Hello!

I originally posted this on Kubuntu Forums, but so far no one could help me with this, so I decided to ask here, as it is probably the most active and professional Linux forum.

Here is the link to my post on Kubuntu Forums with screenshots:

https://www.kubuntuforums.net/showth...T-RAID-O-array

And here the problem described:

1. I have a gaming laptop - GT75 Titan 8RG.
2. It has an Intel CM246 chipset and M.2 SSD Combo (NVMe PCIe Gen3/SATA) with two Samsung SSD drives PM961 MZVLW256HEHP combined together into a firmware RAID 0 array.
3. I divided this RAID 0 array into two equal partitions and installed Windows 10 Pro 64 bit on one of it – without any problems.
4. The other partition is meant for Kubuntu 19.04., but sadly I cannot make it to see the array, and that’s the part in which I need help.

I did some reading on RAID volumes under Linux, I tried to get a little bit inside Intel Rapid Storage Technology (Intel RST) in Linux document, and mdadm manual, but obviously I lack the know-how. Kubuntu doesn't detect the array, it even doesn't detect the SSD drives which are its components – lsblk command does not reveal them, but lspci | grep RAID shows that my system has RAID configured. Mdadm seems not aware of my array...

Is there a way I could install Kubuntu 19.04. alongside Windows 10 on my RAID array without destroying Windows installation? Many people on the Internet advised others to assemble a RAID array with mdadm, but my array is already assembled and I don’t want it to be destroyed.

It’s been a while since I messed around with dual boot windows and firmware raid. However, the tool you want is dmraid. It should recognize intel’s firmware raid and allow you to access the drives. Setup and booting off dmraid used to be... uncertain; it would be better to have a separate boot drive. There’s a tutorial for Ubuntu, albeit a bit old.

Thanks. Guess its probably related to the intel video chip/driver combo in my laptop. Doesnt matter what distro or desktop environment, they all work the same. Oh well.

Thanks for your reply mostlyharmless.

According to Intel Rapid Storage Technology (Intel RST) in Linux document dmraid is deprecated, and the better tool for this purpose is mdraid. Unfortunately I don't know how to make it see my array. Any hints on this?

I am unfamiliar with the MSI laptop but dmraid as far as I know is just for fake RAID. Since there is only one drive it looks like a real hardware controller and no special driver is required.

You need to select something else in the installer and associate sda2 as the / partition. Normally you would just leave unallocated space and let the installer create whatever partitions it does.

The downside to RAID 0 is if you loose one drive you loose everything which is Windows and linux in you case. The downside to hardware RAID is if loose the controller or computer you need the same hardware to recover or always have a current backup.

Guess you could try some other live media.

Could be a bios limitation maybe??

Hmm, I finally decided to check the drive part number (MZVLW256HEHP) and it looks they are 256GB drives so RAID 0 would only be 512GB not 1TB.

My laptop has three hard disk drives - 2x SDD 256MB each combined in one RAID 0 (Intel RST) array, which according to Intel's document and Arch Linux wiki is a firmware RAID (aka fake-RAID), and one HDD 1TB. Not only Kubuntu, but also Manjaro don't recognize my array, they event don't "see" any of the disks in the array.

What does:

mdadm—detail-platform

give as output?

Check your BIOS settings to make sure the Option ROM for raid is active.
I’ve got a machine with an intel RST, I’ll try to get around to checking what it shows for me.

Checking on a HP Z220, using Ububtu 17.10 gives

Note: I have no RAID active on this machine, so the output is normal. The Storage option in bios says AHCI/RAID. The chip set is intel C216. Hope this helps somewhat.

I've attached a screenshot with the output to my reply.

Attached Thumbnails

   

I see from your other thread (the kubuntu.net one) that AHCI in bios solved your visibility problem under lsblk. If you boot Windows 10 with AHCI instead of RAID/RST in bios, what happens? If it boots, then I’d run the intel RST app and see what it says about the array. If not, then, you’re probably better off starting from scratch. You might be able to have your RAID 0 setup with AHCI in the bios, Windows 10 handling the raid in software (ie Dynamic Disks) and mdadm assembling the now visible disks.

Odd that my BIOS says RAID/AHCI, and yours splits them into two options. Clearly the RAID/RST option in your MSI bios is incompatible with Linux, given the drives aren’t seen at all. Ah well, this kind of frustration was one of the reasons I stopped using RAID, particularly firmware RAID.

Edit I’m unsure whether Windows can boot off a dynamic disk array

I've tried that - the system won't boot, it returns to UEFI/BIOS. One guy on the Web stated, that Linux won't detect drives with RST enabled and it has to be AHCI mode, but I'm not sure if that's the truth ---> look at the last post in this thread:https://linustechtips.com/main/topic...mment-10795630

Found this Red Hat bug report: https://bugzilla.redhat.com/show_bug.cgi?id=1405321

I have Mobile Intel CM246 Chipset. I begin to think it's an issue with chipset-driver support, as Kubuntu (but also tried Manjaro) seem not to detect information from OROM.

My only other suggestion is to contact the manufacturer and/or make sure you’ve got the latest BIOS update. If though do, then if the maker has a forum, you can post there to see if anyone has a patch. That worked for me with ASUS on an issue with VT-d.

One of the first things I do when buying new laptop is updating it's firmware and BIOS, so both are up-to-date.