# cannot mount memory card

## Adel Ahmed

I formatted my 64GB using fdisk, created the ext4 FS and tried to mount

mount /dev/sdb1 /mnt/

mount: wrong fs type, bad option, bad superblock on /dev/sdb1,

       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try

       dmesg | tail or so.

I just bought the memory card so this is my first formatting

here's my dmesg(or at least as much as I could read of it):

http://pastebin.com/LjcRssW8

I'm clueless to what to do now

thanks in advance

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## eccerr0r

Ha.  That dmesg is very helpful indeed, no?

All jokes aside, yes agreed, that dmesg didn't seem to say much, other than the kernel is having trouble accessing the disk.

So did you fdisk this media in linux on the same machine?

When I see something like this happen - able to at first fdisk, then see stuff like this in dmesg, usually that media is kind of broken or not compatible with the system...  Does it still work in another device?  Another OS?

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## Adel Ahmed

well I did use fdisk on the same machine, I tried to format the card on my android device(exfat), the mount was successful, however out of the 64 GB I have I am only capable of using 16 GB before I start getting errors while copying, so it might indeed be a corrupt device, how can we check?

thanks

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## eccerr0r

You probably should thoroughly check it out on another machine to make sure the media is good.  It may just well be that it's not electrically compatible with your reader.  Perhaps try a different one?

One thing I've noticed is that some flash media the manufacturer cheaped out and just made the first few blocks have high endurance with the rest of cheap endurance.  So that if you use any filesystem other than FAT, results can be unpredictable.

This is not including the cheaters that put in less memory than stated, and hope they're long gone before you reach that capacity...

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## v_andal

This could be problem with "huge_files" support in ext4. Kernel has to be compiled with CONFIG_LBDAF for it to work and it is enabled by default in ext4.

Though it could be anything else as well.

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## Adel Ahmed

I can't see the option in my kernel config

it says this module has a dependency of:

block(check) and !64BIT(I have this enabled)

it also says in the module's description:

Support for large (2TB+) block devices and files  

so is this what we might be looking for? I indeed don't have it enabled

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## eccerr0r

I thought the "huge files" option that lets the kernel deal with files that are over 2GB.  Since you can get to 16GB without problems, I'm not sure if this is the same problem you're seeing.  You certainly should not be seeing the "can't access block X" - the kernel should just return invalid operation, disk full, or something to that extent to the application trying to access the huge file.

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## NeddySeagoon

blakdeath,

It seems to be a hardware issue.  [

```
27034.799451] Buffer I/O error on device sdb, logical block 16384
```

is a bad sign.

It may be the card the card reader, or if the reader is a USB device, a lack of power caused by having other devices connected to the same USB root hub.

A self powered (not USB bus powered) USB reader should be OK.

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