Creation of imsm container failes. Setting up Inter RST RAID array.

[Robert]

Hi!

I could use some help with setting up Intel hw raid array. I have two, 4 TB drives that I want to use purely for storage (no booting) as a raid 1 array.
I did manage to set them up as a software RAID using mdadm. However, I would want the array to also be accessible from Windows 10 installation. AFAIK to achieve this I need to use hardware RAID created in BIOS by Intel Rapid Storage Technology (RST).

I tried to follow these instructions ([1] and [2]):
$ sudo mdadm -C /dev/md/imsm /dev/sd[b-c] –n 2 –e imsm

It fails:
mdadm: /dev/sdb is not suitable for this array
mdadm: /dev/sdc is not suitable for this array
mdadm: create aborted

Also this does not look good:
$ sudo mdadm --detail-platform
mdadm: imsm capabilities not found for controller: /sys/devices/pci0000:00/0000:00:1f.2 (type SATA)

Some info about hardware:
$ dmesg | grep 1f.2
[ 2.677109] ahci 000:00:1j.2: version 3.0
[ 2.677252] ahci 000:00:1j.2: AHCI 0001.0300 32 slots 6 ports 6 Gbps 0x3f impl RAID mode
[ 2.677254] ahci 000:00:1j.2: flags: 64bit ncq led clo pio slum part ems apst

Controller is set to RAID mode in BIOS also, RAID array has been created (VOLUME 1)

$ sudo mdadm --examine /dev/sdb

/dev/sdb:
Magic : Intel Raid ISM Cfg Sig.
Version : 1.3.00
Orig Family : 66247044
Family : 66247044
Generation : 00000002
Attributes : All supported
UUID : e492be44:10b30ade:b642e816:dd60ca99
Checksum : 0f34c20c correct
MPB Sectors : 1
Disks : 2
RAID Devices : 1

Disk00 Serial : ***
State : active
Id : 00000002
Usable Size : 7814031624 (3726.02 GiB 4000.78 GB)

[Volume1]:
UUID : 5d5fbe08:1c90e2f3:e7896bec:0c7ca70a
RAID Level : 1
Members : 2
Slots : [UU]
Failed disk : none
This Slot : 0
Array Size : 7814031360 (3726.02 GiB 4000.78 GB)
Per Dev Size : 7814031624 (3726.02 GiB 4000.78 GB)
Sector Offset : 0
Num Stripes : 30523560
Chunk Size : 64 KiB
Reserved : 0
Migrate State : idle
Map State : uninitialized
Dirty State : clean

Disk01 Serial : ***
State : active
Id : 00000005
Usable Size : 7814031624 (3726.02 GiB 4000.78 GB)

For /dev/sdc output of --examine is similar.

Hardware specs:
mb: asrock z97 extreme4
cpu: intel i5 4690

qubes-os: 3.2-rc3

Thanks in advance for all your help and suggestions on how to proceed.
Robert

[1] http://www.intel.com/content/dam/www/public/us/en/documents/white-papers/rst-linux-paper.pdf
[2] https://raid.wiki.kernel.org/index.php/RAID_setup#External_Metadata

[3n7r...@gmail.com]

IIUC you want to configure a raid device using your BIOS so it can be recognized by both Windows & Linux.

Read the intro here to confirm this is what you want:
https://help.ubuntu.com/community/FakeRaidHowto

Then go here to read all about Linux Raid (including a blistering critique of FakeRaid):
https://raid.wiki.kernel.org/index.php/Linux_Raid
(Another option that you may consider in the future is a separate file server.)

Fedora-23 should recognize Fake/BIOS-raid devices automatically. Sorry I don't have anything I can test with at the moment.

`sudo fdisk -l` should show /dev/sdb, /dev/sdc, as well as /dev/md[X].

If that's the case, you only need to configure partitions/volumes on your md device:

https://raid.wiki.kernel.org/index.php/Partitioning_RAID_/_LVM_on_RAID
https://www.howtoforge.com/linux_lvm

[Robert]

Dnia Środa, 14 Września 2016 19:44 <3n7r...@gmail.com> napisał(a)

Thanks for the reply!

> IIUC you want to configure a raid device using your BIOS so it can be recognized by both Windows & Linux.

Yes, exactly.

> Read the intro here to confirm this is what you want:
> https://help.ubuntu.com/community/FakeRaidHowto
>
> Then go here to read all about Linux Raid (including a blistering critique of FakeRaid):
> https://raid.wiki.kernel.org/index.php/Linux_Raid

Actually, I did not know that I am dealing with FakeRAID here... Thanks for pointing this out.
> if the 'raid' card or motherboard dies then you often have to find an exact replacement and this can be tricky for older cards
> if drives move to other machines the data can't easily be read
These two points discouraged me completely.

> (Another option that you may consider in the future is a separate file server.)

Yes, I think, ultimately, it's the best solution. I do plan to buy a budget NAS device in the future.

> Fedora-23 should recognize Fake/BIOS-raid devices automatically. Sorry I don't have anything I can test with at the moment.
>
> `sudo fdisk -l` should show /dev/sdb, /dev/sdc, as well as /dev/md[X].

fdisk -l grepped with 'md' does not return anything
However,
$ sudo mdadm --examine --scan
returns:
ARRAY metadata=imsm UUID=e492be44:10b30ade:b642e816:dd60ca99
ARRAY /dev/md/Volume1 container=e492be44:10b30ade:b642e816:dd60ca99 member=0 UUID=5d5fbe08:1c90e2f3:e7896bec:0c7ca70a

but when I check /dev/ contents there is no /dev/md/, also I cannot attach (there is none) md device to any VM, only /dev/sdb and /dev/sdc

> If that's the case, you only need to configure partitions/volumes on your md device:
>
> https://raid.wiki.kernel.org/index.php/Partitioning_RAID_/_LVM_on_RAID
> https://www.howtoforge.com/linux_lvm

I think, I'll stick with software RAID. It blows, because I'll have to keep a separate hdd to transfer bigger chunks of data between qubes and windows.