backup photos in google android

strategies

• backup HDD
• delete device only
  • if possible, I should delete the only older ones than half year ago

operation

backup HDD ( ubuntu )

• http://askubuntu.com/questions/342319/where-are-mtp-mounted-devices-located-in-the-filesystem

cp -r /run/user/${USER}/gvfs/${YOUR_PATH} ${DEST}`

delete device only

According to the below link, I can do it on Adroid

• https://support.google.com/plus/answer/1304803?hl=en-GB

if possible, I should delete the only older ones than half year ago

It is partly possible. If I operate by manual, I can do it :) Or if I can experiment it, it's done by script… but it's too much.