linux系统中的磁盘管理

1.本地储存设备的识别
fdisk -l ##真实存在的设备（不一定是系统识别的）
cat /proc/partitions##系统识别的设备
blkid ##系统可以使用的设备
df##系统正在挂载的设备



####2.设备的挂载和卸载####
1.设备名称
/dev/xdx ##/dev/hd0 /dev/hd1 /dev/sda /dev/sdb /dev/sda1 /dev/sdb1
/dev/sr0 ##光驱
/dev/mapper/*##虚拟设备（用软件模拟出来的）

2.设备的挂载
mount 设备 挂载点
mount /dev/sdb1 /mnt##挂载sdb1到mnt
umount /mnt | /dev/sdb1 ##卸载
mount -o ro /dev/sdb1 /mnt ##只读挂载
mount ##查看挂载信息
monut -o remount,rw /dev/sdb1|/mnt ##重新读写挂载

3.解决设备正忙问题
[root@foundation0 ~]# umount /mnt/
umount: /mnt: target is busy.
(In some cases useful info about processes that use
the device is found by lsof(8) or fuser(1))

解决方法1：
lsof /mnt
[root@foundation0 ~]# lsof /mnt/
lsof: WARNING: can’t stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs
Output information may be incomplete.
COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME
bash 6968 root cwd DIR 8,17 4096 5 /mnt

kill -9 6968
umount /mnt

解决方法2：
[root@foundation0 ~]# fuser -kvm /mnt/
USER PID ACCESS COMMAND
/mnt: root kernel mount /mnt
kiosk 7112 …c… bash
root 7182 …c… bash

###3.磁盘分区
1.fdisk -l
2.fdisk /dev/vdb
m ##查看帮助
a toggle a bootable flag
b edit bsd disklabel
c toggle the dos compatibility flag
d delete a partition##删除
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##新建
o create a new empty DOS partition table
p print the partition table##显示分区信息
q quit without saving changes##退出
s create a new empty Sun disklabel
t change a partition’s system id##修改分区id
u change display/entry units
v verify the partition table
w write table to disk and exit##保存
x extra functionality (experts only)

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):
First sector (2048-20971519, default 2048):
Using default value 2048
Last sector, +sectors or +size{K,M,G} (2048-20971519, default 20971519): +500M
Partition 1 of type Linux and of size 500 MiB is set

Command (m for help): p

Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x9e92ec35

Device Boot Start End Blocks Id System
/dev/vdb1 2048 1026047 512000 83 Linux

##当系统已经有三个主分区时
Command (m for help): n
Partition type:
p primary (3 primary, 0 extended, 1 free)
e extended
Select (default e): ##当有3个主分区时需要先划分扩展分区
Using default response e
Selected partition 4
First sector (3074048-20971519, default 3074048):
Using default value 3074048
Last sector, +sectors or +size{K,M,G} (3074048-20971519, default 20971519):
Using default value 20971519
Partition 4 of type Extended and of size 8.5 GiB is set

Disk /dev/vdb: 10.7 GB, 10737418240 bytes, 20971520 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: 0x9e92ec35

Device Boot Start End Blocks Id System
/dev/vdb1 2048 1026047 512000 83 Linux
/dev/vdb2 1026048 2050047 512000 83 Linux
/dev/vdb3 2050048 3074047 512000 83 Linux
/dev/vdb4 3074048 20971519 8948736 5 Extended
##把所有剩余空间都给扩展分区

####4.给设备安装文件系统

mkfs.xfs /dev/vdb1
mount /dev/vdb1 /mnt

####5.swap分区管理
1）swap分区建立
mkswap /dev/vdb6
swapon -a /dev/vdb6
swapon -s
Filename Type Size Used Priority
/dev/vdb6 partition 511996 0 -1

/dev/vdb6 swap swap defaults 0 0

2)swap分区删除
vim /etc/fstab

swapoff /dev/vdb6
swapon -s

####6.配额#####
1.分区，格式化
mkdir /public
mount -o userquota /dev/vdb7 /public

edquota -u student
Disk quotas for user student (uid 1000):
Filesystem blocks soft hard inodes soft hard
/dev/vdb7 20480 0 20480 1 0 0

vim /etc/fstab永久挂载

/dev/vdb7 /public xfs defaults,usrquota 0 0

测试：
[student@server ~]$ dd if=/dev/zero of=/public/studentfile bs=1M count=500

#####7.磁盘加密####

cryptsetup luksFormat /dev/vdb8
YES
cryptsetup open /dev/vdb8 westos
mkfs.xfs /dev/mapper/westos
mount /dev/mapper/westos /mnt/
touch /mnt/file{1…10}
umount /mnt/
cryptsetup close westos##关闭之后，/dev/mapper/westos文件消失，挂载原始设备也不能查看其中的内容
cryptsetup open /dev/vdb8 linux
mount /dev/mapper/linux /mnt/