Linux Lite Laptop with RAID (part 1)

[kpanic]

So... Many old laptops have a CD/DVD which nobody uses any more. Optical media is becoming old...

But since the laptop may still have an optical drive, why not replace it with a secondary hard-drive?
This gives you many possibilities. You may partition it and use it for documents, music, movies and so on.

One possibility is to add redundancy to your system by creating a RAID1 volume. This means that
in case one of the hard-drives fails / breaks, you will not lose the data in that volume, since RAID1 mirrors
all the data to both disks.

So, how to do it?
First of all, you cannot do it if your first (primary) hard-drive is full, meaning that you cannot add a new partition in it.
(You can add a new partition if you have for example a separate /home partition - then you may copy all of it's contents
into some temporary location, say /tmp/home, then unmount it and use gdisk to use it as RAID mirror, see below ).

BUT: The best way to achieve this, is while doing a fresh LL installation, use 'Do something else' partitioning option and
leave some space unallocated (free, not partitioned space), eg. 16G for example.

First you need one of these: https://www.ebay.co.uk/itm/Universal-2-5...8016235485

You may buy one in a local store or anywhere you want, I bought mine from China since they are very cheap.
Then you also need the secondary HD, which is a standard 2.5" SATA HD. The capacity does not need to be the same
as in your primary HD.

Once you have both, the caddy and the hd, you may then remove the CD/DVD and replace it with the secondary HD.
It's not hard to do. If you have ever played with LEGO bricks, you should be able to do this in a couple of minutes.

Once you have the new HD installed, boot your Linux and choose which files are the most important to you.
For me, they were all the files in my Documents folder, so I chose to create a RAID1 for them.

Let's assume you want to have RAID1 redundancy with your Documents folder too. Then you would first create a
new partition to your new hard-drive:

Start console (if it's not yet open) and command

Code:

sudo su

First prepare your new hard-drive:

Code:

gdisk /dev/sdb

Type 'p' to see the capacity of the disk and verify that it is the new disk

Code:

Command (? for help): p

You will see the Model of the device and it's capacity. If they are correct, you may proceed, otherwise press 'q'.
Then create a new partition which is equal in size as your unused space in the primary disk or less than that.

Code:

Command (? for help): n

Code:

Partition number (default 1): 1

When it asks the 'Last Sector', type the amount of Mega or Gigabytes, that you have unused in the primary disk:
Example, if you have 16G or more:

Code:

+16G

When it asks the Hex code, type 'fd00' and press 'ENTER'
Then press 'w', ignore warnings the new disk is ready for RAID.
Just inform kernel about it, by commanding:

Code:

partprobe /dev/sdb

To be continued in part 2...