Sandisk 16GB SDHC not mountable

Alfa21 freerunner at my.is.it
Sun Oct 3 13:44:33 CEST 2010


2010-10-03 at 11:16 Christian Rüb

> > cat plaintextfile.txt > /dev/mmcblk0p1
> > less -f /dev/mmcblk0p1
> 
> I could not read it back, but using /dev/mmcblk0 it showed up somewhere near the beginning (it was cat to /dev/mmcblk0p1 though)

mmh... maybe less is not installed by default, sorry :P
ok, near the beginning maybe after the 512 stuff of mbr and the partition table if p1 is at the beginning of your device, it's ok and regular thing.
(you'd imagine your device as a long tape with one thing after each other)

strange you are not able to read the p1 but only the whole device

> 
> > you should be able to read your contents of the original input file.
> > if you fail to less it on the FR, try the second command on your PC.
> 
> showed up at partition start

right

> I saw the contents only once and about at the same place when catting it to /dev/mmcblk0p1 (Freerunner)
> Once at the beginning and once about where 1 partitions starts (PC).

right, once at the beginning of the whole device and one where was the beginning of the old p1
(data remains there until overwritten with new data, usually it's never cleared)

> same result :( (Freerunner)
> On my PC FAT32 and ext3 work ...

also with fat32 directly on whole device? (no partition table)

> Note that I booted using Qi and system is on NAND (kernel 2.6.29)

sorry but I do not know if 2-4-2 or default change anything, I use qi too but the plain one and with 8GB uSD.

> Now even fdisk does not find the card anymore. As from the wiki I thought the card would work :(

me too.. I was about to buying a 16GB one! :P
btw, maybe you should clear your uSD...

dd if=/dev/zero of=/dev/mmcblk0 bs=512 count=2048

WARNING: THIS COMMAND IS REALLY DESTRUCTIVE!!!
(this will totally blank the first 1MB on your device, so mbr, partitions, some data &Co.)
double check the of= value before return!!!

try to build all your tables on a real PC instead of FR

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