anyone format dvd to use like a usb flash drive?

No, that method of burning important data (packet writing) to rewritable CD/DVD media is not recommended, especially as blank "write once" media is now much cheaper than it used to be.

Packet writing is probably the least reliable method of burning files to disc as the data can easily become corrupted, which is what happened to me several years ago before Nero removed their "inCD" packet-writing feature.. I got wise & stopped using that method. Nero evidently didn't have much faith in it either after much negative feedback, which is why they dropped it.

For short-term storage it's okay (eg transferring a lot of data between two computers) and indeed it is quick & convenient, but that's all you should use it for.

I don't even buy rewritable media anymore, I only ever buy CD-R & DVD-R discs and burn data to them using commercial burning software (Nero).
 




thanks for response. i concur on the reliablity point. just found out the hard way that its unreliable enough to warrant ceasation on usage.

recently 1 cd read empty data and 1 dvd had a cyclic redundancy error in which 1 folder could not be read. good thing is the datas not that important but this still suck....

this technology so bad i don;t know why they even created it. going back to single burn as the data seem stable enough this way.





i got accustom to using cyberlink power2go burnware.

my current budget make it stingy to get two additional hd for storage. the cheapest i found was toshiba 1tb for $50 which is not that expensive and toshiba ranked well in a 2015 hd test i read. hopefully my budget get big enough in near future that 50 would feel cheap so 100 for 2 additional hd would not be expensive. till then....





 
The disc itself is also very important when it comes to optical media. There is a massive difference between say Japanese and Taiwanese made discs.

Although yes, rewritable discs can have a tendency to fail rather quickly. I remember reading that TY (Taiyo Yuden) is one of the best for DVD-R's, though I very briefly skimmed over it. My main interest was in Bluray blank media, where the situation was quite different.
 






have not looked into blu-ray, how they different? i just casually looked into that, they seemed more expensive for optical drive and disc.
 
Comparing capacity to capacity, Bluray discs can be cheaper, since each Bluray holds about 5 DVD's worth of data. The drives themselves are indeed more expensive.

HTL Bluray discs (the original older tech kind) uses inorganic material as the burn medium rather than organic that is used in CD and DVD's, which makes them naturally more resistant to environmental effects. For example, French ministry of culture did a study on reliability of optical media as an archive medium, they tested specifically Bluray discs. Some brands (Sony and Panasonic) withstood an obscene amount of punishment where as lower quality discs failed long before it. LTH (the organic dye BD-R discs) failed the fastest.

However, I will say that the reason I looked into BD-R's and not DVD's was because I wanted to do Archiving of TV show movie files (720p MKV's), and I would have easily needed to spend more money to physically store the DVD's than BD-R's (I could easily store one season of show on a single 25GB BD-R disc, whereas it would have taken me 5 DVD's). Lastly I also wanted to store irreplaceable data, and it more logical to me to use inorganic discs to remove a potential data corruptor.