Having installed grsync I am about to buy an external memory to back up
my Ubuntu home directory.
For what I do on a PC I don't need much memory. At present there is 5.6
Gb on the HDD. This will increase but probably never exceed 20 Gb.
The smallest and cheapest external disc drive is a 2.5" 250 Gb
I think it is a great idea.
When I run Ubuntu on my work notebook, an 8GB flash key is not only my home
directory, but my root as well.
Flash does wear out (though the onboard controller on the keys should manage
a lot of that issue), and can fail like any other electronics.
It is still early da