Manual copy of files between SD Card is NOT the right way.
Many times we may want to migrate the files from an existing microSD card to a new microSD Card for various reasons like speed and storage size. If the SD card has been used just for media files then copying them manually should not be problem. But when it comes to system level files manual copy will not work as some hidden files used by the system will be ignored. Due to this your device with new microSD card may not work as you expected.
This is more applicable for Smart Phone devices and IOT devices like Raspberry PI which uses the microSD Card. When you explore the file system of microSD card of an Android device, it will have lot of system files which has been used by the OS and also the Apps. Simply swapping the SDCard by copying the data may throw errors or your application may not be listed in the launcher.
Recently i upgraded the microSD Card for the Raspberry Pi 3 from 8GB to 16GB Class 10 Sandisk Ultra. Since all the OS files of Raspbian are in the 8GB card i was looking for a tool to do the work of a COPIER similar to DVD/CD Copier. I came across a utility called “HDDRawCopy1.10Portable.exe” which does the job of exactly mirroring the original SD card. The only issue is it even copies the storage size of the source sdCard. In my case after successfully copying to the 16GB Sandisk, it was showing as 8GB. We can simply use any of the disk tools to expand the filesystem and reclaim the remaining storage. The good thing is Raspbian contains a default utility to expand the filesystem and i used to get back the storage.
I loaded back the new SD Card to the Raspberry Pi and it boots in 15 seconds and its really faster with Class 10 SD card. It never knew that i was using the new SD Card as i have copied the entire filesystem of the original SD card .
Thanks for reading.