Its not just significant magnetic field ( apparently we do have geo magnetic storms that corrupt data) it is that assigning the 1 /0 bit is not permanent. The 1 or 0 you store fades with time as it wants to lose its assigned magnetism. You might be fine for 10 years, or you might lose a critical bit corrupting a file. it is why archival experts suggest if it is critical data stored offline you need to store on two or more different mediums, because "1 copy is not a backup". Anyway, we are getting deep in the weeds of data entropy and recovery and I think your original comment was meant as being helpful to the lay-person...whom may not actually care to much if they lose a file or two, unless it is a crypto wallet key--i would trust those M series BluRay archival format since the laser alters the disk, but printing out on paper as another copy

[–] psud@lemmy.world 1 points 10 months ago (1 children)

I must have been lucky with my 286's 20MB hdd

[–] BCsven@lemmy.ca 1 points 10 months ago (1 children)

You definitly have been. I have not been so lucky. Lost various data on 10-15 year old drives ( stored in climate controlled basement ) , nothing critical, but enough to prompt me to do regular full copy off and back on process as a refresh

[–] psud@lemmy.world 1 points 10 months ago* (last edited 10 months ago)

I probably should take another image of the 286 and diff it against the earlier backup

And if I time travel, I'll put the key on a hard drive, tape, DVD, and archive quality dvd