They’re a very common form of personal backup. A few discs and an USB writer and you get a very long lasting medium for passwords, personal files, family photos etc.
Can also archive multimedia of course, the smallest discs are 25 GB and can pack a few films, a season of a series, or a lot of music.
finley@lemm.ee 2 months ago
i guess, but they’re not great for backup. Eps. R/RW optical media doesn’t last that long (5-10 years) and is easily damaged. You’d be better off with tape for long-term storage. or an M-Disk or some similar magnetic backup solution.
lemmyvore@feddit.nl 2 months ago
I beg to differ. I’ve been backing things up to optical for 25 years now with minimal issues. CDs could be easily scratched but it hasn’t been the case for DVD and BR.
M-DISK uses in-organic substances that make the discs mostly immune to exposure but it’s a more recent invention. Proper storage and handling still goes a long way towards protecting discs even if they’re not in-organic.
Majestic@lemmy.ml 2 months ago
M-Discs had merit in the DVD era. It’s a common refrain of those who don’t know better to claim they mean anything in the Blu-ray era. They don’t.
Standard Blu-ray Discs have all the technologies that supposedly make m-discs so long lasting and as far as media that isn’t continuously updated and hashed from live storage medium to live storage medium (cold, archival storage unpowered) they are about as good as you’ll get.
They are much tougher than DVDs. Of course a variety of things go into how long a disc remains readable and without damage to data including luck with regards to no impurities in the batch. Even m-disc themselves based their longest claims off storage in ideal situations like an inactive salt mine (commonly used for archives by governments). Kept out of sun, away from extreme heat (including baking in uninsulated 120 degree F heat all summer year after year), away from high humidity and away from UV exposure to the data side of the disc as well as scratches and such and they should last a quarter to half a century, some more.
TGTX@lemmy.world 2 months ago
Politely disagree. M-disc for BD-Rs are still absolutely worth the money if you want to properly archive something. You have to be careful with normal BD-Rs because there are two different types of recording material: High to Low and Low to High (LTH). You want to stay away from BD-R LTH discs as their longevity isn’t as good as the High to Low discs.
Majestic@lemmy.ml 2 months ago
Politely agree to disagree and I’ll elaborate. Thanks for your input.
LTH are all marked as such. MABL normal (non LTH) discs such as verbatim sells for less than half the cost of M-Discs have the same physical properties as M-Discs, the protective layers are the same, the recording methods are the same using the same materials. Therefore the longevity is the same or near the same without getting into M-Disc’s ridiculous marketing claims of 1000 years (when NIST and others agree the poly-acrylic protective layer would degrade and decompose after a century or two at most even in ideal circumstances).
/r/Datahoarder has had this argument several times and the consensus so far seems to comes out to the fact that M-Discs were a DVD-era innovation that in the BD era offer no meaningful advantages in technologies.
I’d rather have two BD’s from a reputable company like Verbatim (not fly by night plain white discount bulk BD’s from who knows where) from separate batches bought 6 months apart stored properly than rely on one overly expensive M-Disc that isn’t going to last any longer and probably isn’t made to meaningfully tighter tolerances.
NIST only estimates the lifetime of M-Discs, real world abuse tests on BD’s (non LTH, not even fair to mention those tbh because they’re not in the running) show good endurance that far exceeds DVDs. It comes down to however burning it right and storing it right. A pile of M-Disc left in a window in your uninsulated garage year after year and burned at 16x are not on the whole going to be in a better state in 20 years than a pile of BD-R’s burned at 4x, stored in protective sleeves in a case in a temperature controlled, insulated environment. Add in having a back-up copy and the chances of total data failure on both primary and backup disc and you’re looking at better survivability. NIST numbers generally assume things like storage in archival quality environments such as old salt mines which are a controlled environment, low humidity, neither excessively hot or cool and not subject to shifts in temperature. Most people can’t store things in an environment like that and those who can usually have the finances for a better solution like multiple tape copies and/or continually updating and refreshing hashed/checksumed files and moving on a schedule to new better storage mediums (e.g. keeping files in a raid array in a plugged in NAS, checking for failures regularly, replacing disks and upgrading disks every 5-10 years one at a time).
I wouldn’t trust any media not professionally stored in a purpose-built archival environment and with at least two copies to last more than 25 years without degradation or loss. Anyone trying to store stuff really long-term and cannot afford degradation or loss needs to have a plan to update their archival copies every 15 years or at least do an assessment that often and survey the options as well as the physical and ideally logical state of their chosen back-ups.
finley@lemm.ee 2 months ago
That all sounds like it’s still terrible idea to use optical media for backups