On Fri, 6 Apr 2018 08:35:20 +0200 Didier Kryn <[email protected]> wrote: > Le 06/04/2018 à 03:33, Steve Litt a écrit :
> SD cards (not even speaking of micro-SD) have a higher density > and can be put in readonly mode. They are certainly more expensive, > but re-usable. Reusable isn't always a plus. If I had a nickel for every reusable backup I saw prematurely reused. Floppies, tapes, zip drives, external hard drives, thumb drives, they're all way too likely to "oops, I just backed up over my latest backup, and the backup didn't take. And if you're reusing media for anything important, you need to create and stick to standards for when you consider them too old and crush them and throw them out. > CDs and DVDs have several different standards and most drives > cannot read all of them. Show me any consumer optical drive that can't read iso9660, no Joliet, No Rock Ridge, no El Torito, just iso9660 with 8.3 filenames (easy to do if the files are really inside .tgz's. One can argue about the convenience of .tgz's on a backup medium, but it works very well at making your old stuff available at restoration. > I've also experienced that CDs written on a > drive couldn't be read from another one and vice-versa. Drives wear out, and often the first thing to go is their interoperability with others. If you're using a drive to record important stuff, don't let it get more than 3 years old. They're cheap. > CDs and DVDs > are OK for archiving data for a few years; I don't trust them for > longer. Except for paper, what COULD you trust for more than a few years? Thumbdrives? Give me a fantastic break, those suckers have self-destructed on me in record numbers, ESPECIALLY when left in that windows format they come in. Tape? Well, maybe if you recorded it on a $10K machine and kept it in metal cans in climate control. External hard disks? Those things are meant to be kept running, and from what I hear if you rarely use them, they can get stuck kind of like those old Mazda rotary engines. Let's talk about "a few years": http://troubleshooters.com/lpm/201408/201408.htm#he_who_laughs_last I had 16 year old CDROM backups that were provably bit for bit the same as I recorded them. > > For what concerns an installer, a few weeks is longer than what > you need and there's nothing precious. Better use an USB stick or an > SD card if you can download the content from the Internet. > > I think CDs are mostly good for usages in which it matters that > the support is inexpensive, like commercial videos. But also, of > course, when nothing else is available. I go the opposite way. I use thumb drives for unimportant stuff I'm storing for a few weeks, or for that sneakernet we all deny ever doing. As bootable thumb drives, it's also nice that you can store stuff like drivers on them so as to not do tons of work, over and over again, when you reboot. But if I want to keep something for a long time, and that thing's important, and especially if it's important it not get into anybody else's hands, I go optical every time. SteveT Steve Litt April 2018 featured book: Troubleshooting Techniques of the Successful Technologist http://www.troubleshooters.com/techniques _______________________________________________ Dng mailing list [email protected] https://mailinglists.dyne.org/cgi-bin/mailman/listinfo/dng
