bash
login as: root
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│ ⮞ SSH session to root@192.168.75.102 │
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Last login: Fri Jan 16 23:53:00 2026 from 192.168.75.1
[root@rac2 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdd 8:48 0 10G 0 disk
└─sdd1 8:49 0 10G 0 part
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
sr0 11:0 1 4.3G 0 rom
sdc 8:32 0 10G 0 disk
└─sdc1 8:33 0 10G 0 part
sda 8:0 0 32G 0 disk
├─sda2 8:2 0 24G 0 part
│ ├─ol-swap 252:1 0 2.5G 0 lvm [SWAP]
│ └─ol-root 252:0 0 21.5G 0 lvm /
└─sda1 8:1 0 1G 0 part /boot
[root@rac2 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdd 8:48 0 10G 0 disk
└─sdd1 8:49 0 10G 0 part
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
sr0 11:0 1 4.3G 0 rom
sdc 8:32 0 10G 0 disk
└─sdc1 8:33 0 10G 0 part
sda 8:0 0 32G 0 disk
├─sda2 8:2 0 24G 0 part
│ ├─ol-swap 252:1 0 2.5G 0 lvm [SWAP]
│ └─ol-root 252:0 0 21.5G 0 lvm /
└─sda1 8:1 0 1G 0 part /boot
[root@rac2 ~]# fdisk /dev/sda2
Welcome to fdisk (util-linux 2.23.2).
Changes will remain in memory only, until you decide to write them.
Be careful before using the write command.
Device does not contain a recognized partition table
Building a new DOS disklabel with disk identifier 0xb89de9ce.
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): ^Z
[1]+ Stopped fdisk /dev/sda2
[root@rac2 ~]# gdisk /dev/sda
GPT fdisk (gdisk) version 0.8.10
Partition table scan:
MBR: MBR only
BSD: not present
APM: not present
GPT: not present
***************************************************************
Found invalid GPT and valid MBR; converting MBR to GPT format
in memory. THIS OPERATION IS POTENTIALLY DESTRUCTIVE! Exit by
typing 'q' if you don't want to convert your MBR partitions
to GPT format!
***************************************************************
Command (? for help): m
b back up GPT data to a file
c change a partition's name
d delete a partition
i show detailed information on a partition
l list known partition types
n add a new partition
o create a new empty GUID partition table (GPT)
p print the partition table
q quit without saving changes
r recovery and transformation options (experts only)
s sort partitions
t change a partition's type code
v verify disk
w write table to disk and exit
x extra functionality (experts only)
? print this menu
Command (? for help): n
Partition number (3-128, default 3):
First sector (34-67108830, default = 52428800) or {+-}size{KMGTP}:
Last sector (52428800-67108830, default = 67108830) or {+-}size{KMGTP}:
Current type is 'Linux filesystem'
Hex code or GUID (L to show codes, Enter = 8300):
Changed type of partition to 'Linux filesystem'
Command (? for help): w
Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING
PARTITIONS!!
Do you want to proceed? (Y/N): y
OK; writing new GUID partition table (GPT) to /dev/sda.
Warning: The kernel is still using the old partition table.
The new table will be used at the next reboot.
The operation has completed successfully.
[root@rac2 ~]# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sdd 8:48 0 10G 0 disk
└─sdd1 8:49 0 10G 0 part
sdb 8:16 0 10G 0 disk
└─sdb1 8:17 0 10G 0 part
sr0 11:0 1 4.3G 0 rom
sdc 8:32 0 10G 0 disk
└─sdc1 8:33 0 10G 0 part
sda 8:0 0 32G 0 disk
├─sda2 8:2 0 24G 0 part
│ ├─ol-swap 252:1 0 2.5G 0 lvm [SWAP]
│ └─ol-root 252:0 0 21.5G 0 lvm /
└─sda1 8:1 0 1G 0 part /boot
[root@rac2 ~]# reboot
Remote side unexpectedly closed network connection
──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Session stopped
- Press <Return> to exit tab
- Press R to restart session
- Press S to save terminal output to file
Network error: Connection timed out
──────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────────
Session stopped
- Press <Return> to exit tab
- Press R to restart session
- Press S to save terminal output to file以上我们最开始有一个fdisk由变成gdisk的操作，这会将原MBR磁盘转换为GPT分区表，但MBR和GPT是不兼容的分区表格式。此时接入操作系统大屏，会发现大屏为黑屏，这是因为操作系统无法从GPT磁盘启动，而原来的MBR引导信息被破坏了。
这个时候情况比较严重了，通常只能说重装系统了，所以在操作之前一定务必谨慎又谨慎。