Problem with the .gz file size ?

• Etcher version: 1.0.0-beta16
• Operating system and architecture: OSX 10.11.6

I make backups of SD cards with this script in the Terminal :

diskutil unmountDisk /dev/disk1
sudo dd bs=1m if=/dev/rdisk1 | gzip -c > ~/Desktop/pi.img.gz

When I try to flash these .gz images, Etcher seems to get stuck at 99% of the process, ETA remans at 2 or 3 seconds, the transfer rate very slowly decreases, until I get the error : “Not enough space on the drive. Please insert larger one and try again”. The same error appears with the uncompressed image file, but without the final slow-down.

However, on the command line, with :

gzip -dc ~/Desktop/pi.img.gz | sudo dd bs=1m of=/dev/rdisk1

there’s no error and the resulting SD card works well. Am I doing something wrong or is there a problem with Etcher ?

[lurch]

Slightly off-topic:

Surprisingly, dd will not complain but only copy the first 15522070528 bytes of the image, and completely ignore the rest!

There is actually a use-case for that - when you’re doing something like dd if=/dev/zero of=/dev/sdc to completely wipe out the contents of a drive. dd is a very low-level tool, which means it’s easy to abuse or get things wrong if you’re not very careful 😉

Back on-topic: Specifically, the bug that was fixed in v1.0.0-beta.17 that @jviotti 's referring to is that previously Etcher would only write images with a size equal to an integer number of megabytes. 15931539456 equates to 15193.5 MB, and Etcher v1.0.0-beta.17 now copes with the extra-half-megabyte on the end https://github.com/resin-io-modules/etcher-image-write/pull/58 .

[lurch]

Nah, I think the snippet you’ve quoted basically says that the output file may not be an exact multiple of the block-size. So the output file will always be the exact size of the input file (the raw SD card in your case), regardless of the block size.

I think My shitty USB/SD card adaptor died may be the cause of the errors in the log you posted 😉 So you were actually seeing two problems at once - errors in your logs because of a shitty SD adaptor, and the “Not enough space on the drive” error caused by Etcher beta16 not coping with half-megabyte sized disk images.

Hopefully both problems will be fixed by Etcher beta17 and a new SD adaptor 😃