DVD RAM?

[Pete]

Hi

I have read that DVD RAM is a much more reliable media for important
backups. However I cant seem to see any drives that take the media in
their cartridge, only DVD re-writers like the GSA 4167b that mention
DVD RAM but pressumably use the type 4 cartridge with the disk removed.

Can anyone recommend makes/models that use the disks in their caddies?

Thanks

 

[J. Clarke]

Hi

I have read that DVD RAM is a much more reliable media for important
backups. However I cant seem to see any drives that take the media in
their cartridge, only DVD re-writers like the GSA 4167b that mention
DVD RAM but pressumably use the type 4 cartridge with the disk removed.

Can anyone recommend makes/models that use the disks in their caddies?

You're looking for older SCSI drives. Ebay is your best bet, brands would
be Pioneer or Plasmon (not sure if Plasmon made drives or just relabelled
Pioneer).

The chemistry of DVD-RAM is the same as for DVD-RW, all that is different is
the formatting. There's no real reason to believe that DVD-RAM will be any
more durable than DVD-RW, its main advantage is convenience--DVD-RAM is
designed for data storage and can be treated like just another disk without
kluges such as packet-writing.

If you want durable random-access media in that capacity range you would do
better to go with magneto-optical.

 

[Arno Wagner]

Pete wrote:

You're looking for older SCSI drives. Ebay is your best bet, brands would
be Pioneer or Plasmon (not sure if Plasmon made drives or just relabelled
Pioneer).

The chemistry of DVD-RAM is the same as for DVD-RW, all that is different is
the formatting. There's no real reason to believe that DVD-RAM will be any
more durable than DVD-RW, its main advantage is convenience--DVD-RAM is
designed for data storage and can be treated like just another disk without
kluges such as packet-writing.

Actually there is a serious advantage: RVD-RAM uses verify on write
and does defect management. There is also a second serious advantage:
The cartridge.

If you want durable random-access media in that capacity range you would do
better to go with magneto-optical.

Agreed. DVD-RAM was intended to be the MOD succesor, but it is not
up to it. I have all my important stuff on 3.5" MODs. Usually two
copies. So far I have not los a single bit in 7 years using
this technology.

Arno

 

[J. Clarke]

Actually there is a serious advantage: RVD-RAM uses verify on write
and does defect management.

Verify on write doesn't mean that the data is going to be there a year down
the road when you need it. The big problem with DVD as an archival storage
medium is the stability of the chemistry, not the integrity of the writing
process.

There is also a second serious advantage:
The cartridge.

Which protects against scratches but does absolutely nothing to make the
chemistry more stable. Scratches are relatively easy to fix--there's a lot
of Lexan there to work with. The main real-world benefit of the cartridge
IMO is that it gives you a way to put an easily readable label on a
double-sided DVD-RAM. By the way, the cartridge does little to protect
against spills--first time I saw an optical disk demonstrated the salesman
to his dismay couldn't get the drive to read it. While he was off in
search of techs I idly examined the cartridge, opened the slider, and found
that it was full of several day old coffee.

Further, the cartridge is not required for something to be a DVD-RAM.

Agreed. DVD-RAM was intended to be the MOD succesor, but it is not
up to it. I have all my important stuff on 3.5" MODs. Usually two
copies. So far I have not los a single bit in 7 years using
this technology.

Would you have lost any of it without that technology?

 

[Arno Wagner]

Arno Wagner wrote:

Verify on write doesn't mean that the data is going to be there a year down
the road when you need it. The big problem with DVD as an archival storage
medium is the stability of the chemistry, not the integrity of the writing
process.

Actually verify on write deos help massively, as it identifies whether
a write was good or not. Doing it in software is not the same. If
the drive does it, it can use higher standards for successful verifies
than for standard reads. You are correct that it is not the only thing
that guarantees long-term readability. But chemical stability, once
assured, is not the main reliability problem of optical media. Dust,
areas gone bad, vibration, etc. is. For example I had one MOD that
had > 900 reallocated secotrs, because dust got into the cartridge.
Write only these would all have been potentially unreadable sectors,
possibly after some time (since the initial write could have been
borderline, but a slight degradation could have made them unreadable).
But the drive identified them on write and made sure that all data
was written well. And at the end that I was informed that tha last
write was not successful. I happen to know that this was dust, since
after cleaning and reformatting the same MOD has worked well and
reliably without significant additional defect sectors for several
yeras now. True, MOD is not quite the same chemistry as DVD-RAM,
but long-term stability is not really an issue with the chemical
structure if the disk was manufactured according to standard (a
real issue with El Cheapo DVD-RWs!).

There is A;sp a second thing: MOD/DVD-RAM are factory certified and
have an initial defect list, were the manufacturer found weak
spots with _very_ sensitive equipment. No such certification is
done for DVD-RW.

Which protects against scratches but does absolutely nothing to make the
chemistry more stable.

As I said the chemistry is not the issue with DVD-RAM.

Scratches are relatively easy to fix--there's a lot of Lexan there
to work with.

That may be a bit naive. Who has the time to polish their disks?
And what about dust, fingerprints, accidentd (drops, not correctly
aclingned in closing drive, ...)?

The main real-world benefit of the cartridge IMO is
that it gives you a way to put an easily readable label on a
double-sided DVD-RAM. By the way, the cartridge does little to
protect against spills--first time I saw an optical disk
demonstrated the salesman to his dismay couldn't get the drive to
read it. While he was off in search of techs I idly examined the
cartridge, opened the slider, and found that it was full of several
day old coffee.

Not an issue. Jous clean it off with soap and water. The data is still
there.

Further, the cartridge is not required for something to be a DVD-RAM.

Yes, and the stated reliability drops dramatically for the formats
without cartridge, or once a disk has been removed from cartridge.

Would you have lost any of it without that technology?

1.) Yes.
2.) Backups and archiveing would have been far more work and worry

Floppies: About half of my older 3.5" floppies were unreadable
when I backed them up 2-3 years after they were last used.
CD-R: First loss after 2 week on a disk that verified fine.
Numerous other losses or parial readabilities. And
a bitch to use.
CD-RW: Disk that verified fine in the writing drive, but was
unreadable in others. Also see CD-R.
HDDs: Two deathstars and two fried Fujitsus (the second my
mistake). The deathstars with warning signs to late to
get all data off.
Cheap tape (Quic-80): A nightmare. Compares that did not compare.
Tapes that were unreadable after a few weeks.

I have no experience with professional storage tape, but I
expect it comes on par with MOD for reliability, has not as
long data lifetime (say >10 years) and is far cheaper per byte
and far more expensive per installation.

Yes, I would have definitely lost data. Unless I had installed a
rigorous "3-copies and check each every year" regiment for my
backups. In contrast MOD is a "write and forget" technology, that
does not require any drivers or special softwware and will reliably
keep your data/family photos/stuff you care about safe for decades.
(Most vendors say > 50 years, a Phillips engineer told me probably

80 years, but there the acceleraded ageing models were getting

shaky...).

Interesting side note: In Japan MOD is all the rage. Seems people
there have more of a long-term outlook on storing data.

Second side note: In medical imagery, the law here requires the
images to be kept available for 20 years. It seems all the
scanners use MODs for this.

Arno

 

[J. Clarke]

Actually verify on write deos help massively, as it identifies whether
a write was good or not.

For certain values of "massive" perhaps.

Doing it in software is not the same. If
the drive does it, it can use higher standards for successful verifies
than for standard reads.

If the drive has the hardware to do this then what prevents the software
from using it?

You are correct that it is not the only thing
that guarantees long-term readability. But chemical stability, once
assured, is not the main reliability problem of optical media.

"Once assured" maybe, but who says that it's assured?

Dust,

There is a new technology developed for dealing with this, it is called a
"rag".

areas gone bad,

And why do they go bad? Because your "assured chemistry" is no such thing.

vibration, etc. is.

"Vibration"? Vibration removes data from optical media? I've never heard
that one before.

For example I had one MOD that
had > 900 reallocated secotrs, because dust got into the cartridge.

Well, now, that's one of the problems with cartridges.

Write only these would all have been potentially unreadable sectors,
possibly after some time (since the initial write could have been
borderline, but a slight degradation could have made them unreadable).

And what would cause such degradation?

But the drive identified them on write and made sure that all data
was written well. And at the end that I was informed that tha last
write was not successful.

Geez, Nero would have done that for 60 bucks.

I happen to know that this was dust, since
after cleaning and reformatting the same MOD has worked well and
reliably without significant additional defect sectors for several
yeras now. True, MOD is not quite the same chemistry as DVD-RAM,

MOD does not rely on a chemical change, it relies on a change in the
magnetic properties of a material with temperature. It's no more dependent
on chemistry than a tape or magnetic disk is.

but long-term stability is not really an issue with the chemical
structure if the disk was manufactured according to standard (a
real issue with El Cheapo DVD-RWs!).

To _what_ standard? Does the DVD-RAM standard mandate a given chemistry?

There is A;sp a second thing: MOD/DVD-RAM are factory certified and
have an initial defect list, were the manufacturer found weak
spots with _very_ sensitive equipment. No such certification is
done for DVD-RW.

Well, that's nice, but it still doesn't make the chemistry stable.

As I said the chemistry is not the issue with DVD-RAM.

Chemistry _is_ the issue. You can have absolutely perfect write and if the
chemistry decides to go to Hell a year down the road you lose the data.
This has been the major problem with DVDs for archival storage right along.
There are chemistries that are supposed to be reliable but no guarantees
that any given media use those chemistries.

That may be a bit naive. Who has the time to polish their disks?

One only polishes the disk if the disk is damaged. This is an infrequent
occurrence.

And what about dust,

Wipe, blow, or brush it off. Geez.

fingerprints,

If they cause a problem, you clean them off of course.

accidentd (drops,

What about them? Unless you roll your chair over it drops generally aren't
an issue.

not correctly
aclingned in closing drive, ...

If the drive closes at all you open it and reinsert the disk.

It amazes me that you trust the one thing that you can't inspect, the
chemistry, but worry about all this stuff that doesn't usually cause
problems in the real world and is generally easily correctable if it does.

Not an issue. Jous clean it off with soap and water. The data is still
there.

After you take the cartridge apart.

Yes, and the stated reliability drops dramatically for the formats
without cartridge, or once a disk has been removed from cartridge.

You trust "the stated reliability"? My respect for you has just dropped a
great deal. If it's mission critical data never trust anybody.

1.) Yes.
2.) Backups and archiveing would have been far more work and worry

Uh, copying it to MO _is_ "backups and archiving".

Floppies: About half of my older 3.5" floppies were unreadable
when I backed them up 2-3 years after they were last used.

There is something wrong with your hardware, Arno. You've been having all
of these problems, hard disks crashing right and left, diskettes unreadable
after 3 years, etc. You really need to get to the bottom of it instead of
just accepting that "that's the way it is".

CD-R: First loss after 2 week on a disk that verified fine.
Numerous other losses or parial readabilities. And
a bitch to use.

I don't see cranking up Nero or Roxio and dragging and dropping as being "a
bitch".

CD-RW: Disk that verified fine in the writing drive, but was
unreadable in others. Also see CD-R.

Only one, or multiples? If multiple you've got a rum drive. MO can suffer
the same problem.

HDDs: Two deathstars and two fried Fujitsus (the second my
mistake). The deathstars with warning signs to late to
get all data off.

So? If you have to "get the data off" then you aren't serious about your
data.

Cheap tape (Quic-80): A nightmare. Compares that did not compare.
Tapes that were unreadable after a few weeks.

Well, yeah, that's QIC. Totally worthless for any purpose. Tapes aren't
heavy enough to use for paperweights and aren't strong enough to prop up a
table leg and the drives are too light to work as a doorstop.

I have no experience with professional storage tape, but I
expect it comes on par with MOD for reliability, has not as
long data lifetime (say >10 years) and is far cheaper per byte
and far more expensive per installation.

DLT has at least a 30 year storage life. Not accelerated aging, on the
shelf. For equivalent capacity the cost is about the same as MO. The
thing is a 20 gig enterprise-grade DLT drive that cost $5K new is now
obsolete surplus that you get on ebay for 50 bucks in good working order.
The tapes cost about the same as MO cartridges.

Yes, I would have definitely lost data. Unless I had installed a
rigorous "3-copies and check each every year" regiment for my
backups. In contrast MOD is a "write and forget" technology, that
does not require any drivers or special softwware and will reliably
keep your data/family photos/stuff you care about safe for decades.

How would you like a nice bridge? I've recently come into the possession of
one. If that's not to your taste I also have a ski resort in Iowa and some
nice waterfront property in Louisiana. You find it trustworthy only
because it hasn't bitten you yet. Never, _ever_ trust one copy of
_anything_.

(Most vendors say > 50 years, a Phillips engineer told me probably
shaky...).

They claim that for DVD-R too. Why do you believe the one and not the
other? Accelerated aging models _are_ shaky until they've been correlated
with reality. Epson got bitten a while back with their archival
inks--seems that there was some common set of conditions that they didn't
allow for in their accelerated aging, and their prints were turning orange
in a matter of weeks for some users.

Interesting side note: In Japan MOD is all the rage. Seems people
there have more of a long-term outlook on storing data.

Or they're gadget junkies. The fact that something is the rage in Japan
doesn't make it useful. Remember tamaguchis? Or Aibos? Or totoros?

Second side note: In medical imagery, the law here requires the
images to be kept available for 20 years. It seems all the
scanners use MODs for this.

Which is fine, but kind of beside the point when you were defending DVD-RAM
earlier.

Personally the last time I lost data was about 20 years ago. Learned to use
RAID and tape and redundant servers and avoid a technological monoculture
and have little problem. Anything that I really care about is on at least
two servers, sometimes three, in separate locations and using different
operating systems. Lot of hassle you say? Nahh, it's all automated.

 

[Arno Wagner]

Arno Wagner wrote:

For certain values of "massive" perhaps.

If the drive has the hardware to do this then what prevents the software
from using it?

The software only gets a good/bad feedback. The drive itself sees
the raw signal before any ECC was used and sees the signal strength.
Therefore the drive can do much more than software.

"Once assured" maybe, but who says that it's assured?

Maybe you should read up on the technology you are talking about?

There is a new technology developed for dealing with this, it is called a
"rag".

So, do you clean your disks down to microscopic levels before each
write? Sounds highly impractical to me.

And why do they go bad? Because your "assured chemistry" is no such thing.

No. Because there are manufacturing variations, dust, imputities.
Ever asked yourself whu HDDs have defect secors?

"Vibration"? Vibration removes data from optical media? I've never heard
that one before.

Vibration can cause marginal writes.

Well, now, that's one of the problems with cartridges.

I don't think that deserves an answer.

And what would cause such degradation?
Time?

Geez, Nero would have done that for 60 bucks.

No, it could not. See above.

MOD does not rely on a chemical change, it relies on a change in the
magnetic properties of a material with temperature. It's no more dependent
on chemistry than a tape or magnetic disk is.

Wrong. It relies of a magnetically induced chemical change. And
BTW MOD, DVD-RAM, DVD-RW are all variations of phase change. The
"chemical" you are probably thinking about is the dyes in the
media that can not be rewritten.

To _what_ standard? Does the DVD-RAM standard mandate a given chemistry?

It mandates a specific material, yes. And DVD-RAM is not dye based.

Well, that's nice, but it still doesn't make the chemistry stable.

Chemistry _is_ the issue. You can have absolutely perfect write and if the
chemistry decides to go to Hell a year down the road you lose the data.
This has been the major problem with DVDs for archival storage right along.
There are chemistries that are supposed to be reliable but no guarantees
that any given media use those chemistries.

One only polishes the disk if the disk is damaged. This is an infrequent
occurrence.

Actyally you need to polish before each write, since scratched degrade
the write signal.

Wipe, blow, or brush it off. Geez.

See above.

If they cause a problem, you clean them off of course.

See above.

What about them? Unless you roll your chair over it drops generally aren't
an issue.

They are.

If the drive closes at all you open it and reinsert the disk.

It amazes me that you trust the one thing that you can't inspect, the
chemistry, but worry about all this stuff that doesn't usually cause
problems in the real world and is generally easily correctable if it does.

After you take the cartridge apart.

Yes, so what?

You trust "the stated reliability"? My respect for you has just dropped a
great deal. If it's mission critical data never trust anybody.

I trust that the stated reliability is an upper bound.

Uh, copying it to MO _is_ "backups and archiving".

There is something wrong with your hardware, Arno. You've been having all
of these problems, hard disks crashing right and left, diskettes unreadable
after 3 years, etc. You really need to get to the bottom of it instead of
just accepting that "that's the way it is".

I don't see cranking up Nero or Roxio and dragging and dropping as being "a
bitch".

Only one, or multiples? If multiple you've got a rum drive. MO can suffer
the same problem.

3 our of 3 MO drives with zero problems. All in use for years now.
I had the above several times with several different writers.

So? If you have to "get the data off" then you aren't serious about your
data.

That is the point. I did not, because I had backup on my MIODs.

Well, yeah, that's QIC. Totally worthless for any purpose. Tapes aren't
heavy enough to use for paperweights and aren't strong enough to prop up a
table leg and the drives are too light to work as a doorstop.

DLT has at least a 30 year storage life. Not accelerated aging, on the
shelf. For equivalent capacity the cost is about the same as MO. The
thing is a 20 gig enterprise-grade DLT drive that cost $5K new is now
obsolete surplus that you get on ebay for 50 bucks in good working order.
The tapes cost about the same as MO cartridges.

You can go that way, no argument here.

How would you like a nice bridge? I've recently come into the possession of
one. If that's not to your taste I also have a ski resort in Iowa and some
nice waterfront property in Louisiana. You find it trustworthy only
because it hasn't bitten you yet. Never, _ever_ trust one copy of
_anything_.

With enough redundancy, I do. For critical stuff, I of course have two
or more copies in different physical locations. After all if the
house burns donw, MODs will not survive either.

They claim that for DVD-R too. Why do you believe the one and not the
other? Accelerated aging models _are_ shaky until they've been correlated
with reality. Epson got bitten a while back with their archival
inks--seems that there was some common set of conditions that they didn't
allow for in their accelerated aging, and their prints were turning orange
in a matter of weeks for some users.

I trust MOD, because it is a mature technology. And because it is
not mass-market, but professional level. Same reason why claims
for SCSI drives are usually more true than those for IDE drives.
Different culture.

Or they're gadget junkies. The fact that something is the rage in Japan
doesn't make it useful. Remember tamaguchis? Or Aibos? Or totoros?

And they are all gone. MOD is not.

Which is fine, but kind of beside the point when you were defending DVD-RAM
earlier.

Personally the last time I lost data was about 20 years ago. Learned to use
RAID and tape and redundant servers and avoid a technological monoculture
and have little problem. Anything that I really care about is on at least
two servers, sometimes three, in separate locations and using different
operating systems. Lot of hassle you say? Nahh, it's all automated.

I have no issue with that. However not everybody has that possibility.

Arno

P.S.: You should really look up the difference between dye based
media and phase-change media. You should also realise that all
the dust/vibration/whatever issues with optical media are while
writing to them and that is were the verify by the drive makes
all the difference.

 

[J. Clarke]

The software only gets a good/bad feedback. The drive itself sees
the raw signal before any ECC was used and sees the signal strength.
Therefore the drive can do much more than software.



Maybe you should read up on the technology you are talking about?

I have. The chemistry of DVD-RAM and of DVD-RW is the same. Both are
phase-change media. All chemical concerns that apply to one apply to the
other. There are many chemistries used in RW media, and nothing that I
have ever seen requires that any specific chemistry be used in DVD-RAM.

So, do you clean your disks down to microscopic levels before each
write? Sounds highly impractical to me.

What leads you to believe that disks need to be "cleaned down to microscopic
levels before each write"?

No. Because there are manufacturing variations,

Which would make the disk "go bad" why?

dust,

Which would make the disk "go bad" why?

imputities.

Ah, there's that so-called "assured chemistry" again.

Ever asked yourself whu HDDs have defect secors?

The defect list is recording defects that were present at manufacture.
Additional defects that occur in service are generally physical in nature.

Vibration can cause marginal writes.

That your wonderful read-after-write technology didn't detect? Do tell.
Maybe it's not so good after all.

I don't think that deserves an answer.

Suit yourself.

Time?

If the chemistry is "assured" for a hundred years then why would "time" make
a difference in any disk that you have ever owned?

No, it could not. See above.

I saw above. If you are relying on that to ensure that the media is good
for archival storage then you really, really don't understand the problem.

Wrong. It relies of a magnetically induced chemical change.

If MO relies on "magnetically induced chemical change" then so do hard
disks. I don't consider magnetization or demagnetization of a domain to be
"chemical change".

And
BTW MOD, DVD-RAM, DVD-RW are all variations of phase change.

No, MOD is not phase-change. MOD is ferromagnetic. DVD-RAM is phase
change.

The
"chemical" you are probably thinking about is the dyes in the
media that can not be rewritten.

The rewriteable media are also phase change. I don't know where you get the
idea that they are not.

It mandates a specific material, yes. And DVD-RAM is not dye based.

It isn't? You really do need to tell that to the manufacturers of DVD-RAM
media as they are laboring under the misconception that it is.

Actyally you need to polish before each write, since scratched degrade
the write signal.

Only if it is scratched. If you handle it with even the slightest degree of
care it won't be.

See above.



See above.



They are.

I've never experienced a write failure due to all these causes of damage
that you fear. But I do look at the disk before I put it in the drive.

Yes, so what?

Another step in the process, for a very minor degree of protection.

I trust that the stated reliability is an upper bound.

So you plan on living a hundred years so that you can replace the media
then? If not then what exactly do you find to be the utility of the
information?

3 our of 3 MO drives with zero problems. All in use for years now.
I had the above several times with several different writers.

So? I've had DVD and CD drives in use for years now with zero problems.

That is the point. I did not, because I had backup on my MIODs.

You're missing the point. If you're serious about your data then a disk
failure just means "swap the drive and put up with slow performance for a
couple of hours while the array rebuilds".

You can go that way, no argument here.



With enough redundancy, I do.

If you have redundancy means that you have more than one copy. That's the
definition when used in relation to data storage.

For critical stuff, I of course have two
or more copies in different physical locations. After all if the
house burns donw, MODs will not survive either.



I trust MOD, because it is a mature technology. And because it is
not mass-market, but professional level. Same reason why claims
for SCSI drives are usually more true than those for IDE drives.
Different culture.

Oh, geez, not _this_ again. The last drive I had to replace was a SCSI
drive in an array. Ended up replacing the whole array with a couple of IDE
drives, because the oh, so wonderful professional grade SCSI drive that I
got to replace the failed drive, despite being the same brand, and same
model, had a significantly lower capacity and couldn't join the array, and
replacing the whole array would cost far more than it was worth.

And they are all gone. MOD is not.

Yet.

It always amuses me when someone says "this is good because the Japanese do
it". I remember some twit telling me that about "cold fusion". Told me
that it was a real technology because "those flinty eyed Japanese engineers
at Toyota" were going to have a cold-fusion powered car on the road by
2001.

The Japanese can do stupid things just like everybody else. I suspect that
if you investigate you'll find that it just has had a good sales pitch over
there.

I have no issue with that. However not everybody has that possibility.

Of course they do. If they don't implement it it is their choice. You can
get a pretty good server for less than the price of a new MO drive. Just
have to think "used equipment".

P.S.: You should really look up the difference between dye based
media and phase-change media.

I've looked it up, I find absolutely nothing there that indicates that there
is any difference in the chemistry between DVD-RAM media and DVD-RW media.
And I have never heard of _anybody_ recommending DVD-RW for archival
storage.

You should also realise that all
the dust/vibration/whatever issues with optical media are while
writing to them and that is were the verify by the drive makes
all the difference.

If it was the kind of huge problem you make it out to be perhaps.

 

[Splork]

Actually there is a serious advantage: RVD-RAM uses verify on write
and does defect management. There is also a second serious advantage:
The cartridge.


Agreed. DVD-RAM was intended to be the MOD succesor, but it is not
up to it. I have all my important stuff on 3.5" MODs. Usually two
copies. So far I have not los a single bit in 7 years using
this technology.

Arno

Hi,

Pardon my interest.

I use MO as well. 3.5" and 5.25" Truly archival. Still deal a bit in drives
and media as well though mostly 3.5". The 5.25 inch drives that are predominant
are Sony, Maxoptix, Pinnacle and a few others. Pioneer had Phase change (PD)
media if I recall and were incompatible with MO. Plasmon had MO drives but I
have only had my hands on the Plasmon media and it was MO.

3.5" drives were made by fujitsu and Olympus. I think every other vendor OEMd
these 2 Mfgs.

My Question:
Do you have any experience of what actual write times for DVD-RAM are?? I know
it is slower due to the implementation of a more reliable format. Interested
in the comparison. The main drawback in MO is the slow write times.

I agree that the built in verify function in MO and now DVD-RAM is a major
benefit.

Thanks

BTW There were 3.5" and 5.25" cleaning kits to decontaminate the cartridges.
Since 5.25" cartridges used both sides of the media they were more easily
impacted than their smaller bretheren which used the underside to R/W. After
dusting em off, an optical fluid was used to clean (de-haze) them. Really
filthy cartridges (from badly placed jukeboxes usually) had the inner shell
soiled as well and were not rehabilitable unless disassembled and washed.

 

[Arno Wagner]

Actually there is a serious advantage: RVD-RAM uses verify on write
and does defect management. There is also a second serious advantage:
The cartridge.


Agreed. DVD-RAM was intended to be the MOD succesor, but it is not
up to it. I have all my important stuff on 3.5" MODs. Usually two
copies. So far I have not los a single bit in 7 years using
this technology.

Arno Hi,

Pardon my interest.[/QUOTE]

I use MO as well. 3.5" and 5.25" Truly archival. Still deal a bit
in drives and media as well though mostly 3.5". The 5.25 inch
drives that are predominant are Sony, Maxoptix, Pinnacle and a few
others. Pioneer had Phase change (PD) media if I recall and were
incompatible with MO. Plasmon had MO drives but I have only had my
hands on the Plasmon media and it was MO.

3.5" drives were made by fujitsu and Olympus. I think every other
vendor OEMd these 2 Mfgs.

Just a remark: Fujitsu still makes them and likely will for quite
some time. It is a small market, but I expect profitable, since
the people using MO will/can usually settle for nothing less.

[...]

BTW There were 3.5" and 5.25" cleaning kits to decontaminate the
cartridges.

And again, there still are. I have the 3.5" kit from Fujitsu.
Without it cleaning the disks is a bitch. With it, it is
pretty simple and definitely something any halfway competent
person can do.

Arno