The only truly secure system is one that is powered off, cast in a block of concrete and sealed in a lead-lined room with armed guards - and even then I have my doubts.

Customer needs always come first; everything else is secondary.

对一切数据进行冗余备份，至少要有一个物理硬盘备份和一个云端备份。每个备份都要多于一个。想想要是你弄丢了所有数据、照片、笔记，得花多少钱来找回它们？与遗憾相比，备份很便宜。