我错误地想添加一个分区/dev/sda，我用 fdisk 启动/dev/sda2它并将其视为磁盘。我该如何恢复它？
ghostrider@dev1:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 800G 0 disk
├─sda1 8:1 0 953M 0 part /boot
└─sda2 8:2 0 399.1G 0 part /
ghostrider@dev1:~$ sudo fdisk /dev/sda2
Welcome to fdisk (util-linux 2.34).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
The old ext4 signature will be removed by a write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x1d9559e3.
Command (m for help): p
Disk /dev/sda2: 399.7 GiB, 428495339520 bytes, 836904960 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: dos
Disk identifier: 0x1d9559e3
Command (m for help): F
Unpartitioned space /dev/sda2: 399.7 GiB, 428494290944 bytes, 836902912 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
Start End Sectors Size
2048 836904959 836902912 399.1G
Command (m for help): n
Partition type
p primary (0 primary, 0 extended, 4 free)
e extended (container for logical partitions)
Select (default p): p
Partition number (1-4, default 1):
First sector (2048-836904959, default 2048):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (2048-836904959, default 836904959):
Created a new partition 1 of type 'Linux' and of size 399.1 GiB.
Command (m for help): w
The partition table has been altered.
Failed to add partition 1 to system: Invalid argument
The kernel still uses the old partitions. The new table will be used at the next reboot.
Syncing disks.
ghostrider@dev1:~$ lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 800G 0 disk
├─sda1 8:1 0 953M 0 part /boot
└─sda2 8:2 0 399.1G 0 part /
编辑： 稍后服务器重启后，服务器卡在 initramfs 中并显示错误消息
Gave up waiting for root
ALERT! UUID=xx-xx-xx-xx-xx doesn't exist dropping to shell
答案1
看起来什么都没发生，因为fdisk无法覆盖文件系统。尝试覆盖时，它显示错误：
Failed to add partition 1 to system: Invalid argument
不过，这是确保您的备份是最新且可恢复的好时机。无论如何，可能确实出了问题。
请注意，在您执行任何操作之前，它fdisk确实会尝试警告您有关该问题。它警告：
The old ext4 signature will be removed by a write command.
Device does not contain a recognized partition table.
Created a new DOS disklabel with disk identifier 0x1d9559e3.
即使你对工具打印的消息非常熟悉，也最好通读一遍，因为有一天可能会出现意想不到的事情。如果你注意到了这一点，你可能会在造成任何损害之前意识到出了问题。