Data lost on CD-RW...- help appreciated

Data lost on CD-RW...- help appreciated

Post by Mike Richte » Mon, 21 Sep 1998 04:00:00



Please begin your post - and put into your subject - that your problem
is with UDF. We have to dig down into the body and draw that conclusion
from incidental comments.

It makes a very big difference in trying to solve the problem.


> Transferring a large number of photos from PC to CD-RW (Using HP7100external
> and Adaptec Easy CD 2.0).

> Transfer halted on one file with error saying unable to read target
> directory.

> Then, clicking the eject option  gave a message that some files were still
> open, even though I'd closed Explorer and all other applications.

Yup. Your writeback cache had not been emptied, so files were open and
data were being written ...

Quote:> it then offered me the option of ejecting the CD by overriding the open
> files, but once that was done, the CD-RW was no longer readable.

until you commanded it to stop. At which point, you had created garbage
on the disc.

Quote:

> Tried all I could, but nothing would recognise the CD-RW again.  when
> opening up through Easy CD, it stated that it was a blank CD-RW but could be
> formatted for use with Easy CD.

> Worse still, in case of this sort of thing, I have 2 CD-RW disks; one HP and
> one RICOH.
> The same thing happened on both discs, meaning I lost the entire contents of
> both discs.
> Fortunately, there was nothing irreplaceable on the them, but clearly there
> could have been;
> Anyone know why this happened, and how to
> A, Prevent from reoccurring, and B,

Move fewer than 50 MB or so at a time to a UDF disc. There are
filesystem problems which occur when you try to handle more than 100 MB
at a time; the reason seems to be buried in interactions of file
accesses, but this unfortunate workaround is the best that we've found
so far.

Quote:> Read a CD-RW disc that's had it's index screwed up...?

Not possible - yet. Maybe someday, but an invalid filesystem can't be
patched up easily.

Mike


http://mrichter.simplenet.com
CD-R http://resource.simplenet.com

 
 
 

Data lost on CD-RW...- help appreciated

Post by Ian » Tue, 22 Sep 1998 04:00:00


Transferring a large number of photos from PC to CD-RW (Using HP7100external
and Adaptec Easy CD 2.0).

Transfer halted on one file with error saying unable to read target
directory.

Then, clicking the eject option  gave a message that some files were still
open, even though I'd closed Explorer and all other applications.
it then offered me the option of ejecting the CD by overriding the open
files, but once that was done, the CD-RW was no longer readable.

Tried all I could, but nothing would recognise the CD-RW again.  when
opening up through Easy CD, it stated that it was a blank CD-RW but could be
formatted for use with Easy CD.

Worse still, in case of this sort of thing, I have 2 CD-RW disks; one HP and
one RICOH.
The same thing happened on both discs, meaning I lost the entire contents of
both discs.
Fortunately, there was nothing irreplaceable on the them, but clearly there
could have been;
Anyone know why this happened, and how to
A, Prevent from reoccurring, and B,  Read a CD-RW disc that's had it's index
screwed up...?

Cheers for your help,

 
 
 

Data lost on CD-RW...- help appreciated

Post by Mike Richte » Tue, 22 Sep 1998 04:00:00



> Apologies for that Mike; but I didn't (&still don't) know what UDF is.  I
> tried to give all appropriate information.

> I was transferring a total of about 80 Mb of files, but doing it at about 20
> Mb at a time.
> Do you mean I should eject the CD-RW disc every 50 Mb of data or so to allow
> it to update the file system?

No - what you were doing should have been fine. Copy 20 MB, let things
quite down (and caches empty, etc.), then move more.

I have had no problems moving moderate quantities of data at a crack,
but have failed when trying to write a 150-MB file.

Quote:> >Yup. Your writeback cache had not been emptied, so files were open and
> >data were being written ...

> Mike: Is this something I should be doing manually myself? (How?);

Frankly, I've never figured out a way to tell when the cache was
emptied. Well, one way is to try to eject the disc. If the cache is
clear, it will; if not, it should give you the option of forcing eject
(DON'T DO IT!) or letting it finish.

A very undesirable situation! I think I'll use my exalted position on
the beta team to suggest something for the future. How about having the
icon active (as when ECDC is writing)?

Mike

--

http://mrichter.simplenet.com
CD-R http://resource.simplenet.com

 
 
 

Data lost on CD-RW...- help appreciated

Post by Mike Richte » Tue, 22 Sep 1998 04:00:00


Unfortunately, UDF is very complicated. The hardware folks say: use your
CD-R just as you would a floppy - which is great until it fails (which
it will) and you discover that it's much more complex than a floppy or a
hard drive.


> One last thing though;  In my original post, I mentioned straight away that
> it was a CD-RW disk using Adaptec.  Am I right from your notes that this
> could Only mean I was using UDF anyway...?  Further more, I'm still not too
> clear on the significance of it...

No, you can use ordinary authoring s/w (such as ECDC, CDRWin) on an
erasable blank. All that is significant here is that when you are
writing UDF, an erasable is formatted in fixed-length packets; a
write-once is formatted in variable-length.

Mike


http://mrichter.simplenet.com
CD-R http://resource.simplenet.com

 
 
 

Data lost on CD-RW...- help appreciated

Post by Ian » Wed, 23 Sep 1998 04:00:00


Apologies for that Mike; but I didn't (&still don't) know what UDF is.  I
tried to give all appropriate information.

I was transferring a total of about 80 Mb of files, but doing it at about 20
Mb at a time.
Do you mean I should eject the CD-RW disc every 50 Mb of data or so to allow
it to update the file system?

Very much appreciate your help here Mike...

Also:


>Please begin your post - and put into your subject - that your problem
>is with UDF. We have to dig down into the body and draw that conclusion
>from incidental comments.
>> Transfer halted on one file with error saying unable to read target
>> directory.

>> Then, clicking the eject option  gave a message that some files were
still
>> open, even though I'd closed Explorer and all other applications.

>Yup. Your writeback cache had not been emptied, so files were open and
>data were being written ...

Mike: Is this something I should be doing manually myself? (How?);
 
 
 

Data lost on CD-RW...- help appreciated

Post by Ian » Wed, 23 Sep 1998 04:00:00


Mike,
I've printed off your exceptionally detailed and well presented  .pdf
Primer from your web page.  Thank you for taking the time to prepare such a
document; and please disregard my other message asking what UDF is as I'm
now reading up on it.  However, keep in mind that many people wouldn't have
a clue about such things.  I still have no idea of the file structure on a
standard floppy and have been using them for years...

I'll read through your document, and hopefully learn an awful lot.  In the
mean time, I'll keep my transfers under 50 MB too.

One last thing though;  In my original post, I mentioned straight away that
it was a CD-RW disk using Adaptec.  Am I right from your notes that this
could Only mean I was using UDF anyway...?  Further more, I'm still not too
clear on the significance of it...
However, as stated, I'll do my reading;  thanks again for your web page
help...

Cheers,

Ian


>Apologies for that Mike; but I didn't (&still don't) know what UDF is.  I
>tried to give all appropriate information.

>I was transferring a total of about 80 Mb of files, but doing it at about
20
>Mb at a time.
>Do you mean I should eject the CD-RW disc every 50 Mb of data or so to
allow
>it to update the file system?

>Very much appreciate your help here Mike...

>Also:


>>Please begin your post - and put into your subject - that your problem
>>is with UDF. We have to dig down into the body and draw that conclusion
>>from incidental comments.

>>> Transfer halted on one file with error saying unable to read target
>>> directory.  Then, clicking the eject option  gave a message that some

files were still open, even though I'd closed Explorer and all other
applications.

- Show quoted text -

Quote:

>>Yup. Your writeback cache had not been emptied, so files were open and
>>data were being written ...

>Mike: Is this something I should be doing manually myself? (How?);

 
 
 

1. Help w lost data (Ricoh CD-RW)

Help!

I've lost 95% of data backed up to a Ricoh CD-R disk, using a
Ricoh MP 6200S (CDRW) drive.

Tech support from Ricoh does not answer their online form submissions
(3 weeks since), nor their email (7 days since), nor their phone (3
days since).

I wrote 512 MB, on a single track,  in multisession mode, 2 sessions,
as follows:
1st session, I wrote about 460 MB and left the session open.
2nd session, I wrote about  40 MB to the same track and closed the
disk.

The track list shows (use monospaced font here):

Sess Trck Mode                             Adrs      Length
  01   01    CDROMXA Mode 2 ms 000000 262225   512.1MB
  02   02    CDROMXA Mode 2 ms 273625 000302         .5MB

Track 1 has vol ID "971102_2032 ".
Track 2 has vol ID "971102_2338".
The latter ID (...2338) is displayed in Windows Explorer, but adds up
to 16 MB of data.

This does not correspond to either of the tracks shown on the disk,
nor to either of my recording sessions.

I can copy each track to an ISO image file, using Easy-CD Pro. Is
there a way to access the directories and files in an ISO file
directly, without creating a CD?

Does  anyone  have any idea what might have happened?

Thanks for any help.

Abair

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