Easy question about backups

UDb23

@tmntturtlguy said in Easy question about backups:

I have had instances where a new SD card has less available space than the original card, but never had issues with disc imager creating an image larger than the original.

I have the latest v1.0. I can confirm what you said.

ruckage

@udb23 @TMNTturtlguy

I wonder if it only affects certain brands of SD card as that could explain why it affects some people and not others.
@BobHarris what SD card were you using out of interest?

BobHarris

@ruckage A Sandisk 16 gb, the branding has worn off so can't tell you more specifics.. I can't remember when I bought it. Maybe 5-7 years ago.

@UDb23 Thanks, I will check out RPi clone!

@TMNTturtlguy I might try that some day (different disk imager), but right now I don't want to start all over on a new build in case my backup doesn't fit again on my 16 gb card.

dogeymon

Thanks everyone but this issue is totally resolved....thanks. 4.3 seems really cool!

BobHarris

So today I did some testing. I wanted to see if a different sd card had the same issue (not being able to write the backup image to the card it came from).
I used a Sandisk ultra 32 gb class 10 card. First I formatted the card using SDFormatter 4.0 (Full (overwite) format, size adjustment ON). Then I wrote the Retropie 4.3 image to the card and inserted it into my Pi 3B. I randomly put a few games on there and installed Dosbox. I shut down the Pi and made a backup image using Win32 disk imager 1.0. The image size was 31.104.958.464 bytes.
I always had difficulties getting rid of the Linux partition on the sd card, using Windows based utilities, so I put the sd card into my Sony camera and formatted the card. Afterward I checked how much the available space was on the card: 31.092.277.248 bytes. Total capacity: 31.092.375.552 bytes. (=less than the backup image).
Then I formatted the card again using SDformatter (Full (overwrite), size adjustment ON). Now the available space on the sd card is even less: 31.087.067.136 bytes. (Total capacity: 31.087.198.208).
When I try to put the backup image on the sd card win32 disk imager says: 'More space required than is available. The extra space DOES appear to contain data. Continue anyway?'
So it the problem does not seem to be caused by the sd card. Maybe I mess up the formatting process?

mitu

@bobharris How about if you write the .img directly on the card - no partitioning/formatting involved ? The image file already contains a filesystem and partition structure.

BobHarris

@mitu So basically at this point you are saying I should just ignore the warning 'more space required than is available' and continue anyway?

mitu

@bobharris you could give it a try, but to check I think you might need to a fsck from the OS restored after backup to check if the filesystem is ok.

TMNTturtlguy

@BobHarris since you put it in your camera to reformat did you make sure it reformatted to fat32

BobHarris

@tmntturtlguy Yes, I'm sure.