SD Card 8GB not same as 8GB

[Gert]

Hi All,

8GB from one SD card can't be imaged onto an 8GB card from another manufacturer!
I wanted to do a 1:1 image replacement of an SD card that had gotten old and had started to cause crashes of the RPI.
Old card is 'Transcend 8GB SDHC'. New card is Sandisk 'Ultra SDHC Card 8GB'.
Following procedure fails:

1. Backup image from old card to W7 PC using win32DiskImager

• Insert new card into PC and attempt to write image

This gives 'Write Error: Not enough space on disk: Size: 15759360 sectors Available 15523840 sectors Sector size: 512'

So how can I image the old backup onto the new SD card? (If ever)

Cheers,
Gert

[Rive]

First, you may get the capacity you need by 'cleaning' the sdcard, if not see below.

To clean, open command prompt as admin (in search, type cmd) type diskpart (then enter to execute each command), then type list disk, then select your disk...if it is disk 2, you type select disk 2, then type clean. then type exit then again type exit. Now run diskimager as admin, and write image.

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Go get a 16GB or 32GB is my suggestion. 8GB is just asking for trouble with limited storage capacity. I wouldnt waste my time trying to shrink the image.

If in the US, Bestbuy has the 32GB HC-1/UHS-1 Samsung for $11.


If you are dead set on using that 8GB sdcard, see;
http://sirlagz.net/2013/03/10/script-au ... downsizer/

[Gert]

@Rive,

Thanks for the input. I solved the issue by using a lnx box to transfer the image rather than the win32DiskImager.
Using 'dd' nicely transferred all the data and gave a small msg at the end that it couldn't write the last sector. But that wasn't critical anyways.

The same issue might pop up with any size SD card if cards from different manufacturers truly have different sector count.

Cheers,
Gert

[rpdom]

The same issue might pop up with any size SD card if cards from different manufacturers truly have different sector count.

Cards from the same manufacturer can have different sector counts.

Even cards from the same batch can have different sizes. It depends on the individual card as to how many bad blocks may have been mapped out during the manufacture and testing process.

[B.Goode]

The tiny print on the back of the packaging for a SanDisk Card says:

1GB = 1,000,000,000 bytes. Actual user storage less.

On the back of a Kingston pack it says - in equally tiny print:

Some of the listed capacity on a Flash storage device is used for formatting and other functions and this is not available for data storage. As such, the actual available capacity is less than what is listed on the products.

I don't have a Transcend pack for comparison, but I'd be surprised if it didn't have a similar 'health warning.'