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Maybe a dumb question, is there some technical reason why the SD card ever needs to be writeable if you’re netbooting? I understand the appeal of not needing a

Maybe a dumb question, is there some technical reason why the SD card ever needs to be writeable if you’re netbooting? I understand the appeal of not needing an SD at all, but if the common failure mode is read-only just embrace it. Speaking of which, why don’t WORM SD cards exist since there aren’t write protect switches on MicroSD cards? For that matter, is there a way to reliably induce the read-only mode without just bombarding an sd card with writes?

wolfgke 9y ago
> Speaking of which, why don’t WORM SD cards exist since there aren’t write protect switches on MicroSD cards? Also "normal" SD cards are not write protected even if they have a switch that is in the write protect position: > https://en.wikipedia.org/w/index.php?title=Secure_Digital&oldid=814403607#Write-protect_notch https://en.wikipedia.org/w/index.php?title=Secure_Digital&ol... "The presence of a notch, and the presence and position of a tab, have no effect on the SD card's operation. A host device that supports write protection should refuse to write to an SD card that is designated read-only in this way. Some host devices do not support write protection, which is an optional feature of the SD specification. Drivers and devices that do obey a read-only indication may give the user a way to override it."
gerdesj 9y ago
No there is no reason for the SD card to have to be writable. You can put / and other filesystems into RAM discs. You can disable swap or run it over NFS and you can get other filesystems over NFS as well, so lots of options. If you pass the correct options to the mount command, you get read only mode (funnily enough it is the ro option)