28-bit LBA limit and dd

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28-bit LBA limit and dd

by metalevel :: Rate this Message:

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Hi,

I have a question according to the 28-bit LBA limit and the GNU dd tool.

The english Wikipedia states, that Seagate warns, that GNU dd may fail to opperate files/images larger than 128GB due to the mentioned old 28-bit LBA limit. I searched today a lot on the web, but didn't find any hint, whether this affects the current version of dd.

Unfortunately I have no insights in the innards of the GNU coreutils, and how they exactly work.

So, is the current version of dd capable of creating disk images larger than 128GB?
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Re: 28-bit LBA limit and dd

by Pádraig Brady :: Rate this Message:

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metalevel@... wrote:
> Hi,
>
> I have a question according to the 28-bit LBA limit and the GNU dd tool.
>
> The english Wikipedia states, that Seagate warns, that GNU dd may fail to opperate files/images larger than 128GB due to the mentioned old 28-bit LBA limit. I searched today a lot on the web, but didn't find any hint, whether this affects the current version of dd.
>
> Unfortunately I have no insights in the innards of the GNU coreutils, and how they exactly work.
>
> So, is the current version of dd capable of creating disk images larger than 128GB?

dd should be able to stream aribtrary amounts of data.
For seeking etc. it uses off_t internally which is 63 bits on my system

$ printf "%'d\n" $((2**63-1))
9,223,372,036,854,775,807

Your file systems and block devices will have lower limits.

cheers,
Pádraig.