Unable to copy files to /sdcard Due to a configuration error I made combined with an OTA update (Android 4.1.2), I had to re-unlock my bootloader to regain root on my GSM Galaxy Nexus. This process wipes the entire phone, including /sdcard. When I restored from backup, I discovered that only some of my files had been included in my most recent backup and subsequently restored.
I have a slightly-older complete backup consisting of the individual files copied onto my computer. However, I can't restore them.
I first tried adb push (note that I'm using Linux and do not have access to a Windows box at this time):
$ adb push . /system/sdcard0
push: ./.estrongs/cache/visit_history-journal -&gt; /system/sdcard0/.estrongs/cache/visit_history-journal
failed to copy './.estrongs/cache/visit_history-journal' to '/system/sdcard0/.estrongs/cache/visit_history-journal': No such file or directory

If I delete the file mentioned, I get the same error for the next file. Note that this is a nonsensical error, as the only possible way for the file to even be attempted is for it to exist. It's annoying when error messages are themselves incorrect.
Next, I fired up DropBear SSH on my phone, started up the server and connected via SSH. So far, so good. But when I tried to use scp to copy the files across...
$ scp -r sdcard0/ root@192.168.2.11:/storage/sdcard0
Welcome to DropBear SSH Server!
root@192.168.2.11's password: 
sh: scp: No such file or directory
lost connection

Grr.
I tried to use a GUI method and use a file manager to copy the files. If I use the USB computer connection settings, I have two options: MTP or PTP. When I use MTP my file manager (Nautilus) can't even list a directory on my phone. The backend just times out. When I use PTP, I can only see camera-related folders. I can copy individual files, but when I try to copy everything, I get an error stating that there's not enough space and that 5 GB more is required. Obviously there's enough space, because what came off the &quot;sdcard&quot; must be able to fit back on.
What gives? Why is it so difficult to move files from my computer to my phone?
Update
After reading some related questions, I was reminded of FTP. I installed an FTP server on my phone and the files are curently being transferred. Of coures, I never thought of FTP earlier since it's obsolete technology and I haven't had a use for it until now for years.
So, my question changes to this: Why did the other methods, which are superior to FTP, fail?
Originally posted by @ott-- in the comments, this answer did the trick. I'm posting it as an answer since ott-- hasn't.


  Isn't the target named /sdcard or /storage/sdcard and not /system/sdcard?