一 、挂载新磁盘
查看磁盘
[root@localhost ~]# fdisk -l
Disk /dev/vda: 53.7 GB, 53687091200 bytes, 104857600 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
Disk label type: dos
Disk identifier: 0x000c81ed
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 104857566 52427759+ 83 Linux
Disk /dev/vdb: 2199.0 GB, 2199023255552 bytes, 4294967296 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
磁盘/dev/vdb尚有2199GB未分配
查看分区
df -Th 或者lsblk
[root@localhost ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs tmpfs 7.8G 488K 7.8G 1% /run
tmpfs tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup
/dev/vda1 ext4 50G 2.0G 45G 5% /
tmpfs tmpfs 1.6G 0 1.6G 0% /run/user/0
磁盘/dev/vdb实际并没有挂载
磁盘分区
注意：
# 执行"fdisk /dev/vdb"后，出现"Command (m for help)"提示时，依次输入下面指令
n -> p -> 1 -> 回车 -> 回车 -> w
详情：
[root@localhost ~]# fdisk /dev/vdb
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 0x11e106cf.
WARNING: The size of this disk is 2.2 TB (2199023255552 bytes).
DOS partition table format can not be used on drives for volumes
larger than (2199023255040 bytes) for 512-byte sectors. Use parted(1) and GUID
partition table format (GPT).
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p): p
Partition number (1-4, default 1): 1
First sector (2048-4294967295, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-4294967294, default 4294967294):
Using default value 4294967294
Partition 1 of type Linux and of size 2 TiB is set
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
说明：
n：添加新分区
p：设为主分区
1: 分区序号
两个回车指是开始和结束的磁盘大小；
w：写入磁盘
tips: 可以使用partprobe命令刷新分区信息
格式分区
[root@localhost ~]# mkfs.ext4 /dev/vdb1
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
134217728 inodes, 536870655 blocks
26843532 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2684354560
16384 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872, 71663616, 78675968,
102400000, 214990848, 512000000
Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done
挂载磁盘
mkdir /mnt
mount /dev/vdb1 /mnt
确认磁盘
[root@localhost ~]# fdisk -l
Disk /dev/vda: 53.7 GB, 53687091200 bytes, 104857600 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
Disk label type: dos
Disk identifier: 0x000c81ed
Device Boot Start End Blocks Id System
/dev/vda1 * 2048 104857566 52427759+ 83 Linux
Disk /dev/vdb: 2199.0 GB, 2199023255552 bytes, 4294967296 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
Disk label type: dos
Disk identifier: 0x11e106cf
Device Boot Start End Blocks Id System
/dev/vdb1 2048 4294967294 2147482623+ 83 Linux
确认分区
[root@localhost ~]# df -Th
Filesystem Type Size Used Avail Use% Mounted on
devtmpfs devtmpfs 7.8G 0 7.8G 0% /dev
tmpfs tmpfs 7.8G 0 7.8G 0% /dev/shm
tmpfs tmpfs 7.8G 492K 7.8G 1% /run
tmpfs tmpfs 7.8G 0 7.8G 0% /sys/fs/cgroup
/dev/vda1 ext4 50G 2.0G 45G 5% /
tmpfs tmpfs 1.6G 0 1.6G 0% /run/user/0
/dev/vdb1 ext4 2.0T 81M 1.9T 1% /mnt
开机启动
echo "/dev/vdb1 /mnt ext4 defaults 0 0" >> /etc/fstab
二 、挂载旧目录
如果你要用来挂载的目录里面并不是空的，那么挂载了文件系统之后，原目录下的东西就会暂时的消失。并不是被覆盖掉，而是暂时的隐藏了起来，等到新分割槽被卸除之后，则原目录原本的内容就会再次出来。
如果要永久挂载已有目录，可以在新硬盘创建文件系统后，先挂载到一个临时目录，然后把要扩展的目录复制到这临时目录，然后删除要扩展的目录，再卸载临时挂载点，重新挂载到要扩展的目录上。举例：
# 比如要扩充 /var
# 在创建好文件系统后 新建临时挂载点 mnt
mkdir /mnt
# 将/dev/sdb1挂载到/mnt下
mount /dev/vdb1 /mnt
# 拷贝/var下的所有内容到新的硬盘
cp -pdr /var/* /mnt
# 删除当前/var目录下的内容
rm -rf /var/*
# 卸载磁盘
umount /dev/vdb1
# 重新挂载磁盘到/var目录
mount /dev/vdb1 /var
# 过程中若提示磁盘忙，使用fuser找出将正在使用磁盘的程序并结束掉；
fuser -m -v /var
fuser -m -v -i -k /var
# 开机启动
echo "/dev/vdb1 /var ext4 defaults 0 0" >> /etc/fstab