我怎样才能安全地关闭软件 RAID 1 并确保系统只使用其中一个驱动器，比如说sda。
以下是一些信息：
df -h
Filesystem Size Used Avail Use% Mounted on
udev 7.8G 0 7.8G 0% /dev
tmpfs 1.6G 1.3M 1.6G 1% /run
/dev/md127p1 40G 35G 2.6G 94% /
tmpfs 7.9G 4.0K 7.9G 1% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
tmpfs 7.9G 0 7.9G 0% /sys/fs/cgroup
/dev/md0p1 49G 8.5G 38G 19% /var
tmpfs 1.6G 0 1.6G 0% /run/user/1000
输出cat /etc/fstab：
$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
/dev/disk/by-uuid/9e905102-9a35-4d74-a181-513e2c8bb342 none swap sw 0 0
/dev/disk/by-uuid/9ed2eb9e-70d2-4fa1-b18b-cccb809327f2 none swap sw 0 0
# / was on /dev/md127p1 during curtin installation
/dev/disk/by-id/md-uuid-8cebc92a:c7b2af7b:ddd9d611:631a5229-part1 / ext4 defaults 0 0
# /var was on /dev/md0p1 during curtin installation
/dev/disk/by-id/md-uuid-81bb4e36:54a0a6db:b1f2250e:bdf5f3d9-part1 /var ext4 defaults 0 0
/swap.img none swap sw 0 0
以下是更多信息：
sudo mdadm --detail /dev/md0
/dev/md0:
Version : 1.2
Creation Time : Wed Dec 9 10:23:16 2020
Raid Level : raid1
Array Size : 52391936 (49.96 GiB 53.65 GB)
Used Dev Size : 52391936 (49.96 GiB 53.65 GB)
Raid Devices : 2
Total Devices : 2
Persistence : Superblock is persistent
Update Time : Wed Nov 22 19:40:25 2023
State : active
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Consistency Policy : resync
Name : ubuntu-server:0
UUID : 81bb4e36:54a0a6db:b1f2250e:bdf5f3d9
Events : 9618
Number Major Minor RaidDevice State
2 8 19 0 active sync /dev/sdb3
1 8 2 1 active sync /dev/sda2
据我所知，/dev/sdb3 和 /dev/sda2 之间有软件 RAID1。
我的问题是如何才能完全关闭它并仅使用 /dev/sda2 来启动和运行系统？