[CentOS] Trouble (?) reformatting flash drive to include former U3 partition

Mfawa Alfred Onen muffycompoqm at gmail.com
Sun Jun 14 12:32:19 UTC 2009


It's been a long time since i went back to the basic theory. The
simple truth is that the operating system has a way of reserving some
blocks on the storage media and besides the manufacturers use a
multiple of 1000 as opposed to 1024.

On 6/14/09, MHR <mhullrich at gmail.com> wrote:
> On Sat, Jun 13, 2009 at 11:29 PM, MHR<mhullrich at gmail.com> wrote:
>> Semi-OT?
>>
>> I just got a new SanDisk 8GB flash drive, and, as usual, it came with
>> the U3 software (for Windoze) on a "CD" partition and considerably
>> less than 8GB on the disk partition.  I put it into my WinXP portable
>> and told U3 to delete itself, but I still can't get at the old U3 part
>> of the drive.  I've tried WinXP's format command, disk management and
>> CentOS's fdisk, and nothing will give me more than 7,872,512 bytes per
>> cylinder, times 1019 cylinders yields 8,022,089,728 bytes.  Is that
>> right, or should there be more?  fdisk also reports that the drive has
>> 8029 "MB", or 8029470208 bytes, which is 7,380,480 bytes difference
>> (until it gets allocated into the 8,022,089,728 bytes of the
>> partition) - I'm thinking this is a standard formatting loss.
>>
>> My 4GB flash drive has 4,096,189,440 bytes on it, and twice that would
>> be 8,192,378,880, which is a difference of 170,289,152 bytes, or about
>> 162+MB.  The former "CD" partition (which is invisible, so far) only
>> had 8,645,202 bytes used on it, which leaves a huge amount of room to
>> spare of inaccessible empty space.
>>
>> What am I missing?  Or is that just the way it is?  (The package only
>> says "Some capacity is not available for data storage."  That doesn't
>> really tell me enough.)
>>
>
> By comparison, I also have a Kingston 8GB flash drive, with the U3
> partition removed, and it shows 7916608 1k blocks (in df), whereas the
> 8GB Sandisk only shows 7818752 (so far).
>
> Relevance uncertain....
>
> mhr
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