[ale] burning blu-ray discs

[Michael Trausch]

On 8/13/2014 3:06 PM, JD wrote:
> Guess I'm just confused by optical media these days. It isn't cheaper, isn't as
> convenient, it isn't re-writable 100,000x AND costs more than a spinning disk.

I use "normal" optical media for backups and data interchange. 
Write-once CDs and DVDs are pretty inexpensive to acquire and drives are 
ubiquitous.

The 25-pack of M-Disc BD-R for $130 is seemingly high-priced because 
it's a completely different composition. Whereas most other discs use 
dyes which break down over time, the M-Disc media are more like a layer 
of stone which gets etched as opposed to burned. Requires a higher power 
laser and all that jazz---but they essentially guarantee that the discs 
will retain data under normal storage scenarios for just about forever.  
I've heard that the military uses them as they apparently sustain field 
wear much better than other types of disc.

For normal single-layer BD-R I would expect to pay between $0.75 and 
$1.50 per disc right now. I managed to catch a hell of a sale at Fry's 
one time where I picked up tons of them for about $0.45 per disc, though 
I am starting to run low on them.

> I suppose if there are HIPPA or other regulatory requirements, but in a house?
> What am I missing?

Not sure I follow.

I use optical media for backups more or less like tape---I use DVD+/-RW 
(whichever is less expensive at the time, honestly) and those are good 
for 1,000 writes or so. That's not so bad when you're using 7 of the 
things each once a week. The only ones I've had "go bad" prematurely 
have been PEBDAC (problem exists between disc and chair) issues.  :-)

I don't faithfully use them all the time, but I backup frequently enough 
that I can always recreate my current state of work if necessary, 
without too much trouble. Anything that takes me more than 8 hours to 
download, I typically backup immediately. Anything that takes more than 
a couple of days to download, I *always* backup immediately.  :-)

> BTW, I have over 1,000 backup DVDs here (mix of 4.7 and 8G) ... but stopped
> using optical when HDDs became less expensive.  Slowly moving those to 2+TB HDDs
> that can be connected via a USB3 dock.
>
> Can someone please enlighten me?
It's far more likely that your physically-smaller and less expensive HDD 
is going to take all of its bits away at once and cripple you far more 
heavily than the loss of a few optical discs (and even then, you can 
usually read 98% of the data off of the optical disc, unless you've 
shattered it or damage exists in critical areas of the track).

Of course, in a house fire it's easier to grab the HDD, so maybe the HDD 
is a good *addition* to your backup regimen, but I wouldn't replace the 
optical media at all.  Maybe change the way you use the optical media to 
make it more cost-effective, though; I prefer a rotating backup schedule 
with RW media, and then periodically very large ("level 0") backups to 
write-once media. For those, I use a program called splitpipe to create 
the dumps, and joinpipe when I have to read (or verify) them.

Otherwise, I more or less attempt to back everything up soon after 
wrapping up with it, and on a schedule of sorts. (I backup my ~/Projects 
directory more than any other, typically about once per week.) I don't 
use fancy scripts or anything just yet. I've tried things like rsnapshot 
and so forth, which work OK, but I like tighter control.

It's time for a backup system to come out with native support for btrfs. 
A single well-placed component like that, and all backups (from the 
point of view of application uptime) only take 30 seconds... but now I'm 
way off-topic.

     --- Mike
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