RAID 10
[root@linuxprobe ~]# mdadm -Cv /dev/md0 -a yes -n 4 -l 10 /dev/sdb /dev/sdc /dev/sdd /dev/sde mdadm: layout defaults to n2 mdadm: layout defaults to n2 mdadm: chunk size defaults to 512K mdadm: size set to 20954624K mdadm: Defaulting to version 1.2 metadata mdadm: array /dev/md0 started.
[root@linuxprobe ~]# mkfs.ext4 /dev/md0 mke2fs 1.42.9 (28-Dec-2013) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=128 blocks, Stripe width=256 blocks 2621440 inodes, 10477312 blocks 523865 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=2157969408 320 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624 Allocating group tables: done Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done
[root@linuxprobe ~]# mkdir /RAID10 [root@linuxprobe ~]# mount /dev/md0 /RAID10 [root@linuxprobe ~]# df -h Filesystem Size Used Avail Use% Mounted on /dev/mapper/centos-root 18G 3.5G 15G 20% / devtmpfs 905M 0 905M 0% /dev tmpfs 914M 140K 914M 1% /dev/shm tmpfs 914M 8.8M 905M 1% /run tmpfs 914M 0 914M 0% /sys/fs/cgroup /dev/sr0 6.6G 6.6G 0 100% /media/cdrom /dev/sda1 497M 119M 379M 24% /boot /dev/md0 40G 49M 38G 1% /RAID10
[root@linuxprobe ~]# mdadm -D /dev/md0 /dev/md0: Version : 1.2 Creation Time : Thu Jan 16 19:30:24 2020 Raid Level : raid10 Array Size : 41909248 (39.97 GiB 42.92 GB) Used Dev Size : 20954624 (19.98 GiB 21.46 GB) Raid Devices : 4 Total Devices : 4 Persistence : Superblock is persistent Update Time : Thu Jan 16 19:48:47 2020 State : clean Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : near=2 Chunk Size : 512K Name : linuxprobe:0 (local to host linuxprobe) UUID : 3c045189:f5f903db:5728adf6:fa3baac1 Events : 19 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 3 8 64 3 active sync /dev/sde
[root@linuxprobe ~]# mdadm /dev/md0 -f /dev/sdb mdadm: set /dev/sdb faulty in /dev/md0 [root@linuxprobe ~]# mdadm -D /dev/md0 /dev/md0: Version : 1.2 Creation Time : Thu Jan 16 19:30:24 2020 Raid Level : raid10 Array Size : 41909248 (39.97 GiB 42.92 GB) Used Dev Size : 20954624 (19.98 GiB 21.46 GB) Raid Devices : 4 Total Devices : 4 Persistence : Superblock is persistent Update Time : Thu Jan 16 19:52:27 2020 State : clean, degraded Active Devices : 3 Working Devices : 3 Failed Devices : 1 Spare Devices : 0 Layout : near=2 Chunk Size : 512K Name : linuxprobe:0 (local to host linuxprobe) UUID : 3c045189:f5f903db:5728adf6:fa3baac1 Events : 99 Number Major Minor RaidDevice State 0 0 0 0 removed 1 8 32 1 active sync /dev/sdc 2 8 48 2 active sync /dev/sdd 3 8 64 3 active sync /dev/sde 0 8 16 - faulty /dev/sdb
[root@linuxprobe ~]# mdadm /dev/md0 -a /dev/sdb mdadm: Cannot open /dev/sdb: Device or resource busy [root@linuxprobe ~]# mdadm /dev/md0 -a /dev/sdf mdadm: added /dev/sdf [root@linuxprobe ~]# mdadm -D /dev/md0 /dev/md0: Version : 1.2 Creation Time : Thu Jan 16 19:30:24 2020 Raid Level : raid10 Array Size : 41909248 (39.97 GiB 42.92 GB) Used Dev Size : 20954624 (19.98 GiB 21.46 GB) Raid Devices : 4 Total Devices : 4 Persistence : Superblock is persistent Update Time : Thu Jan 16 20:03:18 2020 State : clean Active Devices : 4 Working Devices : 4 Failed Devices : 0 Spare Devices : 0 Layout : near=2 Chunk Size : 512K Name : linuxprobe:0 (local to host linuxprobe) UUID : 3c045189:f5f903db:5728adf6:fa3baac1 Events : 339 Number Major Minor RaidDevice State 4 8 80 0 active sync /dev/sdf 1 8 32 1 active sync /dev/sdc 2 8 48 2 active sync /dev/sdd 3 8 64 3 active sync /dev/sde