Have gone from on site and off site back ups of CDs and DVDs. Just purchased a Blu-Ray burner. The disks that say "Write once"...can I multiple session and write once on Monday, then add files on another day? I have no need to use "rewritable" meaning I do not want to archive, then delete or over write files similar to a hard drive. The teminology has me confused. Thanks in advance.
Dave

Interesting question! My understanding is that DVDs never had relaible multi-session burn. Whenever attempting multisession, I always got a warning message to the effect that additional burning might exclude access to previous sessions on other DVD drives.

This proved to be the case in practice. The multisession option proved to be only effective on the same burner. On a different burner, the previous session would be inaccessible after further recording.

Whether or not this scenario applies to Blu-ray, I don't know.

I am sorry i dont know the answer to your question, but my question is why are you bothering to use blu-ray for back up. A portable USB hard drive is far cheaper / reliable / convenient to use. The GB/$ is far cheaper also.

You make a good point. At one time CDs, then DVDs were very expensive, but now are very reasonable; hopefully, Blu-Ray disks will come down in cost as time goes on and more people use them. I have a 750 GIG USB external backup. I back up new files daily, but then archive to 2 separate DVDs, CDs, or Blu-Ray disks, and keep one on site, one off site. BTW the Maktor external drive failed 1st week and was replaced by the manufacturer.
Dave
www.modernpictorials.com

I've only burnt one bluray to date, since I purchased my laptop with a burner built in.
Aside from being a laptop, the speed of bluray isn't at a stage where I find it competitive. It may add an extra layer of redundancy to your data, but personally, the time spent burning a bluray, is better spent uploading it to a portable hard drive unit.

I can't say I've written more then once on a single disk, but from personal experience, like the others, it's been problematic doing so on DVD's from day one... and continues to this day.
The benifits of DVD's is that they're pretty cheap now per disk, and if you don't fill one up, it's no great loss.