Is DVD-RW backup reliable?

[bevills1]

Recently using Nero to burn DVD-RW data DVD to transfer files from 1 system to another I had trouble importing bookmarks and address book on the destination PC. After failure on several attempts, I tried again using USB 2.0 thumb drive and succeeded with no problem indicating files burned to data DVD must have been corrupt. Has anybody had similar problems, and is DVD-RW backup reliable?

[Krispy Kritter]

It should be reliable. It would depend on how the disc was burned. I typically burn RW discs the same as if I were using a regular disc. Single session and finalize the disc.

[jman98]

In theory, DVD-RW is reliable. Back when I got my first DVD burner I got one DVD-RW disc (a Sony - at the time it was the only brand I could find) and one DVD+RW disc (Verbatim I think) and I had a lot fewer problems with the DVD+RW, so I bought more DVD+RW discs. Some of it might be brands as Verbatim discs are a lot higher quality than Sony, but I just stuck with DVD+RW as they seemed to work reliably well.

[EddyH]

Might be many things...

Incompatibility of discs / type of disc with your machine, the other machine, or both.
Poor media brand or batch.
Damage suffered in transit, including scratches, shock, overexposure to sunlight, etc.
Poorly performing source/destination drive.
Too high a read or write speed.

Etc, etc.

If you have CD/DVDSpeed included in your Nero package, run it and do the disc quality / file reading checks on the disc at various speeds and see what the results are like. Also check with professionally made discs, CDRs, CDRWs, and as many other types of recordable DVD media as your machine takes (-R, +R, +RW, RAM..). Test the other PC with these same discs.

A single instance of read error does not a bad backup choice make, but it does warrant investigation.

In my own case, I've switched from using -Rs to +Rs and preferably +RWs on my own machine, as I've found that they give lower raw error rates (assuming that the figures are at all comparable like-for-like between + and - ...), not to mention reading better in both the PC drive (allegedly multistandard, with a preference for minus media?!) and the DVD player ('plus' exclusive)... particularly odd is the RWs being subjectively better than the Rs, even though they should be worse! Lower writing + reading speed, perhaps?

Also different brands can be a factor. Though they are slightly (but insignificantly) more expensive, I now get the own-brand discs from my local supermarket, as I've found them to be roughly on a par with certain big-name media company product, and they far outstrip certain white-label discs I've had off the web previously (some of which were basically between 50 and 0% usable, depending on the roll of the dice).

Finally do see what happens at different read and write speeds, it can be quite marked. Max speed will often give mine headaches, particularly at the end of a disc (I think the circuitry simply cannot handle the read data rate?), but taking it down a single notch (to the max 'write' speed) improves things greatly; conversely going below a certain other speed either no longer shows any improvement (just wastes time), or even gets worse! If your drive slows immediately / rapidly to a comparitively very low speed after encountering an error at very high speed, it might suffer a similar effect. You may yet be able to recover data from a misbehaving disc that has the only copy of some important file if you use e.g. Nero DriveSpeed to cap/force the drive to read at a (max of a) particular rate instead of "as fast as possible".

Good luck...
And sorry for being longwinded, but there's often really no quick solution or explanation to these things, they're complex

[bevills1]

The media was Office Depot DVD-RW 4x burned at 4x, and files were copied to other PC within minutes of burning as single session like Krispy Kritter typically does.

[pippas]

Never had a DVD-RW that didn't have errors six months down the line - never had any trouble with DVD-RAM though. I guess with the huge number of combinations of burners/media/ burning software, we are all likely to have different experiences.
That didn't ought to be the case of course.......

[TimA-C]

What do you do to your disks? I've still got DVD-RWs that have been used several times a week for the last 2 years+

[AlanHK]

I've got several DVDRWs I use for test burns mostly. After a few dozen uses they tend to get scratches, mostly towards the outer edge, still useful for projects less than 3 GB or so.

I tried a TDK "scratchproof", which cost about twice as much. Unfortunately, while it reads and verifies fine in my PC, on a DVD player it has two or three dropouts, making the video scramble for a minute each time -- at apparently the same position if I burn a different project. I've only tried the one disc, so this may just be bad luck.

[Skith]

it can depend as much on the reading drive as the writer. in combination with the media.

use good media, verbatim, or possibly fuji (hopefully ricoh). I have some maxell RWs I haven't used yet, but the above two have worked for me, I avoid generic / house brands at all cost

[ahhaa]

you guys are trotting out the usual suspects... read what bevills actually did again

transferring files by disc creates READ-ONLY clones- I'd say that's the only problem. Right-clicking the files for Properties & unselecting Read-Only should fix this. (hope so! )

[bevills1]

Doesn't transferring via thumb drive also create read only files, and why was there no problem with files transferred via thumb drive if thumb drive files are read only?

[Skith]

I'm not all to sure about the read only properties on +/-RW media, but I suspect ahhaa is correct. I am quite sure all files on an RW remain until the disc is formatted, even if you were to use something like packet writing software to delete a file, that file space can not be recovered from the disc until it is completely erased.

As for the thumb drive, the files should not be read only unless:
- They were originally read only when they were backed up and the backup program copied the Read-Only attribute.
- The Thumb drive has write protection enabled (this is a guess).
- Transferring via thumb drive (depending on how/what program you used for backup) may have reset the Read-Only attribute.

and is DVD-RW backup reliable?

That depends. For (very) short term backups and transfer of information it is fine, but it is not recommended for longterm archival storage. For longterm backups write once media +/-R media is recommended. The dyes used are much more stable than the crystalline phase change technology used in RW media which degrades relatively quickly. I'm not talking hours or days, but I wouldn't trust an RW with important data for months or years.

[bevills1]

Most likely ahhaa is correct about the cause of the problems if what Skith says about files copied to thumb drive not being read only unless write protection is enabled because write protection wasn't enabled in this instance. I only use RW media for short term storage such as transferring from 1 PC to another which is usually within a few days as Skith suggest. Additionally I no longer use packet writing for anything since I found it to be totally unreliable. For me packet writing worked sometimes, and other times media would appear blank making data written to it unrecoverable.

[noki]

short term...yes

long/archive...no

media subject to fail...usually after less than 10 rewrites (w_Verbatim which is pretty good quality)

[EddyH]

>> ahhaa

O_O ... Well spotted there! *ovation* ...

This would certainly be a likely suspect if transferring by -/+R, and probably with a single-sessioned -/+RW too... depends on how you're trying to import the file into the program. If you're trying to do anything that might conceivably attempt a write to the file on the DVD, then you're stuffed, and it explains why the memory stick worked better (no bevills, the thumbdrive acts just like a floppy/hard disc, full read-write priveleges; but unless you're using packet mode or DVD-RAM, you can't typically change files on +/- R/RW on the fly, it has to go thru a dedicated burn program, hence they're marked as read-only in the filesystem)...

I'm still voting for my pedantic geeky method At the very least, try copying the files to hard disc first and double-checking that their Read-Only attribute is turned off before importing, rather than doing it straight off the DVD. Then run it through any software disc quality checker you have available/can get hold of and see how it fares. And messing with the read speeds also - it's been something I've found useful for data recovery pretty much ever since getting my first 6x4x24x writer in 1999...

Oh and once you're done with the addressbook, blank the disc and write some other stuff on it, see if that copies OK too.

EDIT: Hm, seems I skipped the last two or three posts in the thread somehow

[bevills1]

Looking at some other files transferred via DVD-RW there is some file corruption because some bmp files also copied to DVD-RW don't open at all while some other bmp files open fine. I'm going to copy all files again by thumb drive instead of checking hundreds of files individually that were copied from the DVD-RW.