Thursday, August 22, 2019

Optical Media Durability: Update

A year ago I posted Optical Media Durability and discovered:
Surprisingly, I'm getting good data from CD-Rs more than 14 years old, and from DVD-Rs nearly 12 years old. Your mileage may vary.
It is time to repeat the mind-numbing process of feeding 45 disks through the reader and verifying their checksums. Below the fold, this year's results.

MonthMediaGoodBadVendor
01/04CD-R50GQ
05/04CD-R50Memorex
02/06CD-R50GQ
11/06DVD-R50GQ
12/06DVD-R10GQ
01/07DVD-R40GQ
04/07DVD-R30GQ
05/07DVD-R20GQ
07/11DVD-R40Verbatim
08/11DVD-R10Verbatim
05/12DVD+R20Verbatim
06/12DVD+R30Verbatim
04/13DVD+R20Optimum
05/13DVD+R30Optimum
The fields in the table are as follows:
  • Month: The date marked on the media in Sharpie, and verified via the on-disk metadata.
  • Media: The type of media.
  • Good: The number of media with this type and date for which all MD5 checksums were correctly verified.
  • Bad: The number of media with this type and date for which any file failed MD5 verification.
  • Vendor: the vendor name on the media
Surprisingly, with no special storage precautions, generic low-cost media, and consumer drives, I'm getting good data from CD-Rs more than 15 years old, and from DVD-Rs nearly 13 years old. Your mileage may vary.

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