Reliability for data recording and backup


(I had posted this in the Newbie forum, since I’m a newbie :), but I’ve been suggested to post it here)

I’ve been trying to find details on data recording reliability on DVD REWRITABLE media, but can’t find any good source either on the internet or these forums. All those KProbe graphs showing errors everywhere make me freak out, and that’s why I’m asking.

I can see writing +RW discs formatted as UDF makes the “big floppy disk” idea workable (I’m doing it right now) but I have no idea of how reliable this is.

DVD-RAM is usually referred as the best data-oriented media, but its support is not very widespread and I can’t seem to find any information about its future.

Can I really trust DVD media to backup my personal data?

What are the differences between different formats for this task? (Is +RW any better than -RW?)

Is DVD-RAM really the only reliable solution?

Thanks for any help


I can’t give many technical details (I am no engineer), but from what I understand, I can say that if you wish to archive, you should not use +/- RW media. Rewritable media is less chemically stable (I think thats the right way to say it) than write once media (+/- R). RWs use phase-change technology (for CD-R’s the recording layer is a crystaline like chemical that changes “shape” when exposed to a laser, I think i read DVD RWs are similar). This crystaline substance breaks down over time (much faster than the dyes used in write-once media.)

I cannot say if DVD-RAM also suffers from this flaw. The advantage for the -RAM format is it was designed for “random access” like use. That being, like a floppy or hard drive. It also allows for many more “re-writes” than RW media.

At least, that is my understanding of RW/RAM. Feel free to correct me if any of the above is incorrect.

DVD-RAM is DEFINITELY the more superior and robust rewriteable DVD format.
If you need reliable rewriteable DVD media, get a DVD-RAM recorder ( LG ).

Between DVD+RW and DVD-RW, I have definitely had less problems with DVD+RW.
However, this might be due to +RW being a more ‘evolved’ format and that it has obtained higher speeds and higher production quantities compared to -RW.

Thanks for the answers. Can you point to some resources on the internet where I can find more technical details about all this?

I’m already using write-once media for archiving. The question is using rewritable media for backup and “big floppy” use of DVD (ie. moving data from one computer to another; keeping a “drivers DVD”, an “apps DVD”, a “hotfixes DVD” etc. up to date and that sort of use).

I’m not sure about going the DVD-RAM route for two reasons:

1- I’m not only saving data for myself, but also for exchage them with others and I’ve read everywhere DVD-RAM can’t be read by too many drives out there. Is that true?

2- Given the scarce support for DVD-RAM, it looks as a dying technology and I’m a bit scared to invest in it. I can’t find any reasonable forecasts about the future of DVD-RAM.

That’s why I was wondering, is +RW good “enough” for short-term data-recording and daily backups?

Thanks again!

A few DVD-RAM articles found by doing a quick google search:

  1. Yes, it is true that even reading support for DVD-RAM is scarce and only available in a small percentage of drives.

  2. DVD-RAM isn’t going to “die” as far as I can see. Many businesses use DVD-RAM backup as an alternative to tape backup for data archival, including my own place of business :slight_smile: . I’ve also heard rumors that the DVD-RAM “camp” would like to get to 16X speeds some day if possible.

DVD+RW seems to be quite fine for short term storage and the purpose(s) that you have listed. Just make sure to use good media such as RICOHJPNW11 or MKMA02.

Thanks, I guess I’ll have to decide between an LG drive and the NEC3500 which seems to be the choice at every comparison I’ve come to read so far.

I’ll search for the availability of DVD-RAM media in Europe.

Thanks for all the advice.