Posts: 141
Joined: Thu Jun 14, 2012 10:40 am

Corrupted SD card

Sun Oct 20, 2013 8:38 am

After a year using my raspberry pi, Im having the following problem:
most of the times, when trying to boot it many messages like
mmcblk0: error -110 transferring data, sector ***, nr ***, cmd response 0x900, card status 0xb00
end_request: I/O error, dev mmcblk0, sector ***
where *** are variable numbers...
sometimes it just boots but I dont know when...
Is there a way to fix it? something like scandisk?

Posts: 917
Joined: Sun Jul 29, 2012 9:06 pm

Re: Corrupted SD card

Tue Oct 22, 2013 8:50 am

I would try with another sd card 2 see if the problem goes away with that.
If that's ok, you could google for the linux fsck command.
The partition you are checking with that should not be mounted. So, you will have to do it on another linux system. You could use a live cd setup for that.
Another option is backupping all your personal stuff from the sd card and reformatting the sd card with one of those special tools for sd cards. That method has the biggest possibility to fix the issue.

Posts: 189
Joined: Tue Jan 22, 2013 8:50 am
Location: berlin, germany

Re: Corrupted SD card

Tue Oct 22, 2013 10:00 am

I've been doing quite a large project using Pis, and had to use the same lot of SD cards.

After lots of trouble, I could only throw a few hundred SD cards to /dev/null and switch to another brand. Half of the SD cards of the "bad" brand had read errors right after first writing to them. Or, they refused to be written right away. The "good" SD cards did expose less space to the operating system, the "bad" ones (of the same nominal size!) were 10% or so "bigger" to the OS.

I had the feeling, that the "good" cards kept some spare "sectors" to replace bad sectors when needed, while the "bad" cards just addressed all the space, bad sectors just being bad.

As SD cards in every day use are usually FAT formatted, this might be working. FAT is such an old file system that it feels responsible to deal with bad sectors. Modern file systems rely on the mass storage device to find and correct errors by itself.

So, I would suggest to save important data somewhere else, and buy another SD card of a different brand.

Posts: 50
Joined: Fri Oct 11, 2013 10:17 am

Re: Corrupted SD card

Tue Oct 22, 2013 10:39 am

My card kept corrupting.

I looked and it was a 'nok'

I am back to using the card that came with the raspberry pi. Fingers crossed its been ok so far

Posts: 141
Joined: Thu Jun 14, 2012 10:40 am

Re: Corrupted SD card

Sat Nov 02, 2013 2:38 am

Thanks for all the detailed replies.
I already tried 2 different sd cards. Both are 16GB SanDisk and are listed as verified.
This problem occurs from time to time and is very annoying. every few months Im creating a new backup...
Is there a way to run fchk from windows? I prefer not to use linux on my system.

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