[HH] Different Mfg SD Cards will not format to same size

[Phil C.]

There is proprietary software used to read the SD card.  I tried a simple contents copy and the software rejected the copy on another SD card.  I could use an editor to read exactly is there, but I  don't want to spend a lot of time fooling with this.

The card came formatted, so I don't know what the raw capacity is. I reformatted the new card and it still came to   3.69GB.
There are other free copy/formatting tools, I'd have to fool with each:
http://www.paragon-software.com/home/pm-express/download.html
http://www.partition-tool.com/easeus-partition-manager/help/resizing-and-moving-partition.htm
This first two I have not read documentation to see what they can do.

This one clearly says it will resize FAT32:
http://www.partitionwizard.com/resizepartition/resize-fat32-partition.html

Supposedly clonezilla in advanced mode may be able to do the job, but I have to make a live cd or flash drive first.

I really want to do this quickly and not spend hours.    
This sort of stuff is the reason I stopped being a .Net C# developer.   Life is too short to waste eons fooling with software.




-----Original Message-----
From: Tom Metro [mailto:tmetro+hhacking at gmail.com] 
Sent: Monday, January 05, 2015 6:16 PM
To: Phil C.
Cc: hardwarehacking at blu.org
Subject: Re: [HH] Different Mfg SD Cards will not format to same size

Phil C. wrote:
> I just can't figure out why the two 4GB SD cards have different 
> formatted capacities.

What is the raw, unformatted capacity?

The difference might be in partitioning options chosen.


> The souce SD has some kind of proprietary header or something in there 
> so that I just can't copy the files.

How did you determine that?

The proprietary bit might be just in the master boot record (MBR). You could experiment by using dd to copy the MBR to a new SD card and see if it is recognized by the machine. (Chances are, if you Google it, someone has already figured this out.)

What is the end objective to your cloning? Do you need the files to be recognized by the machine? Or is there PC software that lets you view the contents of the files?


Mark Komarinski wrote:
> Can you try to resize the FAT32 partition down a touch so it's maybe 
> 3.5GB?  Just be sure to keep the original image :)

Right...on Linux you might clone the original SD card to an image file on a hard disk, mount it with the loop-back device, and then use a partitioning tool to downsize it.

With less capable tools you might need to clone it to a larger USB Flash drive or a larger SD card, then perform the downsize.


> Regular hard drives have the same problems which makes it fun when you 
> try to use different vendors for a RAID array (as in, don’t, and be 
> sure to get the exact same model for replacement drive)

With software RAID you have options. One option is that you partition the drives first. Then you can determine the largest partition size that will fit on all drives. I believe another option is that even when using an unpartitioned drive, some software RAID tools will automatically determine the maximum size that will fit on all drives.

 -Tom