Raid6_disk_subsistem

details about the Raid installation can be read here This stand shows the installation of Raid6 with check.

Raid6 assembly description in vagrantfile

add disks to Vagrantfile

:sata6 => {
                          :dfile => './sata6.vdi',
                          :size => 250,
                          :port => 6
                  },		

install mdadm and smartmontools hdparm gdisk

yum install -y mdadm smartmontools hdparm gdisk

overwrite zero disk blocks

mdadm --zero-superblock --force /dev/sd{b,c,d,e,f,g}

create raid 6, l - type raid

mdadm --create --verbose /dev/md0 -l 6 -n 6 /dev/sd{b,c,d,e,f,g}

create raid config

sudo echo "DEVICE partitions" >> /etc/mdadm.conf

sudo mdadm --detail --scan --verbose | awk '/ARRAY/ {print}' >> /etc/mdadm.conf

create markup on Raid sudo parted -s /dev/md0 mklabel gpt

create partitions:

sudo parted /dev/md0 mkpart primary ext4 0% 16%		
sudo parted /dev/md0 mkpart primary ext4 16% 33%		
sudo parted /dev/md0 mkpart primary ext4 33% 49%
sudo parted /dev/md0 mkpart primary ext4 49% 65%
sudo parted /dev/md0 mkpart primary ext4 65% 81%
sudo parted /dev/md0 mkpart primary ext4 81% 100%		

we create directories for the subsequent installation of partitions

sudo  mkdir -p /raid		
sudo mkdir /raid/part{1,2,3,4,5,6}

create a file system

sudo mkfs.ext4 /dev/md0p1
		sudo mkfs.ext4 /dev/md0p2
		sudo mkfs.ext4 /dev/md0p3
		sudo mkfs.ext4 /dev/md0p4
		sudo mkfs.ext4 /dev/md0p5
		sudo mkfs.ext4 /dev/md0p6

add auto-mount to fstab

    sudo echo "/dev/md0p1 /raid/part1    defaults 0 0" >> /etc/fstab
    sudo echo "/dev/md0p2 /raid/part2    defaults 0 0" >> /etc/fstab
    sudo echo "/dev/md0p3 /raid/part3    defaults 0 0" >> /etc/fstab
    sudo echo "/dev/md0p4 /raid/part4    defaults 0 0" >> /etc/fstab
    sudo echo "/dev/md0p5 /raid/part5    defaults 0 0" >> /etc/fstab
    sudo echo "/dev/md0p6 /raid/part6    defaults 0 0" >> /etc/fstab

raid6 builds on boot

2 RAID check, simulation of disk failure

fail block device /dev/sde

mdadm /dev/md0 --fail /dev/sde
>mdadm: set /dev/sde faulty in /dev/md0

Check the status of Raid, [UUU_UU] space indicates drive fail

   cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4] 
md0 : active raid6 sdg[5] sdf[4] sde[3](F) sdd[2] sdc[1] sdb[0]
1015808 blocks super 1.2 level 6, 512k chunk, algorithm 2 [6/5] [UUU_UU]

Check detail:

mdadm -D /dev/md0
Number   Major   Minor   RaidDevice State
0       8       16        0      active sync   /dev/sdb
1       8       32        1      active sync   /dev/sdc
2       8       48        2      active sync   /dev/sdd
-       0        0        3      removed
4       8       80        4      active sync   /dev/sdf
5       8       96        5      active sync   /dev/sdg
3       8       64        -      faulty   /dev/sde

Delete the broken disk mdadm /dev/md0 --remove /dev/sde mdadm: hot removed /dev/sde from /dev/md0

add the replaced disk to the RAID mdadm /dev/md0 --add /dev/sde mdadm: added /dev/sde

Check RAID status, no spaces [UUUUUU] - disks in working condition cat /proc/mdstat

Personalities : [raid6] [raid5] [raid4] 
md0 : active raid6 sde[6] sdg[5] sdf[4] sdd[2] sdc[1] sdb[0]
1015808 blocks super 1.2 level 6, 512k chunk, algorithm 2 [6/6] [UUUUUU]