Setting up an extendable software raid 0 in Ubuntu [closed]

I have 8 drives, 4 of which are empty, the other 4 full. If i was to make the 4 empty drives a raid 0, then copy the content of the other drives to this new raid. Can i then extend that array set by adding on the 4 other drives (now empty), or will the content i voted into the existing array be deleted.

When I try this with the hardware raid on my mother-board it warns me the new drive and the current raid will both be erased.

Is there a software raid option that will let me add drives to the array as i add then to my system without losing the data which will always be on the existing array. The new drives so always be empty.

Also, if there is such a software array option, would it be more efficient to add the second batch of 4 drives at once, or 1 at a time.

Or am i limited to having 2 separate arrays, each being 4 discs in size, and any future raid arrays will be however many enjoy drives i have at that point.

I did also look into a JBOD arrays, but was given the same "all drives will be deleted when adding a drive" vibe from the websites i explored.

If I can choose i prefer raid 0 over JBOD, for the striping, and would love to be able to use all the drives i have to create a single array, and be able to add to that array until i run out of SATA ports.

Alsi, if am forced to have two arrays set up, is an onboard (asus) controller likely to be more efficient than a software raid.

I'm on Ubuntu 18.04.1 LTS desktop, if that matters.

I basically need the striping feature if a raid 0 for better efficiency (i don't need parity or duplication, just an extended stay as new drives are added.

Tia

1 Answer

You have a lot of questions there :)

I'm going to try and answer (or suggest a trail of thought) for the following:

Is there a software raid option that will let me add drives to the array as i add then to my system without losing the data which will always be on the existing array. The new drives so always be empty.

Also, if there is such a software array option, would it be more efficient to add the second batch of 4 drives at once, or 1 at a time.

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From what I can see in the mdadm (Linux Software RAID utility) man pages the following applies:

From 2.6.35, the Linux Kernel is able to convert a RAID0 in to a RAID4 or RAID5. mdadm uses this functionality and the ability to add devices to a RAID4 to allow devices to be added to a RAID0. When requested to do this, mdadm will convert the RAID0 to a RAID4, add the necessary disks and make the reshape happen, and then convert the RAID4 back to RAID0.

Perhaps also have a look at this link for a fairly good "guide to mdadm"

I would suggest adding all the extra drives at once. Otherwise you will have to re-do the process 4 times and from past experience I know that any RAID changes can take a significant amount of time.