具体如下
root@ubuntu:~# fdisk /dev/sda
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.
#查询现有分区情况，40G需要扩展到50G
Command (m for help): p
Disk /dev/sda: 50 GiB, 53687091200 bytes, 104857600 sectors
Disk model: VMware Virtual S
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: 0xa52b58b2
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 1050623 1048576 512M b W95 FAT32
/dev/sda2 1052670 83886079 82833410 39.5G 5 Extended
/dev/sda5 1052672 83886079 82833408 39.5G 83 Linux
#删除sda5分区
Command (m for help): d
Partition number (1,2,5, default 5): 5
Partition 5 has been deleted.
#删除sda2分区
Command (m for help): d
Partition number (1,2, default 2): 2
Partition 2 has been deleted.
# 创建新扩展分区sda2（不断的按默认回车）
Command (m for help): n
Partition type
p primary (1 primary, 0 extended, 3 free)
e extended (container for logical partitions)
Select (default p): e （选择扩展分区）
Partition number (2-4, default 2):
First sector (1050624-104857599, default 1050624):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (1050624-104857599, default 104857599): +49.5G
Value out of range.
Last sector, +/-sectors or +/-size{K,M,G,T,P} (1050624-104857599, default 104857599):
Created a new partition 2 of type 'Extended' and of size 49.5 GiB.
#查询创建好的扩展分区
Command (m for help): p
Disk /dev/sda: 50 GiB, 53687091200 bytes, 104857600 sectors
Disk model: VMware Virtual S
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: 0xa52b58b2
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 1050623 1048576 512M b W95 FAT32
/dev/sda2 1050624 104857599 103806976 49.5G 5 Extended
# 继续创建分区，默认主分区这个时候就是在扩展分区下面
Command (m for help): n
All space for primary partitions is in use.
Adding logical partition 5
First sector (1052672-104857599, default 1052672):
Last sector, +/-sectors or +/-size{K,M,G,T,P} (1052672-104857599, default 104857599):
Created a new partition 5 of type 'Linux' and of size 49.5 GiB.
Partition #5 contains a ext4 signature.
Do you want to remove the signature? [Y]es/[N]o: Y
The signature will be removed by a write command.
# 查询创建好的分区，这个时候所有的空间都已经用了
Command (m for help): p
Disk /dev/sda: 50 GiB, 53687091200 bytes, 104857600 sectors
Disk model: VMware Virtual S
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: 0xa52b58b2
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 1050623 1048576 512M b W95 FAT32
/dev/sda2 1050624 104857599 103806976 49.5G 5 Extended
/dev/sda5 1052672 104857599 103804928 49.5G 83 Linux
Filesystem/RAID signature on partition 5 will be wiped.
# 保存退出，因为我们是根分区，所以会提示分区忙碌
Command (m for help): w
The partition table has been altered.
Failed to add partition 2 to system: Device or resource busy
The kernel still uses the old partitions. The new table will be used at the next reboot.
Syncing disks.
重启服务器
init 6
重启后查看分区情况
发现还是没有生效，但是分区却已经扩展了
root@ubuntu:~# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda5 39G 7.4G 30G 20% /
/dev/sda1 511M 4.0K 511M 1% /boot/efi
root@ubuntu:~# lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 50G 0 disk
├─sda1 8:1 0 512M 0 part /boot/efi
├─sda2 8:2 0 1K 0 part
└─sda5 8:5 0 49.5G 0 part /
刷新盘符
root@ubuntu:~# resize2fs /dev/sda5
resize2fs 1.45.5 (07-Jan-2020)
Filesystem at /dev/sda5 is mounted on /; on-line resizing required
old_desc_blocks = 5, new_desc_blocks = 7
The filesystem on /dev/sda5 is now 12975616 (4k) blocks long.
root@ubuntu:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 1.9G 0 1.9G 0% /dev
/dev/sda5 49G 7.4G 40G 16% /
/dev/sda1 511M 4.0K 511M 1% /boot/efi
最后重启一次服务器验证是否有问题