raid5

[Brian Cluff]

Yes, you'll be looking at doing a software raid.

Just curious, what are you needing to get out of a RAID that makes you 
want to do it?  More space, more speed, or redundancy?

You can get certain combinations of all 3 of those but it depends on 
which raid you pick and what settings it has.
Of course RAID can also be a really good way to instantly destroy all 
your data if you don't do it right.

If you are just looking for some safely for your data, I would recommend 
that you start with a RAID 1.  You won't get any extra space out of it, 
but it's a fairly bullet proof RAID option that allows for any of your 
drives to be mounted individually, so its very difficult to loose your 
data without all your drives dying at once.  You also get a little bit 
of a speed boost under certain circumstances.

Brian Cluff

On 7/18/20 7:58 AM, Michael via PLUG-discuss wrote:
> I think I want to start a raid array level 5.
> this is what my google search revealed to me:
>
> If you want to use hardware RAID device, use hot swappable hardware
> RAID device with spare disks. If any disk fails, data will be
> reconstructed on the first available spare disk without any downtime
> and since it is a hot swappable device, you can replace failed device
> while server is still running.
>
> Unfortunately, I am finding it difficult to find how to do a hardware
> array. Everything I'm finding has to do with software array with a
> paragraph about hw array so when I google hardware 'array linux' I get
> results and I get confused. Could someone point me to some concise
> instructions on doing this? I found one promising one on wiki
> (https://raid.wiki.kernel.org/index.php/Hardware_Raid_Setup_using_MegaCli)
> but they wanted a raid controller to be installed on your system
> first....
> Ohhhh .... I think I get it! the hardware raid requires The controller
> which is a pci card. So now I need a software array
>
> is that correct?
> Any concise instructions?