在windows操作系统中，硬盘有fat32和ntfs等多种格式。在linux中同样如此。CentOS 6之前，主要是ext4、ext3和ext2等格式。在CentOS 7这个版本开始，默认的磁盘格式变成了xfs格式。
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[root@server02 ~]
# cat /etc/filesystems
xfs
ext4
ext3
ext2
nodev proc
nodev devpts
iso9660
vfat
hfs
hfsplus
*
[root@server02 ~]
# mount //查看分区的文件系统类型，需要挂载才能看见
sysfs on
/sys
type
sysfs (rw,nosuid,nodev,noexec,relatime,seclabel)
proc on
/proc
type
proc (rw,nosuid,nodev,noexec,relatime)
devtmpfs on
/dev
type
devtmpfs (rw,nosuid,seclabel,size=494380k,nr_inodes=123595,mode=755)
securityfs on
/sys/kernel/security
type
securityfs (rw,nosuid,nodev,noexec,relatime)
tmpfs on
/dev/shm
type
tmpfs (rw,nosuid,nodev,seclabel)
devpts on
/dev/pts
type
devpts (rw,nosuid,noexec,relatime,seclabel,gid=5,mode=620,ptmxmode=000)
tmpfs on
/run
type
tmpfs (rw,nosuid,nodev,seclabel,mode=755)
tmpfs on
/sys/fs/cgroup
type
tmpfs (ro,nosuid,nodev,noexec,seclabel,mode=755)
cgroup on
/sys/fs/cgroup/systemd
type
cgroup (rw,nosuid,nodev,noexec,relatime,xattr,release_agent=
/usr/lib/systemd/systemd-cgroups-agent
,name=systemd)
pstore on
/sys/fs/pstore
type
pstore (rw,nosuid,nodev,noexec,relatime)
cgroup on
/sys/fs/cgroup/freezer
type
cgroup (rw,nosuid,nodev,noexec,relatime,freezer)
cgroup on
/sys/fs/cgroup/cpu
,cpuacct
type
cgroup (rw,nosuid,nodev,noexec,relatime,cpuacct,cpu)
cgroup on
/sys/fs/cgroup/pids
type
cgroup (rw,nosuid,nodev,noexec,relatime,pids)
cgroup on
/sys/fs/cgroup/cpuset
type
cgroup (rw,nosuid,nodev,noexec,relatime,cpuset)
cgroup on
/sys/fs/cgroup/net_cls
,net_prio
type
cgroup (rw,nosuid,nodev,noexec,relatime,net_prio,net_cls)
cgroup on
/sys/fs/cgroup/memory
type
cgroup (rw,nosuid,nodev,noexec,relatime,memory)
cgroup on
/sys/fs/cgroup/perf_event
type
cgroup (rw,nosuid,nodev,noexec,relatime,perf_event)
cgroup on
/sys/fs/cgroup/devices
type
cgroup (rw,nosuid,nodev,noexec,relatime,devices)
cgroup on
/sys/fs/cgroup/hugetlb
type
cgroup (rw,nosuid,nodev,noexec,relatime,hugetlb)
cgroup on
/sys/fs/cgroup/blkio
type
cgroup (rw,nosuid,nodev,noexec,relatime,blkio)
configfs on
/sys/kernel/config
type
configfs (rw,relatime)
/dev/sda3
on /
type
xfs (rw,relatime,seclabel,attr2,inode64,noquota)
selinuxfs on
/sys/fs/selinux
type
selinuxfs (rw,relatime)
systemd-1 on
/proc/sys/fs/binfmt_misc
type
autofs (rw,relatime,fd=26,pgrp=1,timeout=300,minproto=5,maxproto=5,direct)
debugfs on
/sys/kernel/debug
type
debugfs (rw,relatime)
hugetlbfs on
/dev/hugepages
type
hugetlbfs (rw,relatime,seclabel)
mqueue on
/dev/mqueue
type
mqueue (rw,relatime,seclabel)
/dev/sda1
on
/boot
type
xfs (rw,relatime,seclabel,attr2,inode64,noquota)
tmpfs on
/run/user/0
type
tmpfs (rw,nosuid,nodev,relatime,seclabel,size=100840k,mode=700)
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一、磁盘格式化
| 命令 | 参数 | 涵义 |
| mke2fs |
-t | 指定格式，不支持xfs； mkfs.ext4 = mke2fs -t ext4 |
| -b | 指定块大小 | |
| -m | 指定预留空间比（默认5%预留给超级用户） | |
| -i | 指定每组的inode数，默认4个块对应1个inode | |
| mkfs.xfs | 格式化成xfs |
测试示例：
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[root@server02 ~]
# mke2fs -t xfs /dev/sdb2
mke2fs 1.42.9 (28-Dec-2013)
Your mke2fs.conf
file
does not define the xfs filesystem
type
.
Aborting...
[root@server02 ~]
# mkfs.xfs /dev/sdb2
meta-data=
/dev/sdb2
isize=512 agcount=4, agsize=131072 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=524288, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=2560, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
[root@server02 ~]
# blkid /dev/sdb2
/dev/sdb2
: UUID=
"d1873a00-ba11-4635-81af-a1e9bd697f70"
TYPE=
"xfs"
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二、磁盘挂载
只有格式化的分区才能被挂载。挂载使用mount命令，卸载使用umount命令。使用“-o”可以跟各种选项。默认选项为rw,suid,dev,exec,auto,nouser,和async。
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[root@server02 ~]
# mount /dev/sdb2 /mnt/
[root@server02 ~]
# mount /dev/sdb3 /mnt/
mount
:
/dev/sdb3
写保护，将以只读方式挂载
mount
: 未知的文件系统类型“(null)”
[root@server02 ~]
# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3
28G 1016M 27G 4% /
devtmpfs 483M 0 483M 0%
/dev
tmpfs 493M 0 493M 0%
/dev/shm
tmpfs 493M 6.8M 486M 2%
/run
tmpfs 493M 0 493M 0%
/sys/fs/cgroup
/dev/sda1
197M 109M 88M 56%
/boot
tmpfs 99M 0 99M 0%
/run/user/0
/dev/sdb2
2.0G 33M 2.0G 2%
/mnt
[root@server02 ~]
# umount /dev/sdb2
[root@server02 ~]
# df -h
文件系统 容量 已用 可用 已用% 挂载点
/dev/sda3
28G 1016M 27G 4% /
devtmpfs 483M 0 483M 0%
/dev
tmpfs 493M 0 493M 0%
/dev/shm
tmpfs 493M 6.8M 486M 2%
/run
tmpfs 493M 0 493M 0%
/sys/fs/cgroup
/dev/sda1
197M 109M 88M 56%
/boot
tmpfs 99M 0 99M 0%
/run/user/0
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通过mount命令挂载的分区只在当前有效，当系统重启之后，分区将会消失。将分区挂载卸载/etc/fstab文件中，可以使系统启动时默认挂载。可以使用mount -a命令自动加载配置文件里的配置。
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[root@server02 ~]
# cat /etc/fstab
#
# /etc/fstab
# Created by anaconda on Sat May 27 06:10:33 2017
#
# 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
#
UUID=de480d95-018b-4e0b-a874-083a13d8412d / xfs defaults 0 0
UUID=82044aec-23c6-4e7f-8f05-51a24c0c956a
/boot
xfs defaults 0 0
UUID=be771427-d6c1-4d01-a8ab-a473e8df8ac5 swap swap defaults 0 0
[root@server02 ~]
# man fstab
......
DESCRIPTION
The
file
fstab contains descriptive information about the various
file
systems. fstab is only
read
by programs, and not written; it is the duty of the system administrator to properly create and maintain this
file
. Each filesystem is described on a separate line; fields on each line are separated by tabs or spaces. Lines starting with
'#'
are comments, blank lines are ignored. The order of records
in
fstab is important because
fsck
(8),
mount
(8), and
umount
(8) sequentially iterate through fstab doing their thing.
The first field (fs_spec).
//UUID
或LABEL
This field describes the block special device or remote filesystem to be mounted.
......
The second field (fs_file).
//
挂载点
This field describes the
mount
point
for
the filesystem. For swap partitions, this field should be specified as `none
'. If the name of the mount point contains spaces these can be escaped as `\040'
.
......
The third field (fs_vfstype).
//
分区格式
This field describes the
type
of the filesystem. Linux supports lots of filesystem types, such as adfs, affs, autofs, coda, coherent, cramfs, devpts, efs, ext2, ext3, hfs,hpfs, iso9660, jfs, minix, msdos, ncpfs, nfs, ntfs, proc, qnx4, reiserfs, romfs, smbfs, sysv, tmpfs, udf, ufs, umsdos, vfat, xenix, xfs, and possibly others. For
more
details, see
mount
(8).
......
The fourth field (fs_mntops).
//
可选选项
This field describes the
mount
options associated with the filesystem.
......
The fifth field (fs_freq).
//
是否备份
This field is used
for
these filesystems by the dump(8)
command
to determine
which
filesystems need to be dumped. If the fifth field is not present, a value of zero is returned and dump will assume that the filesystem does not need to be dumped.
......
The sixth field (fs_passno).
//
是否开机检测，不检查为0，检查为2
This field is used by the
fsck
(8) program to determine the order
in
which
filesystem checks are
done
at reboot
time
. The root filesystem should be specified with a fs_passno of 1, and other filesystems should have a fs_passno of 2. Filesystems within a drive will be checked sequentially, but filesystems on different drives will be checked at the same
time
to utilize parallelism available
in
the hardware. If the sixth field is not present or zero, a value of zero is returned and
fsck
will assume that the filesystem does not need to be checked.
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另外一种开机自动挂载的方法是将mount命令写在/etc/rc.local里，开机自动执行挂载命令达到挂载的效果。
本文转自Grodd51CTO博客，原文链接：http://blog.51cto.com/juispan/1939163
，如需转载请自行联系原作者
