Если диски ранее использовались, и их разделы смонтированы в системе, то предварительно их необходимо отмонтировать!


Смотрим диски:

# fdisk -l
...
Disk /dev/sdc: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/sdd: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Создаем разделы на дисках при помощи команды cfdisk. Интерфейс у этой программы интуитивно понятен. В процессе создания разделов задаем им тип файловой системы Linux RAID.

# cfdisk /dev/sdc
# cfdisk /dev/sdd

# fdisk -l
...
Disk /dev/sdc: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

Device     Start        End    Sectors  Size Type
/dev/sdc1   2048 7814037134 7814035087  3.7T Linux RAID

Disk /dev/sdd: 3.7 TiB, 4000787030016 bytes, 7814037168 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: XXXXXXXX-XXXX-XXXX-XXXX-XXXXXXXXXXXX

Device     Start        End    Sectors  Size Type
/dev/sdd1   2048 7814037134 7814035087  3.7T Linux RAID

Делаем raid (/dev/md0):

# mdadm --create --verbose /dev/md0 --level=0 --raid-devices=2 /dev/sdc1 /dev/sdd1
mdadm: chunk size defaults to 512K
mdadm: Defaulting to version 1.2 metadata
mdadm: array /dev/md0 started.

# fdisk -l
...
Disk /dev/md0: 7.3 TiB, 8001302822912 bytes, 15627544576 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 524288 bytes / 1048576 bytes

Проверяем:

# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath] [faulty] 
md0 : active raid0 sdd1[1] sdc1[0]
      7813772288 blocks super 1.2 512k chunks

Создаем файловую систему:

# mkfs.ext4 /dev/md0
mke2fs 1.42.12 (29-Aug-2014)
Creating filesystem with 1953443072 4k blocks and 244183040 inodes
Filesystem UUID: xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
Superblock backups stored on blocks: 
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
        4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968, 
        102400000, 214990848, 512000000, 550731776, 644972544, 1934917632

Allocating group tables: done                            
Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

RAID 0 готов, /dev/md0