# mount -a命令的基本作用
# 挂载/etc/fstab中所有未挂载的文件系统
# mount -a

# 查看mount命令的帮助
# mount –help

# -a, –all mount all filesystems mentioned in fstab

# 基本用法
# mount -a

# 详细输出
# mount -av
mount: UUID=12345678-90ab-cdef-1234-567890abcdef mounted on /boot.
mount: /dev/mapper/rhel-root mounted on /.
mount: /dev/mapper/rhel-swap mounted on /dev/shm.
mount: /dev/vdb1 mounted on /data/xfs.
mount: /dev/vdb2 mounted on /data/ext4.

# 模拟挂载（不实际执行）
# mount -af

# 验证/etc/fstab配置

# 1. 查看/etc/fstab文件
# cat /etc/fstab

# /etc/fstab
# Created by anaconda on Thu Mar 31 10:00:00 2026
#
# Accessible filesystems, by reference, are maintained under ‘/dev/disk/’
# See man pages fstab(5), findfs(8), mount(8) and/or blkid(8) for more info
#
/dev/mapper/rhel-root / xfs defaults 0 0
UUID=12345678-90ab-cdef-1234-567890abcdef /boot xfs defaults 0 0
/dev/mapper/rhel-swap swap swap defaults 0 0
UUID=45678901-23ab-cdef-4567-890abcdef123 /data/xfs xfs defaults 0 0
UUID=56789012-34ab-cdef-5678-90abcdef234 /data/ext4 ext4 defaults 0 0

# 2. 测试挂载
# mount -a

# 3. 查看挂载结果
# mount | grep /data
/dev/vdb1 on /data/xfs type xfs (rw,relatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota)
/dev/vdb2 on /data/ext4 type ext4 (rw,relatime,seclabel)

# 4. 查看磁盘使用情况
# df -h /data/xfs /data/ext4
Filesystem Size Used Avail Use% Mounted on
/dev/vdb1 50G 33M 50G 1% /data/xfs
/dev/vdb2 50G 61M 47G 1% /data/ext4

# 常见错误及解决方法

# 1. 设备不存在
# 错误信息：mount: /data/xfs: special device UUID=invalid-uuid does not exist.
# 解决方法：
# 检查设备UUID
# blkid /dev/vdb1
# 更新/etc/fstab文件中的UUID

# 2. 挂载点不存在
# 错误信息：mount: /data/xfs: mount point does not exist.
# 解决方法：
# 创建挂载点
# mkdir -p /data/xfs

# 3. 文件系统类型错误
# 错误信息：mount: /dev/vdb1: wrong fs type, bad option, bad superblock on /dev/vdb1, missing codepage or helper
program, or other error.
# 解决方法：
# 检查文件系统类型
# blkid /dev/vdb1
# 更新/etc/fstab文件中的文件系统类型

# 4. 挂载选项错误
# 错误信息：mount: /data/xfs: unknown mount option.
# 解决方法：
# 检查挂载选项
# 更新/etc/fstab文件中的挂载选项

# 5. 设备已被挂载
# 错误信息：mount: /dev/vdb1: /data/xfs already mounted or mount point busy.
# 解决方法：
# 查看挂载状态
# mount | grep /data/xfs
# 如果已挂载，无需处理；如果未挂载，检查挂载点是否被占用

# 场景：配置并验证多个文件系统的永久挂载

# 1. 查看设备信息
# lsblk -f
NAME FSTYPE LABEL UUID MOUNTPOINT
vda
├─vda1 xfs 12345678-90ab-cdef-1234-567890abcdef /boot
└─vda2 LVM2_member 87654321-0987-fedc-ba98-76543210fedc
├─rhel-root xfs 23456789-0abc-def1-2345-67890abcdef1 /
└─rhel-swap swap 34567890-12ab-cdef-3456-7890abcdef2 [SWAP]
vdb
├─vdb1 xfs 45678901-23ab-cdef-4567-890abcdef123
├─vdb2 ext4 56789012-34ab-cdef-5678-90abcdef234
└─vdb3 xfs 67890123-45ab-cdef-6789-0abcdef3456

# 2. 创建挂载点
# mkdir -p /data/xfs /data/ext4 /data/backup

# 3. 编辑/etc/fstab文件
# cat >> /etc/fstab << 'EOF' # 数据分区 UUID=45678901-23ab-cdef-4567-890abcdef123 /data/xfs xfs defaults,noatime 0 0 UUID=56789012-34ab-cdef-5678-90abcdef234 /data/ext4 ext4 defaults,noatime 0 0 UUID=67890123-45ab-cdef-6789-0abcdef3456 /data/backup xfs defaults,noatime 0 0 EOF # 4. 验证/etc/fstab配置 # mount -a # 5. 检查是否有错误 # echo $? 0 # 6. 查看挂载结果 # mount | grep /data /dev/vdb1 on /data/xfs type xfs (rw,noatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) /dev/vdb2 on /data/ext4 type ext4 (rw,noatime,seclabel) /dev/vdb3 on /data/backup type xfs (rw,noatime,seclabel,attr2,inode64,logbufs=8,logbsize=32k,noquota) # 7. 查看磁盘使用情况 # df -h Filesystem Size Used Avail Use% Mounted on devtmpfs 3.8G 0 3.8G 0% /dev tmpfs 3.9G 0 3.9G 0% /dev/shm tmpfs 3.9G 9.0M 3.8G 1% /run tmpfs 3.9G 0 3.9G 0% /sys/fs/cgroup /dev/mapper/rhel-root 45G 3.5G 42G 8% / /dev/vda1 1014M 194M 821M 20% /boot tmpfs 781M 0 781M 0% /run/user/0 /dev/vdb1 50G 33M 50G 1% /data/xfs /dev/vdb2 50G 61M 47G 1% /data/ext4 /dev/vdb3 50G 33M 50G 1% /data/backup # 8. 测试写入数据 # echo "Test data">
/data/xfs/test.txt
# echo “Test data” > /data/ext4/test.txt
# echo “Test data” > /data/backup/test.txt

# 9. 验证数据
# ls -la /data/xfs /data/ext4 /data/backup
/data/xfs:
total 4
drwxr-xr-x. 2 root root 20 Mar 31 10:00 .
drwxr-xr-x. 5 root root 40 Mar 31 10:00 ..
-rw-r–r–. 1 root root 10 Mar 31 10:00 test.txt

/data/ext4:
total 24
drwxr-xr-x. 3 root root 4096 Mar 31 10:00 .
drwxr-xr-x. 5 root root 40 Mar 31 10:00 ..
drwx——. 2 root root 16384 Mar 31 10:00 lost+found
-rw-r–r–. 1 root root 10 Mar 31 10:00 test.txt

/data/backup:
total 4
drwxr-xr-x. 2 root root 20 Mar 31 10:00 .
drwxr-xr-x. 5 root root 40 Mar 31 10:00 ..
-rw-r–r–. 1 root root 10 Mar 31 10:00 test.txt