RW isn't a stable medium?

Someone said “RW isn’t a stable medium”. Why is that? Please, someone explain. Thank you.

To my personal experience it is not. But I will leave the explanation to those who are experts in this field.

BUMP… anyone else?

“packet writing” is not stable software period. I tired it for a while with different brands of burning software but ultimately anyone relying on CDRW for back up alone is going to lose data. sooner or later it’s going to fail and your disc will be unreadable.

I ditched packet writing over a year ago and I dont miss it a bit. I back up data to CDR’s DVD+R and TWO external hard drives. backing up to a hard drive is much faster anyway.

Burning DVD+/-RWs doesn’t necessarily mean that you have to use packet writing software. You can burn them like “regular” DVD+/-R discs also.

Good quality DVD+/-RW media is “stable”, and can reliably be overwritten a thousand times (if you treat the discs correctly, like explained here), but there are other formats like DVD-RAM available that are even more robust (for several reasons; do a forum search). But just because DVD-RAM is more robust, it doesn’t mean that DVD+/-RW is unstable. I think you might have misunderstood this MaverickMitchell.

i use in-cd to write on DVD-WRs dynamically. is this unsafe? is it better to erase the disc and start over?

The most common symptom I experience is that after using it a while, the I/O operations hang (usually at the worst possible moment ;)) and then I’ve lost the data on the disc. If I’m lucky, I’m able to erase/reformat the whole disc and start over, but I have encountered situations where I couldn’t even force a full erase and so I can’t use the disc anymore.

I did manage to find at least one way to use it pretty reliably, though:

I have observed that the problem gets worse with more complex directory structures and with the number of files. Therefore, if you’re using RW’s as a backup medium, I would recommend combining all your backup data into one large file (i.e. with PKZIP, etc). If you’re comfortable with command-lines and scripting (i.e. BAT files), you can automate your whole backup operation with a single icon click. For example, my script file ZIPs all the directories I want to back up, deletes the old ZIP file on the RW, copies the new ZIP file from the hard disk, and does a compare. I’ve been doing my backups almost every day this way with no problems so far. With an ultra-speed CD-RW I can back up hundreds of megs (depending on the compression ratio) in less than 10 minutes. I also alternate between two discs to help keep Murphy’s Law at bay (i.e. by coincidence the disc write screws up and your hard disk crashes at the same time).

This is all with a CD-RW, though. I don’t have experience in trying this with DVD +/- RWs yet.

  1. RW (both CD and DVD discs) are rated for 1,000 rewrite cycles and generally known to be far less reliable than quality write-once media or something like dvd-ram (1,000 writes verus 100,000 for dvd-ram). Chemically they are very different. On top of that the way the data is written on something like dvd-ram and verified (or not…) is another distinguishing factor that might make you think twice before saving important data solely on RW (or R). DVD-RAM is far more robust.

  2. Packet-writing (to give you the convenience of drag n drop hard drive-like recording/erasing on CDRW and DVDRW) is still inherently unreliable (or perfectly fine, depending on who you talk to).

Those are 2 reasons that go some way to explaining why the current popular RW formats are probably not to be solely relied on for mucho important back-ups. (but then again, solely relying on any one format or disc is probably bad practice to start with, eh).