how good is the data reliability with CD ROM and DVD RAM?

I had a home CDR back when they were over $1000+ new. The media turned out to be very reliable (and I have a bunch with gold, blue, green dye) and it still readable as long as you didn't scratch the optical reflective layer. I also used a laser printed paper cover which probably kept air out. I think the media had better quality control when a single CDR was $8 a pop then with a spool that costs $20. DVD recordable media was error prone if you used DL disks. I only used CDRW media for short term moving of files so I don't know how well they do long term. I have a BDXL Blueray drive I barely use since anything I need to get at is either online on my server of offline on a tape of some kind (LTO mostly but some DAT and AIT as well). I have old IBM MO Worm disks that are still readable, same with all my MO disks (3.5" 130MB, 5.25" 1.3GB) but drives can be iffy. I would bet that MO media will outlast us all while finding a drive to read them will be a problem. -----Original Message----- From: Carlo Pisani via cctalk Sent: Saturday, July 21, 2018 11:14 AM To: General Discussion: On-Topic and Off-Topic Posts Subject: how good is the data reliability with CD ROM and DVD RAM? hi yesterday I was shocked by a couple of videos on Youtube where guys pointed out their negative experiences with CD ROM and DVD RAM as media for their own backup. They complained their data completely lost after 5 years of storage in CD ROMs, pointing out that their CDs were perfectly conserved and kept clean without scratches, but all the data is gone lost since the media is unreadable. This is what they said in the video. I have a lot of backup here stored in CDs, and I have recently bought an SCSI DVDRAM unit to create new backups in caddies DVD-RAMs (of 4.2Gbyte each) what is your experience? --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus