OT: archiving on CD/DVD
N_Cook
http://news.bbc.co.uk/1/hi/programmes/click_online/8711747.stm
Using apparently high spec discs is no guarantee of longevity.
Mention of what I happen to do, copy 3 yearold backups to new on a rolling
basis and keeping in 2 different sites for storage. I also check originals
at the same time for any degradation. No mention of writing at reduced speed
for archiving purposes. I happpen to always knock down from x52 to 40 for
normal burning (slightly larger pits) and then x32 for 3 yearlt archives.
French researcher shown cleaning dics radially , not circumferentially.
Shame BBC reporter did not mention this factor.
Anyone else got any tips ?
--
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http://diverse.4mg.com/index.htm
Meat Plow
> BBC click this week did a feature
> http://news.bbc.co.uk/1/hi/programmes/click_online/8711747.stm Using
> apparently high spec discs is no guarantee of longevity. Mention of what
> I happen to do, copy 3 yearold backups to new on a rolling basis and
> keeping in 2 different sites for storage. I also check originals at the
> same time for any degradation. No mention of writing at reduced speed
> for archiving purposes. I happpen to always knock down from x52 to 40
> for normal burning (slightly larger pits) and then x32 for 3 yearlt
> archives. French researcher shown cleaning dics radially , not
> circumferentially. Shame BBC reporter did not mention this factor.
> Anyone else got any tips ?
What are you archiving?
hr(bob) hofmann@att.net
> BBC click this week did a featurehttp://news.bbc.co.uk/1/hi/programmes/click_online/8711747.stm
I bet you use a belt and suspenders too. Seriously, I think what you
are doing requires more discipline than most of us mere mortals
have.<G>
Sjouke Burry
Much less expensive, and flexible too.
Also fine for an image backup of the system disk(and fast restore).
I use Paragon(free for private use) and Ghost2003.
Grant
>BBC click this week did a feature
>http://news.bbc.co.uk/1/hi/programmes/click_online/8711747.stm
>Using apparently high spec discs is no guarantee of longevity.
>Mention of what I happen to do, copy 3 yearold backups to new on a rolling
>basis and keeping in 2 different sites for storage. I also check originals
>at the same time for any degradation. No mention of writing at reduced speed
>for archiving purposes. I happpen to always knock down from x52 to 40 for
>normal burning (slightly larger pits) and then x32 for 3 yearlt archives.
I think still too fast ;) Here I use 24x for temp life (6 months) disks.
Archival is multiple copies on hard drives, migrated as I retire drives
for larger ones.
>French researcher shown cleaning dics radially , not circumferentially.
That's always been true, if you clean in circles you create scratches longer
than what the error correction can cope with.
Grant.
--
http://bugs.id.au/
Dave Platt
Grant <o...@grrr.id.au> wrote:
>I think still too fast ;) Here I use 24x for temp life (6 months) disks.
Another trick you can use is to apply an additional level of error
correction, with e.g. the "dvdisaster" package. You create an ISO
image of up to about 85% of the maximum for your chosen disc type, run
it through "dvdisaster" to create a set of Reed-Solomon checksums and
append them to the ISO, and then burn the resulting enlarged ISO to
the medium.
If, when you try to read back files from the disc, you find some
sectors unreadable due to damage or deterioration, you can tell
dvdisaster to read as much of the disc as it can, and then use the
added Reed-Solomon codes to recover the contents of any sectors which
weren't readable. The resulting repaired ISO can be burned to a new
disc, or (on Linux at least) loopback-mounted to allow files to be
retrieved directly.
--
Dave Platt <dpl...@radagast.org> AE6EO
Friends of Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
b
> BBC click this week did a featurehttp://news.bbc.co.uk/1/hi/programmes/click_online/8711747.stm
> Using apparently high spec discs is no guarantee of longevity.
I have lots of CD-Rs created in 2000, which are unplayable. Expensive
audio CD-Rs at that. Stored on a shelf at room temp, boxed, rarely
used. also had a few DVDs warp - princo ones mostly, which seem to be
two plastic discs stuck together.
forget optical media for archiving. I use external HDD. Also audio
tape which has stood test of time.
-B
D Yuniskis
> BBC click this week did a feature
> http://news.bbc.co.uk/1/hi/programmes/click_online/8711747.stm
> Using apparently high spec discs is no guarantee of longevity.
> Mention of what I happen to do, copy 3 yearold backups to new on a rolling
> basis and keeping in 2 different sites for storage. I also check originals
> at the same time for any degradation. No mention of writing at reduced speed
> for archiving purposes. I happpen to always knock down from x52 to 40 for
> normal burning (slightly larger pits) and then x32 for 3 yearlt archives.
> French researcher shown cleaning dics radially , not circumferentially.
> Shame BBC reporter did not mention this factor.
> Anyone else got any tips ?
Depends on what you are backing up and how important it is to
you. :-/
I backup on several different *types* of media concurrently.
CD/DVD, MO, hard disks and tape. Each medium has different
risk issues.
I won't *rely* on a hard disk as a backup medium. It's just
too easy for a single spindle failure to cost you a *lot* of
data! Even having *two* backups on hard disks doesn't guarantee
you are "safe"
[The only time I *almost* lost data was using hard disks as the
backup medium. The backups were stored "off line" (i.e., not
powered). I went to retrieve something from my "primary"
backup -- only to discover the disk *scrambled* (VTOC). I
frowned but figured a hard disk failure is something you
*eventually* have to deal with... So, I pulled my *secondary*
backup out and spun that up. And it, *too* was scrambled!
(I later discovered this was a drive-aggravated bug in the
driver so *every* drive of this make/model would end up
scrambled!). Thankfully, I had the DRIVES backed up on MO
media as well and was able to restore from that -- though it
obviously took a bit longer as the MO media wasn't as big as the
hard disk]
My current practices are to *push* things that I want to
backup onto one of my servers "whenever it is convenient".
Then, periodically backup to tape (SDLT), an external USB
drive and CD/DVD.
I have maintained some items for more than 20 years using
this technique -- though it gets more and more expensive (time)
as my archive grows.
Best advice: decide what things you are willing to "lose";
then ask yourself, "If I am willing to lose it, is there
any reason why I shouldn't (deliberately!) lose it *now*??"
N_Cook
news:08afbe42-0330-4680...@k31g2000vbu.googlegroups.com...
wwwwwwww
Is there an issue with plastic stored in plastic?
I've only used CDrom storage since 2002 . Always stored in plain paper
envelopes, no glue , stored vertically and none that I've randomly tried
files have had a reading problem
Arfa Daily
"N_Cook" <div...@tcp.co.uk> wrote in message
news:htu8gf$d49$1...@news.eternal-september.org...
Discs should be cleaned radially ...
Arfa
vjp...@at.biostrategist.dot.dot.com
I had scanned most of my personal documents, including microfilm of
all my college notes. I am not too happy with any media. The twenty
year old microfilm had started to decay. ANd I am spooked by the
IoZip click of death. I have "gold" CDs for my archives.
But a 10MB HD I have in the basement from 1985 still works fine.
- = -
Vasos Panagiotopoulos, Columbia'81+, Reagan, Mozart, Pindus, BioStrategist
http://www.panix.com/~vjp2/vasos.htm
---{Nothing herein constitutes advice. Everything fully disclaimed.}---
[Homeland Security means private firearms not lazy obstructive guards]
[Urb sprawl confounds terror] [Phooey on GUI: Windows for subprime Bimbos]
vjp...@at.biostrategist.dot.dot.com
*+-I backup on several different *types* of media concurrently.
*+-CD/DVD, MO, hard disks and tape. Each medium has different
*+-risk issues.
Excellent strategy - engineering redundancy.
ON HD: I have a system with batch files which backs up files on the
same disc. More often than not, that is what is really needed in case
of human error. I also wonder if it is worth saving the ISO of a
backup CD or DVD and accessing it via CDanywhere.
ON Tape: I'm surprised to hear this. Back in the 1970s if i played a
two year old cassette it had a buzz to it. But that may be some
problem caused by the microphones and interference.
Meat Plow
Was just browsing a CDR I made in 1999. Have some audio CDR from around
then that I listen to on occasion. Odd that your discs didn't last 10
years. I have some that I created with my 1x HP SCSI burner back in the
mid 90s that still read fine.
Jeffrey D Angus
> Best advice: decide what things you are willing to "lose";
> then ask yourself, "If I am willing to lose it, is there
> any reason why I shouldn't (deliberately!) lose it *now*??"
Oh yeah, definitely. Periodically I get the "urge" and act
like your typical B-movie crazed ax murderer and clean house.
Jeff
--
�Egotism is the anesthetic that dulls the pain of stupidity.�
Frank Leahy, Head coach, Notre Dame 1941-1954
D Yuniskis
> *+-I backup on several different *types* of media concurrently.
> *+-CD/DVD, MO, hard disks and tape. Each medium has different
> *+-risk issues.
>
> Excellent strategy - engineering redundancy.
>
> ON HD: I have a system with batch files which backs up files on the
> same disc. More often than not, that is what is really needed in case
> of human error. I also wonder if it is worth saving the ISO of a
> backup CD or DVD and accessing it via CDanywhere.
What you have to be wary of is having *some* bad spot on the medium
(whatever that is) -- or the *image* of the medium -- causing you to
*lose* the entire contents of the medium! I.e., error codes can't
reconstruct "big holes".
> ON Tape: I'm surprised to hear this. Back in the 1970s if i played a
> two year old cassette it had a buzz to it. But that may be some
> problem caused by the microphones and interference.
The problem with tape is you have to "retension" it periodically
in order to avoid print-through. But, with (S)DLT, that's pretty
easy to do just in the normal course of *using* it.
Michael A. Terrell
Jeffrey D Angus wrote:
>
> D Yuniskis wrote:
> > Best advice: decide what things you are willing to "lose";
> > then ask yourself, "If I am willing to lose it, is there
> > any reason why I shouldn't (deliberately!) lose it *now*??"
>
> Oh yeah, definitely. Periodically I get the "urge" and act
> like your typical B-movie crazed ax murderer and clean house.
Or just move half way across the country. ;-)
--
Anyone wanting to run for any political office in the US should have to
have a DD214, and a honorable discharge.
Franc Zabkar
finger to keyboard and composed:
>Anyone else got any tips ?
I make it a policy to fill up the entire CD, if only with redundant
copies.
For example, let's say you have 100MB of photo files. I'd copy these
same files to 7 directories, ie COPY_1, COPY_2, ... COPY_7. That way
you have 7 chances to recover your precious snaps in the event of
physical damage, CD rot, unreliable burner, unreliable media, etc.
- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.
Grant
>On Sun, 30 May 2010 18:51:44 +0100, "N_Cook" <div...@tcp.co.uk> put
>finger to keyboard and composed:
>
>>Anyone else got any tips ?
>
>I make it a policy to fill up the entire CD, if only with redundant
>copies.
>
>For example, let's say you have 100MB of photo files. I'd copy these
>same files to 7 directories, ie COPY_1, COPY_2, ... COPY_7. That way
>you have 7 chances to recover your precious snaps in the event of
>physical damage, CD rot, unreliable burner, unreliable media, etc.
Burn slow and verify too, works for me :)
Grant.
--
http://bugs.id.au/
Charlie
What everybody seems to key onto is the useful life of the media,
What might be more of a problem is the useful life of devices to read that
media.
Case in point. A friend who runs a small shop called and wanted to transfer
her business file to a new computer.
The stumbling point was that the media was 5.25 inch floppies.
Don't bother criticizing her for being stuck with an obsolete system.
Consider tape backups or even 2.5 inch floppies.
Ten years will those carefully preserved CDs been totally replaced by (fill
in the blank with your guess and bet your data on it).
Charlie
D Yuniskis
Charlie wrote:
> What everybody seems to key onto is the useful life of the media,
Because once the media is toast, there's nothing more you can do.
> What might be more of a problem is the useful life of devices to read that
> media.
>
> Case in point. A friend who runs a small shop called and wanted to transfer
> her business file to a new computer.
> The stumbling point was that the media was 5.25 inch floppies.
> Don't bother criticizing her for being stuck with an obsolete system.
>
> Consider tape backups or even 2.5 inch floppies.
>
> Ten years will those carefully preserved CDs been totally replaced by (fill
> in the blank with your guess and bet your data on it).
<grin> Keep lots of spares! (I have 5 or 6 DLT transports, and no
fewer than 2 or 3 of every other "drive" -- even 8" floppies! :> )
Making backups (that you actually expect to be able to use!)
is a costly undertaking.
N_Cook
pre-existing statement on my tips files
"Cleaning CDs, DVDs etc
Always clean
data/audio or video CDs in a radial sense, not circumferentially, so that
any microscratches are across and not along the data paths."
William R. Walsh
> I happpen to always knock down from x52 to 40 for normal burning
> (slightly larger pits) and then x32 for 3 yearlt archives.
Go more slowly than that, on the order of 4X/8X burns if you want
longevity.
I store my discs in a dark, cool and dry place on shelves in their
cases.
So far the best longevity I've seen is from paper, hard disks, CDs,
QIC80 backup tapes or even carefully stored floppies, in that order.
I was really a little astounded when I unearthed some QIC80 cartridges
and found that nearly all were readable. Only one was not, and it was
because the tape had rolled into the cartridge. It could probably have
been fixed. Of course, the QIC drive is so simple, and as long as the
rubber drive roller is good, it ought to work.
In my experience, DDS and SDLT tapes have proven to be unreliable even
after as little as three years of storage.
William
Jeffrey D Angus
> So far the best longevity I've seen is from paper
I'm a big fan of paper. I have several QRS rolls of digital
music that are almost 100 years old and they still perform
faultlessly.