On Tue, Dec 24, 2019, 15:29 Patrick O'Callaghan <pocallaghan@gmail.com> wrote:
On Tue, 2019-12-24 at 14:47 -0500, Javier Perez wrote:
> Hi
> I have my /home partition on a 2TB HDD drive about half full. Should be
> doing regular backups but not in the habit.
>
> What is better?
> A. Purchase a second 2TB to create a Raid1 mirror or
> B. Purchase a second 4TB drive for backup purposes.

These are two different things with different objectives.

Understood. But in order of importance which would go first? Seems to me like backup should take precedence over Mirroring the data if I look forward to preserve it.


> If case B, should I get a USB3.0 adapter or similar so that I could just
> plug the HDD, let it do the backup and unplug and store it? Or is it better
> to install it on another networked pc and do it through the network?

Either. I use a NAS on my LAN, but it's an old machine with only
100Mbps Ethernet and an obsolete version of Debian. I don't want to buy
a new NAS so I'm seriously thinking of just using a local disk, which
would also be easier to configure.

Your preferred backup software may be important, e.g. s/w that assumes
the backup is on a directly-accesible filesystem can really hammer your
network if you just mount the remote drive with NFS, even if it's just
verifying that nothing has changed.

> Is there a better, easier, less troublesome option to keep the data safe
> that does not involve the cloud?

You need to give more detail of your exact requirements, e.g. how much
data? How often do you want to back it up? How long do you want to keep
it? Are you backing up multiple machines or just one? If the former,
are some of these running Windows or other non-Linux software?

poc
Mine is an all linux network. 
The data exist on two machines. Machine A has about 500GB
Machine B has about 1T but it is mostly my CD and DVD collection. if something happens to it I can always rip it again (assuming the original media did not go kaput). 
Machine B is a "like to have". Machine A I'd rather try not to lose. 
JP