through all the stupid media licensing to set up a local one. Unless you're a mad torrent freak, heavy gamer, or use a VPN to work heavily, even 20GB is usually overkill.

I want to laugh at people complaining about their constricting and horrible 300GB caps, but I'm aware the US market has tons of bandwidth-hungry services available that we just don't have equivalents of in AU, so it's not that comparable. Alas.

Comment: Re:Resolution (Score 1) 399

by Craig Ringer (#39950455) Attached to: Dell Designing Developer Oriented Laptop

While I'm a huge fan of portrait work and use a 1200x1920 portrait 24" display at home, I'll still take 1920x1200 over 1366x768 any day, and that's the choice I currently have.

Alas, Dell's Latitude models are one of the few laptops that have non-crap resolutions and decent touchpads instead of that horrible Alps crap everyone's using now. Pity Dell are marginally more evil than the other vendors at the moment (see, eg, the Optiplex affair).

Comment: Re:No they do more in shop kinds of testing (Score 1) 281

Plane crash tests - in so far as they are done - are thus more about making borderline situations more survivable. Not flying a perfectly good Airbus into the water at speed in a sustained stall, but ditching an airliner in the Hudson after ingesting geese and losing all power. Bringing one down on an abandoned runway turned speedway in a successful unpowered glide. Crash landing without main and/or nose gear without the aircraft breaking up or tumbling. Getting passengers off alive and quickly when an aircraft catches fire on the ground. Those sorts of situations DO matter; surviving a mid-air collision, break-up or controlled flight into terrain not so much.

Unfortunately they're so expensive to do that we tend to rely on investigation reports from the real thing to inform future design choices and suggest revisions. Important and great, but a lot could be learned especially about making aircraft water-ditchable and field-crash-landable by doing remote control crash tests. I suspect it isn't considered worth the cost.

Comment: Re:No they do more in shop kinds of testing (Score 1) 281

Crashes give you one important thing - things you never thought to test. This is true of both staged and real crashes. Controlled tests find out how much a plane can take; crashes help you find things to check for in controlled tests and new things to add to design guidelines.

Pity it is so expensive to crash airliners for testing.

Comment: Tape (Score 1) 141

by Craig Ringer (#39133021) Attached to: Why Corporate Cloud Storage Doesn't Add Up

OK, I've gone and looked into the current situation with tape. All prices are in AUD from vendors in Australia; 1 AUD = 1.06 USD at the moment, so they're close enough to the the same.

LTO-5 drives are now AU$2500 to AU$3000 + SAS HBA, a good year or two after I built that backup server. Most of our data set is data in formats that're already efficiently compressed with JPEG, LZO, PNG, deflate/zlib, etc, there's no significant compression gain; tapes can be presumed to be 1.5TB. The weekly hot set is over 1TB and the archives are over 5TB. We can probably pare the weekly down enough to fit it on a single LTO-5 along with the differentials, but we don't have tons of headroom. Library/loader units are AU$5k (sans tape drive) and up. Tapes are AU$80 or so, and shipping renders direct import no cheaper except in vast quantities.

Because of the cost of the LTO-5 drive it's just not worth it when you're only running a few tapes. We'd be better off with a fire-protected power-protected LTO-4 autoloader system. I've found one on end-of-line special at AU$4k down from AU$10k for 19TB of capacity (24 tapes), which is almost attractive. With LTO-4 tapes at about AU$55, that's a total of a bit over AU$5000 for library+tapes, or $263/TB, plus the controlling server. Still not exactly cheap.

Given that 1TB HDDs were down to below $100 ea, I could build a 10TB backup array (11 disks; 8TB usable; RAID6 + 1 hot spare) for about $1100 + enclosure. 4xSATA HBAs are less than $100 ea and putting three in a regular full-ATX or mini-ATX board is no big deal. Linux's software RAID (md) does a great job for this sort of thing, where write-through caching is acceptable because writes are mostly linear.

Given that we need the same kind of fire-resistant enclosures etc whether we're using tape or HDD, HDD wins by a mile.

If we were removing and rotating tapes daily then we might be able to get away without the fire protection. Maybe. The backups tend to run overnight with tapes exchanged in the morning, and that means there's a big window for loss before the tape gets taken away. Then there's the issue of finding someone trustworthy and reliable to exchange the tapes and, more importantly, not lose them.

As far as I can see, tape still loses unless you're doing LOTS of off-site archiving and have a large rotating media library. Even then it's tempting to just use HDDs in hot-swap caddies.

I don't think the economics support tape anymore.

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