课程：磁盘分区
查看现有硬盘
[root@oldboyedu59 ~]# fdisk -l |grep 'sd[a-z]:'
Disk /dev/sda: 107.4 GB, 107374182400 bytes, 209715200 sectors
Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 sectors
Disk /dev/sdc: 106 MB, 106954752 bytes, 208896 sectors
Disk /dev/sdd: 3221.2 GB, 3221225472000 bytes, 6291456000 sectors
Linux温馨提示（报错）：硬盘分区系列
1.Changes will remain in memory only, until you decide to write them.
你进行的修改默认存放在内存中,直到你决定保存这些修改的时候.
:wq
Be careful before using the write command.
保存之前小心点!
Device does not contain a recognized partition table
设备 没有 包含 磁盘分区表。
Building a new DOS disklabel with disk identifier 0x6df46197.
DPT= disk partition table 磁盘分区表
2.Invalid partition type `e'
无效的分区类型“e”
3.mkfs.xfs /dev/sdb1
mkfs.xfs: /dev/sdb1 appears to contain an existing filesystem (ext4).
这个磁盘分区中 已经包含了1个文件系统（已经格式化过了）
mkfs.xfs: Use the -f option to force overwrite.
如果强制格式化使用-f
4.[root@cuihua ~]# mount /dev/sdb1 /mnt
mount: /dev/sdb1 is write-protected, mounting read-only
mount: unknown filesystem type '(null)'
未知的文件系统（没有格式化）
5.[root@guanggege ~]# mount /dev/sdb1 /mnt/
mount: special device /dev/sdb1 does not exist
特殊文件（设备文件） 不存在
[root@oldboyedu59 ~]# mkfs.xfs /dev/sdb1
mkfs.xfs: /dev/sdb1 contains a mounted filesystem
sdb1磁盘分区 包含 1个已经挂载的文件系统 （磁盘分区已经挂载）
Usage: mkfs.xfs
/* blocksize */ [-b log=n|size=num]
/* metadata */ [-m crc=0|1,finobt=0|1,uuid=xxx]
/* data subvol */ [-d agcount=n,agsize=n,file,name=xxx,size=num,
(sunit=value,swidth=value|su=num,sw=num|noalign),
sectlog=n|sectsize=num
/* force overwrite */ [-f]
/* inode size */ [-i log=n|perblock=n|size=num,maxpct=n,attr=0|1|2,
projid32bit=0|1]
/* no discard */ [-K]
/* log subvol */ [-l agnum=n,internal,size=num,logdev=xxx,version=n
sunit=value|su=num,sectlog=n|sectsize=num,
lazy-count=0|1]
/* label */ [-L label (maximum 12 characters)]
/* naming */ [-n log=n|size=num,version=2|ci,ftype=0|1]
/* no-op info only */ [-N]
/* prototype file */ [-p fname]
/* quiet */ [-q]
/* realtime subvol */ [-r extsize=num,size=num,rtdev=xxx]
/* sectorsize */ [-s log=n|size=num]
/* version */ [-V]
devicename
<devicename> is required unless -d name=xxx is given.
<num> is xxx (bytes), xxxs (sectors), xxxb (fs blocks), xxxk (xxx KiB),
xxxm (xxx MiB), xxxg (xxx GiB), xxxt (xxx TiB) or xxxp (xxx PiB).
<value> is xxx (512 byte blocks).
[root@oldboy ~]# mkfs.xfs /dev/sdb1 -f
agsize (2560 blocks) too small, need at least 4096 blocks
磁盘分区太小了 无法格式化
Usage: mkfs.xfs
[root@oldboyedu ~]# mount /dev/sdb1 /mnt/
mount: /dev/sdb1 is already mounted or /mnt busy
磁盘分区 已经 挂载或/mnt正在使用中
/dev/sdb1 is already mounted on /mnt
如何给硬盘分区
命令：fdisk(只支持2T以内的硬盘)
常用参数：
n 创建新的主分区
d 删除
w 保存退出
p 主分区
e 拓展分区
l（L） 逻辑分区
t 改变分区类型
执行过程
[root@lusanbao ~]# fdisk /dev/sdb
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.
Command (m for help):
内容详解：
Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 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: 0x6df46197
Device Boot Start End Blocks Id System
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
主分区
e extended、
扩展分区
Select (default p):
默认就是 p
Partition number (1-4, default 1):
分区号 默认
First sector (2048-208895, default 2048):
磁盘分区中第1个扇区（从哪里开始） 默认
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-208895, default 208895):
磁盘分区中最后1个扇区
Last sector, +sectors or +size{K,M,G} (2048-208895, default 208895): +10M
Partition 1 of type Linux and of size 10 MiB is set
创建了分区号是1的 10MB的分区
Command (m for help): p
Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 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: 0x6df46197
Device Boot Start End Blocks Id System
/dev/sdb1 2048 22527 10240 83 Linux
10MB
Command (m for help): n
Partition type:
p primary (1 primary, 0 extended, 3 free)
e extended
Select (default p): e
Partition number (2-4, default 2):
First sector (22528-208895, default 22528):
Using default value 22528
Last sector, +sectors or +size{K,M,G} (22528-208895, default 208895):
Using default value 208895
Partition 2 of type Extended and of size 91 MiB is set
Command (m for help): n
Partition type:
p primary (1 primary, 1 extended, 2 free)
l logical (numbered from 5)
Select (default p): e
Invalid partition type `e'
Command (m for help): n
Partition type:
p primary (1 primary, 1 extended, 2 free)
l logical (numbered from 5)
Select (default p): l
Adding logical partition 5
First sector (24576-208895, default 24576):
Using default value 24576
Last sector, +sectors or +size{K,M,G} (24576-208895, default 208895): +20M
Partition 5 of type Linux and of size 20 MiB is set
Command (m for help): p
Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 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: 0x6df46197
Device Boot Start End Blocks Id System
/dev/sdb1 2048 22527 10240 83 Linux
/dev/sdb2 22528 208895 93184 5 Extended
/dev/sdb5 24576 65535 20480 83 Linux
创建2个分区 1个10MB的主分区 创建1个使用所有剩余空间的扩展 分区 1个20MB的逻辑分区
第1个里程碑-创建分区
[root@lusanbao ~]# fdisk /dev/sdb
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.
Command (m for help): p
Disk /dev/sdb: 106 MB, 106954752 bytes, 208896 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: 0x6df46197
Device Boot Start End Blocks Id System
Command (m for help): n
Partition type:
p primary (0 primary, 0 extended, 4 free)
e extended
Select (default p):
Using default response p
Partition number (1-4, default 1):
First sector (2048-208895, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-208895, default 208895):
Using default value 208895
Partition 1 of type Linux and of size 101 MiB is set
第2个里程碑-格式化 创建文件系统 mkfs make filesystem
[root@oldboyedu59 ~]# mkfs.xfs /dev/sdb1
meta-data=/dev/sdb1 isize=512 agcount=4, agsize=6464 blks
= sectsz=512 attr=2, projid32bit=1
= crc=1 finobt=0, sparse=0
data = bsize=4096 blocks=25856, imaxpct=25
= sunit=0 swidth=0 blks
naming =version 2 bsize=4096 ascii-ci=0 ftype=1
log =internal log bsize=4096 blocks=855, version=2
= sectsz=512 sunit=0 blks, lazy-count=1
realtime =none extsz=4096 blocks=0, rtextents=0
第3个里程碑-挂载
[root@oldboyedu59 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 99G 1.8G 97G 2% /
devtmpfs 980M 0 980M 0% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 9.6M 981M 1% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 197M 105M 93M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
[root@oldboyedu59 ~]# mount /dev/sdb1 /mnt/
[root@oldboyedu59 ~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 99G 1.8G 97G 2% /
devtmpfs 980M 0 980M 0% /dev
tmpfs 991M 0 991M 0% /dev/shm
tmpfs 991M 9.6M 981M 1% /run
tmpfs 991M 0 991M 0% /sys/fs/cgroup
/dev/sda1 197M 105M 93M 54% /boot
tmpfs 199M 0 199M 0% /run/user/0
/dev/sdb1 98M 5.3M 93M 6% /mnt
第4个里程碑-永久挂载
1./etc/rc.local
2./etc/fstab
文件内容详解：
[root@oldboyedu59 ~]# cat /etc/fstab
UUID=1e827748-cc43-4b1d-8bbc-9a85c239782d / xfs defaults 0 0
UUID=29a4ef75-7502-48df-b31c-c7c10264a7c8 /boot xfs defaults 0 0
UUID=60c45f5e-c78d-41fe-aa92-93d10de6def3 swap swap defaults 0 0
第1列：UUID或设备名称 第2列 第3列 第4列 第5列 第6列
查询系统的磁盘与对应的uuid 挂载点(入口) 文件系统类型 挂载参数 是否进行备份 是否开机自动检查
[root@oldboyedu59 ~]# tail -1 /etc/fstab
/dev/sdb1 /data xfs defaults 0 0
改错 /etc/fstab 文件导致进入紧急模式提示翻译：
Welcome to emergency mode 欢迎进入紧急模式/维护模式
磁盘故障或/etc/fstab
Give root password for manintenance
给出root密码进入维护模式
(或按ctrl +d 继续 )
单词科普：
field 列 字段 域
failed 失败
文件系统类型：
CentOS7 默认的是xfs
CentOS6 5 默认 ext系列
fdisk和parted区别
fdisk parted
共同 磁盘分区 磁盘分区
区别 支持2TB以内硬盘 大于2TB磁盘
支持MBR分区表 MBR GPT（支持更大的硬盘和更多的主分区）
parted （实时生效，支持任何大小） 命令简介
常用参数：
p print 显示磁盘信息
mktable mklabel make partition table 创建磁盘分区表 MBR GPT
mkpart make partition 创建磁盘分区
rm 删除磁盘分区
q quit 退出磁盘分区
创建1个主分区 10M
(parted) p
Error: /dev/sdc: unrecognised disk label #无法识别的
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 107MB
Sector size (logical/physical): 512B/512B
Partition Table: unknown #未知
Disk Flags:
(parted) mktable gpt
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 107MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
(parted) mkpart primary 0 10
Warning: The resulting partition is not properly aligned for best performance.
Ignore/Cancel? i
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 107MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 10.0MB 9983kB primary
名词解释（硬盘分区系列）
primary 主分区
extended 扩展分区
logical 逻辑分区
partition 分区
partition table 分区表
