第16章 Linux磁盘管理体系
满足本能需求，比满足意识需求更重要
分区知识：
（1）什么是分区，为什么要分区？
（2）磁盘和分区在Linux里的命名。
（3）磁盘分区类型和特点：
（4）磁盘分区工作原理：
（5）磁盘分区实战
（6）生产场景分区方案：4种。参考前面课程。
1.parted分区——传统的MBR（Master boot Re
格式化分区：
1.创建两个分区
2.查看/dev/sdb下分区 （ls -l /dev/sdb*）
3.mkfs -t ext4 /dev/sdb1 ##格式化ext4文件系统（生成一定数量的Indoe和Block)
4.mount -t exxt4 /dev/sdb1/mnt ###挂载到mnt ###（df -h查看挂载）
5.cat /proc/mounts ###查看挂载结果
6.touch /mnt/woshi ##测试（在mnt下创建一个文件）ls /mnt 查看
7.umount /mnt ###卸载mnt df -h (查看成功与否）
[root@keyan
~]# mount /dev/sdb2/opt ###没有格式化不能挂载
mount: can't find /dev/sdb2/opt in /etc/fstab
8.mkfs.xfs /dev/sdb2 ###格式化xfs文件系统
9.mount -t xfs /dev/sdb2 /opt ###挂载到/opt下（df -h查看）
10.cat /etc/fstab ##查看开机自动挂载 （编辑vim 实现开机挂载)
第一列 设备 /dev/sdb2
第二列 挂载点 /opt
第三列 文件系统类型 xfs
第四列 默认挂载类型 defaults
第五烈 是否备份
第六列 是否开机设备挂载
11.blkid 列出当前系统中已挂载的文件类型 （tail -1 /etc/fstab查看开机自动挂载的最后一个） ###df -h主分区Block 大小 df -ih 主分区Inode大小
12.dumpe2fs /dev/sdb1 ###查看ext文件内部细节
dumpe2fs /dev/sdb1|egrep -i "size" ###在文件内部细节过滤出有size关键字的
备注：放入/etc/rc.local实现自动挂载，但不推荐。
/sbin/mount -t xfs /dev/sdb2 /opt
13.mkfs -t ext4 -b 4096 -I 512 /dev/sdb1 ###指定block和inode大小（这里指定大小4096和inode512) dumpe2fs /dev/sdb1|egrep -i "size" 查看更改
14. free -m 查看swap 大小空间
15.增加swap
partprobe /dev/sdb ####更新/dev/sdb
mkswap /dev/sdb4 ###把/dev/sdb4创建swap
free -m ###查看大小
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
业：如何用一条fdisk命令回车完成上述分区。
1.parted分区——传统的MBR（Master boot Re
优势：创建文件系统
需求：Raid5大小6T ，已装系统，额外添加4块2T盘
硬盘总分区大小：6。2T
/data0 4.8T
/data1 1T
4T (无需格式化，做DRBD+Hearbeat+MySQL高可用集群）
2.文件系统
什么是文件系统？
计算机存储和组织数据的方法或机制。
为什么需要文件系统？
磁盘、物理介质、磁粒子物理元素。硬件是需要软件驱动使用，磁盘需要文件系统驱动。
文件系统实现通过磁盘管理规划、存取数据。
文件系统有哪些种类？
Windows、NTFS、fat32、msdos
Linux:ext2、ext3(C5)、ext(C6)、Xfs(C7)
创建文件系统实践
挂载：
[root@keyan~]# fdisk /dev/sdb
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.
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): n
Partition number (1-128, default 1):
First sector (34-2097118, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-2097118, default 2097118): +100
First sector (34-2097118, default 2048):
Last sector, +sectors or +size{K,M,G,T,P} (2048-2097118, default 2097118): +150M
Created partition 1
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: gpt
Disk identifier: 78F96531-A47F-4A7A-8732-E481A2BECDBB
# Start End Size Type Name
1 2048 309247 150M Linux filesyste
Command (m for help): n
Partition number (2-128, default 2):
First sector (34-2097118, default 309248):
Last sector, +sectors or +size{K,M,G,T,P} (309248-2097118, default 2097118): +150m
Created partition 2
Command (m for help): n
Partition number (3-128, default 3):
First sector (34-2097118, default 616448):
Last sector, +sectors or +size{K,M,G,T,P} (616448-2097118, default 2097118): +150M
Created partition 3
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: gpt
Disk identifier: 78F96531-A47F-4A7A-8732-E481A2BECDBB
# Start End Size Type Name
1 2048 309247 150M Linux filesyste
2 309248 616447 150M Linux filesyste
3 616448 923647 150M Linux filesyste
Command (m for help): wq
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
You have new mail in /var/spool/mail/root
[root@keyan~]# ls -l /dev/sdb*
brw-rw---- 1 root disk 8, 16 Mar 29 11:47 /dev/sdb
brw-rw---- 1 root disk 8, 17 Mar 29 11:47 /dev/sdb1
brw-rw---- 1 root disk 8, 18 Mar 29 11:47 /dev/sdb2
brw-rw---- 1 root disk 8, 19 Mar 29 11:47 /dev/sdb3
[root@keyan~]# mkfs -t ext4 /dev/sdb1 ======
mke2fs 1.42.9 (28-Dec-2013)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
Stride=0 blocks, Stripe width=0 blocks
38456 inodes, 153600 blocks
7680 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=33816576
19 block groups
8192 blocks per group, 8192 fragments per group
2024 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729
Allocating group tables: done
Writing inode tables: done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: done
You have new mail in /var/spool/mail/root
[root@keyan~]# mount -t ext4 /dev/sdb1 /mnt
[root@keyan~]# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/sda3 20G 2.1G 17G 11% /
devtmpfs 477M 0 477M 0% /dev
tmpfs 488M 0 488M 0% /dev/shm
tmpfs 488M 32M 456M 7% /run
tmpfs 488M 0 488M 0% /sys/fs/cgroup
/dev/sda1 197M 102M 95M 52% /boot
tmpfs 98M 0 98M 0% /run/user/0
/dev/sdb1 142M 1.6M 130M 2% /mnt
You have new mail in /var/spool/mail/root
[root@keyan~]# touch /mnt/woshi
[root@keyan~]# cat /mnt
cat: /mnt: Is a directory
[root@keyan~]# ls
1 abc.txt data oldboy oldboy.txt sudo woshi
[root@keyan~]# ls /mnt
lost+found woshi
方法二：
[root@oldboyedu ~]# mount -t xfs /dev/sdb2 /opt
You have new mail in /var/spool/mail/root
[root@oldboyedu ~]# df -h|grep opt
/dev/sdb2 97M 5.3M 92M 6% /opt
[root@oldboyedu ~]# touch /opt/oldgirl
[root@oldboyedu ~]# ls /opt
oldgirl
如何开机自动挂载？
/etc/fstab 开机自动挂载
几列？ 6列
UUID=25027b5a-f7c1-4c54-af0d-52f48755ff5a / xfs defaults
UUID=dd5867b8-2d24-4526-9c88-8ce8db3175cb /boot xfs defaults
UUID=1f30dc74-c1df-411e-8e78-b8a3d005e5fd swap
dumpe2fs /dev/sdb1
fsck 磁盘检查和修复
swap作用，内存不够充当内存
文件系统原理（ext文件系统）、文件系统特点
企业中如何选择文件系统
企业里如何优化文件系统
[root@keyan~]#fdisk /dev/sdb
WARNING: fdisk GPT support is currently new, and therefore in an experimental phase. Use at your own discretion.警告:fdisk GPT支持目前是新的，因此还处于试验阶段。使用时请自行决定。
Welcome to fdisk (util-linux 2.23.2).欢迎来到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.更改只会保留在内存中，直到您决定编写它们。
在使用写命令之前要小心。
Command (m for help): p 命令(m寻求帮助):
实操：
1.创建分区：
2.m
Command (m for help): m
Command action
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition
g create a new empty GPT partition table
G create an IRIX (SGI) partition table
l list known partition types ###列出已知分区类型
m print this menu
n add a new partition
o create a new empty DOS partition table
p print the partition table
q quit without saving changes
s create a new empty Sun disklabel
t change a partition's system id ###更改一个系统分区Id
u change display/entry units
v verify the partition table
w write table to disk and exit
x extra functionality (experts only)
Command (m for help):t
Partition number (1-3, default 3): 2
Hex code (type L to list all codes): L
Hex code (type L to list all codes):8e ###修改分区类型Linux为Linux LVM
Changed type of partition 'Linux' to 'Linux LVM'
Command (m for help): p
Disk /dev/sdb: 1073 MB, 1073741824 bytes, 2097152 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: 0xdd380bb6
Device Boot Start End Blocks Id System
/dev/sdb1 2048 309247 153600 83 Linux
/dev/sdb2 309248 616447 153600 8e Linux LVM ###以修改完毕
/dev/sdb3 616448 923647 153600 83 Linux
[root@keyan
~]#parted /dev/sdc
GNU Parted 3.1
Using /dev/sdc
Welcome to GNU Parted! Type 'help' to view a list of commands.
(parted)p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 1074MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt #####mktable gpt 修改分区格式
Disk Flags:
Number Start End Size File system Name Flags
(parted)mkpart primary 0 480 ###创建第一个主分区480M
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: 1074MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 480MB 480MB primary
(parted)mkpart primary 481 580 ###创建第二个自主分区100M
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 1074MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 480MB 480MB primary
2 481MB 580MB 98.6MB primary
(parted)mkpart logic 581 600 ###创建一个20M逻辑分区
(parted)p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 1074MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 480MB 480MB primary
2 481MB 580MB 98.6MB primary
3 581MB 600MB 18.9MB logic
(parted)rm 3 ###删除逻辑分区
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 1074MB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 17.4kB 480MB 480MB primary
2 481MB 580MB 98.6MB primary
(parted)mklabel msdos ###修改分区格式为msdos
Warning: The existing disk label on /dev/sdc will be destroyed and all data on this disk will be lost. Do you
want to continue?
Yes/No? Y
(parted) p
Model: VMware, VMware Virtual S (scsi)
Disk /dev/sdc: 1074MB
Sector size (logical/physical): 512B/512B
Partition Table:msdos ###分区格式为msdos
Disk Flags:
Number Start End Size Type File system Flags
[root@keyan
~]# ls -l /dev/sd* ###查看挂载情况
brw-rw---- 1 root disk 8, 0 Mar 30 23:36 /dev/sda
brw-rw---- 1 root disk 8, 1 Mar 30 23:36 /dev/sda1
brw-rw---- 1 root disk 8, 2 Mar 30 23:36 /dev/sda2
brw-rw---- 1 root disk 8, 3 Mar 30 23:36 /dev/sda3
brw-rw---- 1 root disk 8, 16 Mar 30 23:43 /dev/sdb
brw-rw---- 1 root disk 8, 32 Mar 31 00:18 /dev/sdc
