群晖raid1改为basic

将两盘raid1(SHR)改为basic。

• 拔掉raid1中的一个硬盘；
• cat /proc/mdstat查看当前阵列状态；
• md0/md1一般是群晖的系统分区，从md2开始确认硬盘对应的分区；
• mdadm --grow --raid-devices=1 --force /dev/md2
• 在存储空间管理中确认已变为basic.

root@NAS:~# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md2 : active raid1 sda3[2]
      2925423616 blocks super 1.2 [2/1] [_U]

md3 : active raid1 sdd3[0]
      2925444544 blocks super 1.2 [1/1] [U]

md4 : active raid1 sdb3[0]
      3902196544 blocks super 1.2 [1/1] [U]

md5 : active raid1 sdf3[0]
      483564544 blocks super 1.2 [1/1] [U]

md6 : active raid1 sdc3[0]
      2925444544 blocks super 1.2 [1/1] [U]

md1 : active raid1 sda2[0] sdb2[1] sdc2[2] sdd2[3] sdf2[4]
      2097088 blocks [16/5] [UUUUU___________]

md0 : active raid1 sda1[0] sdb1[1] sdc1[2] sdd1[3] sdf1[4]
      2490176 blocks [12/5] [UUUUU_______]

unused devices: <none>
root@NAS:~# mdadm --grow --raid-devices=1 --force /dev/md2
raid_disks for /dev/md2 set to 1
root@NAS:~# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md2 : active raid1 sda3[2]
      2925423616 blocks super 1.2 [1/1] [U]

md3 : active raid1 sdd3[0]
      2925444544 blocks super 1.2 [1/1] [U]

md4 : active raid1 sdb3[0]
      3902196544 blocks super 1.2 [1/1] [U]

md5 : active raid1 sdf3[0]
      483564544 blocks super 1.2 [1/1] [U]

md6 : active raid1 sdc3[0]
      2925444544 blocks super 1.2 [1/1] [U]

md1 : active raid1 sda2[0] sdb2[1] sdc2[2] sdd2[3] sdf2[4]
      2097088 blocks [16/5] [UUUUU___________]

md0 : active raid1 sda1[0] sdb1[1] sdc1[2] sdd1[3] sdf1[4]
      2490176 blocks [12/5] [UUUUU_______]

unused devices: <none>