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[LUG]Re: MicroSDXC problems

 

On Monday, 5 December 2022 23:52:55 GMT Eion MacDonald wrote:
> 
> A long time ago i had a SD card lock up like this as 'read only'.
> 
> I think is was due to way I disconnected it from computer.

In Debian (and presumably people with similar kernel settings) the default 
behaviour for FAT file systems is to remount them read only if any errors are 
encountered.  See "errors" in "man mount" --  "errors=remount-ro"

This is perhaps what people are seeing if suddenly such a device is apparently 
read-only.

Whilst it may be a sign of decaying hardware, it might also be a power cut or 
a lousy IOT device behaviour, so an fsck always worth a try (but sounds like 
OP has tried reformatting, although if it is lousy IOT device it might be 
breaking it each time it is used or each time it is used beyond a given 
boundary, maybe lock it read-only deliberately when done writing to rule this 
out if possible).  

Anyway the error and remount should be in the kernel log (/var/log/kern.log on 
most distros).

In most cases if you tell it you are removing the device it will flush 
outstanding changes and leave the file system in a decent state, you shouldn't 
have to power off for microSDXC hot plug, although I don't have much use for 
them, mostly car SatNav updates and then they have locked it to a specific 
brand (the swines), and cameras that don't play nicely over USB (non-left 
here).



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