2_4TB_Disks

detected as /dev/sda and /dev/sdb in dom0 Alpine (after it was working successfully).

As we don't have a hardwarde RAID card - using mobo's RAID was no good ..

also tried setting BIOS for UEFI RAID (with Windows 8/10 OS setting and CSM ...compatibility thing disabled) ... fucker didn't boot.

Then tried the Intel old school ROM RAID ... reverting the two settings from above...still NVME not detected.

so made the SATA settings in BIOS back to ACHI rather than RAID... also as no performance gain from BIOS RAID - will use raid in linux.

USING INSTRUCTIONS FROM: http://wiki.alpinelinux.org/wiki/Setting_up_a_software_RAID_array

however, I'm setting up RAID0 --- ABORTED AND MOVED TO RAID 1: REFER TO STORAGE_XEN

modprobe raid0

cat /proc/mdstat

gdisk /dev/sda

<-- make new parition accepting all defaults except type: type code is fd00 - this is LINUX RAID AUTODETECT.

<-- same on /dev/sdb ...but had a small NTFS parition that I deleted.

gdisk - how 0xfd00 translates to MBR value of autodetect: http://www.rodsbooks.com/gdisk/walkthrough.html

https://raid.wiki.kernel.org/index.php/Partition_Types

now trying to create RAID0:

mdadm --create --level=0 --raid-devices=2 /dev/md0 /dev/sda1 /dev/sdb1

first sign of trouble:

mdadm: cannot open /dev/sdb1: No such file or directory

ls -l /dev/sd*

shows that /dev/sda1 exists ...but block device for /dev/sdb.

blockdev --rereadpt /dev/sdb

...doesn't help

cat /proc/partitions

.... this shows sdb1 present....

hmm...why block device not created??? some more reading into the issue: http://unix.stackexchange.com/questions/56516/dev-sdb-no-such-file-or-directory-but-dev-sdb1-etc-exist ... interesting that Alpine (and so is my fedora 22) is using devtmpfs to populate /dev on boot.

also - can try creating new device mknod <><><><>...but didn't want to experiment too much...so I REBOOTED.

ok - so the reboot created /dev/sdb1.

then running the create command said that the device is already a part of raid ...etc... ignore this and say Y.

this creates /dev/md0...

rest follow the instructions re loading modules, starting the mdadm-raid service at boot and updating the /etc/mdadm.conf file.