what metadata is it Raspberry PI thinks I should copy?

Question

I was just reading an installation instruction for raspbian https://www.raspberrypi.org/documentation/installation/installing-images/linux.md

when I read this command dd bs=4M if=2020-02-13-raspios-buster.img of=/dev/sdX conv=fsync

I understand this command, conv=fsync, ok we're coying metadata. My question or concern is that for a fresh install, why would I want or need meta data. Which metadata specifically. What data is getting passed along? I know this command would work just fine without conv=fsync, Im just curious what it is the Author seems to think I need to pass on using this argument.

Answer 1

Not metadata, "file sync." It's an option for dd, not a command, and it makes sure that disk output is flushed to the file system as opposed to being buffered by the OS before dd exits. (It does also make sure the file system metadata is up to date with respect to the dd operation.)