fdisk /dev/sda = Unable to read /dev/sda

zialien

Hello,
I am attempting to repartition my old 1gig memory stick so that i can use it as a live boot usb for my new toy (eee pc) but I cannot get it to partition.
It currently (to my knowledge) has one partition only as when i put the drive in and look at dev only sda1 is created. On a related note the stick works under windows xp fine, mounts and everything under my gentoo box fine i just cannot use fdisk. Also under Xandros on my eee it does not detect the partition but it does try to mount the device.
When the stick is inserted we get

NeddySeagoon · Posted: Sun Feb 03, 2008 2:46 pm Post subject:

zialien,

Are you sure your memory stick is partitioned at all ?
Many are not - they are organised like floppies with no partition table. Still, fdisk does not throw errors, it just shows rubbish.
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Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

zialien · Posted: Sun Feb 03, 2008 9:11 pm Post subject:

Hello NeddySeagoon,

If it is not partitioned then that is strange. I assumed that because it mounted as /dev/sda1 that there was a partition. It would explain the dd error when i tried to wipe the partition table (something like cannot write). This means though that I cannot use it for boot purposes would that be correct? Or will it just mean the whole thing is the one partition and it somehow gets bootable?

Cheers

NeddySeagoon · Posted: Sun Feb 03, 2008 9:19 pm Post subject:

zialien,

As long as /dev/sda1 is your USB stick, its partitioned an behaves like a hard drive
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

zialien · Posted: Mon Feb 04, 2008 9:07 pm Post subject:

Hello NeddySeagoon,

So I guess this becomes a dead unsolvable topic due to crap hardware?

Thanks Anyways I will just buy another memory stick.

timeBandit · Posted: Mon Feb 04, 2008 9:18 pm Post subject:

Don't run to the store just yet. :wink:

Are you trying this as an ordinary user or as root? You need to be root to repartition a drive, because you need read/write access to the whole-disk device (/dev/sda in your case). A regular user ordinarily has full access only to the partition device(s) (/dev/sda1), which is insufficient.
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zialien · Posted: Tue Feb 05, 2008 7:03 am Post subject:

It was all done as root. I don't run sudo before you ask.

NeddySeagoon · Posted: Tue Feb 05, 2008 6:44 pm Post subject:

zialien,

A couple of things. The kernel has found the partition table - so its there.
Can dd read it?

zialien · Posted: Tue Feb 05, 2008 9:12 pm Post subject:

dd:

NeddySeagoon · Posted: Tue Feb 05, 2008 10:04 pm Post subject:

zialien,

Google has lots of posts with problems with that device but I didn't find any solutions or root causes.
Reads of the what should be the master boot record fail but the kernel gets a partition table.
Thats two pieces of conflicting evidence. It suggests the partition table is not at block zero and the kernel can tell.

You could try multiples of 512 for the bs in dd. Larger flash drives have 4096 byte native block sizes. However, dd should cope with that.
_________________
Regards,

NeddySeagoon

Computer users fall into two groups:-
those that do backups
those that have never had a hard drive fail.

zialien · Posted: Tue Feb 12, 2008 9:31 pm Post subject:

Ok, I have tried 512 - 4096 with the same error. This is all rather confusing.

Any more ideas?