Problem with DD

[Re1L]

Hello everyone. I have a problem with making backup through dd.
Example:
Through PINE installer on windows i installed some image of Linux on SD card.
Then on linux machine through dd command (dd if=/dev/mmcblk0p conv=sync bs=64K | gzip ~/image.img.gz) i made image of this SD card.
Then i copied (gunzip -c ~/image.img.gz |dd of=/dev/mmcblk0o conv=sync bs=64K) image from my file to SD card.
And this doesn't work, system is not loading. 
Gparted cant read what kind of FS using partitions after making copy on SD card.
Has anyone encountered this?

[dukla2000]

Suspect you have a problem with your devices: my RP64 has /dev/mmcblk0 and /dev/mmcblk0p1 etc

[CounterPillow]

If you made a block copy of a running system with the block device mounted, you're doing a very bad thing, as there is no guarantee of that state being consistent in any way while your block copy is ongoing.