This morning we went to the funeral of our best friends’ father. It was, as funerals go, a lovely service and after the funeral and the burial we headed off to the wake, only to have someone’s hilux slam into the driver’s side of our car on a tight bend. They’d skidded and come onto the wrong side of the road by just enough, given the tight corner, to make the impact. Thankfully speed, alcohol or drugs weren’t in play, just the wet, and even more importantly, no-one was injured. Dignity will be lost any time it’s driven without a passenger though – the driver’s door can’t be opened from the inside:

Alas, poor car, I hardly knew ye

The case is with the insurers, and we’re waiting for an assessment next Tuesday to find out whether the car will be repaired or written off. It would be a shame if it’s written off; it’s a Toyota Avalon, circa 2001, and while those cars were frumpy they were damn good cars. With only around 120,000km on the clock it’s not really all that old. About 3 or 4 years ago it was almost completely totalled in a massive hail storm on the central coast; as I recall the repair was in the order of about $12,000, and it only scraped through for repair on an insurance value of around $14,000. Now, with insurance of $7,500 and the repair estimate saying that it’ll top $5,000, age is against the car and it doesn’t look good.

But, this blog isn’t about my hassles, or my car.

It is however about insurance, and insurance is something I’ll be dealing with quite a bit over the coming days. Or I will be, once we hit next Tuesday and the car gets checked out by the assessors.

When we think of “backup as insurance”, there’s some fairly close analogies:

  • Backup is insurance because it’s about having a solution when something goes wrong;
  • Making a claim is performing a recovery;
  • Your excess is how easy (or hard) it is to make a recovery.

Given what’s happened today, it made me wonder what the analogy to “written off” is. That’s a little bit more unpleasant to deal with, but it’s still something that has to be considered.

In this case I’d suggest that the analogy for the insured item being “written off” is one of the following:

  • Having clonesseems simple, but if one recovery fails due to media, having clones that you can recover from instead are the cheapest, logical solution.
  • Having an alternate recovery strategy – so for items with really high availability requirements or minimal data loss requirements, this would refer to having some other replica system in place.
  • Having insurance that can get you through the worst of events – sometimes no matter what you do to protect yourself, you can have a disaster that exceeds all your preparation. So in the absolute worst case scenario, you need something that will help you pay your bills, or ameliorate your building debt while you get yourself back on-board.

Of course, it remains preferable to not have to rely on any of these options, but the case remains that it’s always important to have an idea what your “worst case scenario” recovery situation will be. If you haven’t prepared for one, I’ll suggest what it’s likely to be: going out of business. Yes, it’s that critical that you have an idea what you’ll do in a worst-case scenario. It’s not called “business continuity” for the heck of it – when that critical situation occurs, not having plans usually results in the worst kind of failure.

Me? I’ll be visiting a few car-yards on the weekend to scope up what options I have in the event the car gets written off on Tuesday.

 

The much long-anticipated wait for LTO-5 is now approaching fulfilment, with stories such as “Mass Production of Sony LTO-5 Media Has Started” further reinforcing that this next generation enterprise tape format is about to start rolling into datacentres.

One of the biggest advantages of LTO-5 is that while the capacity has effectively doubled from LTO-4, we’ve not seen a comparable doubling in streaming speed. LTO-4 had a native streaming speed of 120 MB/s, which has caused more than a few headaches to backup administrators trying to keep it running at full speed. (Indeed, it’s an example of why I earlier posted “Direct to Tape is Dead, Long Live Tape“).

LTO-5, while moving to a native capacity of 1.5TB increases the native streaming speed by only 20MB/s – giving us a native streaming speed of 140MB/s. This still isn’t going to always be easy to achieve, but bearing in mind that each previous generation LTO technology has typically doubled the streaming speed of the one before it, 140MB/s is going to be a lot easier to integrate into the datacentre than 240MB/s would have been!

Looking at the generational specifications, we get:

LTO-1LTO-2LTO-3LTO-4LTO-5
Capacity (Native/Compressed)100 GB / 200 GB200 GB / 400 GB400 GB / 800 GB800 GB / 1.2TB1.5 TB / 3 TB
Speed (Native/Compressed)15 MB/s / 30 MB/s40 MB/s / 80 MB/s80 MB/s / 160 MB/s120 MB/s / 240 MB/s140 MB/s / 280 MB/s

Note – all compression sizes and speeds quoted at standard vendor estimate of 2:1 compression ratio. In reality, we all know that 2:1 compression ratios only occur on a small subset of data, and it’s usually better to estimate either a conservative compression ratio of 1.3:1, or if you want to be optimistic, a compression ratio of 1.4:1, unless you’re very certain that your data is highly compressible.

If you want to see these figures graphically, here we go:

LTO Ultrium Streaming SpeedsLTO Capacities

I’m not aware of the hard numbers, but anecdotally I’ve heard time and time again that a lot of sites have been reluctant to go up to LTO-4 from LTO-3 because they’ve not been ready to upgrade their infrastructure to support the streaming speed of LTO-4. Some have argued this is clear indication that LTO-5 will struggle for adoption. I beg to differ – while LTO-4 was effectively ahead of its time by a considerable margin, LTO-5 will instead enter a more sophisticated datacentre with better approaches to tape usage within the backup environment. In the cases of datacentres still using LTO-3, it will also be entering environments that are well an truly ready to upgrade their infrastructure. This article about HP’s strategy for LTO-5 that I was referred to this morning shows they have a similar vein of thought to me on this front.

The end result will be that a lot of sites that have stayed on LTO-3 will see good reason to make the step directly from that format up to LTO-5. The streaming speeds will only increase by just a little over double, but the native capacity will jump on those sites from 400 GB to 1.5TB – that sort of capacity increase will justify the expenditure required to hit the new speed target of LTO-5.

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