Sandisk 16GB SDHC not mountable
christian.rueb at gmx.net
Sun Oct 3 14:49:25 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)
less is installed ;-) I just could not read back what I wrote in. I.e. i catted /etc/hosts but got back only garbage. But as i catted it into the device (not the partition) I could read the contents back from somewhere near (but not at!) the beginning.
So this differs from my PC results
> 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
> > 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
Trying a fs on the whole device did not help either.
It seems like writing onto the card works (partitioning, creating fs) but reading does not (fsck, mount).
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