Linux文件系统管理
Linux文件系统管理
1、文件系统构成
/usr/bin、/bin：存放所有用户可以执行的命令
/usr/sbin、/sbin：存放只有root可以执行的命令
/home：用户缺省宿主目录 www.2cto.com
/proc：虚拟文件系统，存放当前内存镜像
/dev：存放设备文件
/lib：存放系统程序运行所需的共享库
/lost+found：存放一些系统出错的检查结果
/tmp：存放临时文件
/etc：系统配置文件
/var：包含经常发生变动的文件，如邮件、日志文化、计划任务等
/usr：存放所有命令、库、手册页等 www.2cto.com
/mnt：临时文件系统的安装点
/boot：内核文件及自举程序文件保存位置
1）常用命令
查看分区情况：df
[root@localhost ~]# df
文件系统 1K-块 已用 可用 已用% 挂载点
/dev/sda1 5039616 623020 4160596 14% /
tmpfs 515396 0 515396 0% /dev/shm
/dev/sda5 1007896 44760 911936 5% /home
/dev/sda2 5039616 1737788 3045828 37% /usr
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用%% 挂载点
/dev/sda1 4.9G 609M 4.0G 14% /
tmpfs 504M 0 504M 0% /dev/shm
/dev/sda5 985M 44M 891M 5% /home
/dev/sda2 4.9G 1.7G 3.0G 37% /usr
[root@localhost ~]# df -m
文件系统 1M-块 已用 可用 已用% 挂载点
/dev/sda1 4922 609 4064 14% /
tmpfs 504 0 504 0% /dev/shm
/dev/sda5 985 44 891 5% /home
/dev/sda2 4922 1698 2975 37% /usr
[root@localhost ~]#
查看文件、目录大小：du
[root@localhost ~]# du -h /etc/services
628K /etc/services
[root@localhost ~]# du -sh /etc
27M /etc
[root@localhost ~]#
检测修复文件系统：fsck、e2fsck（单用户模式执行）
判断文件类型：file
2）使用光驱
挂载光驱
[root@localhost ~]# mount /dev/cdrom /mnt/cdrom
mount: block device /dev/sr0 is write-protected, mounting read-only
[root@localhost ~]#
如果没有/mnt/cdrom目录，先手工创建该目录。
查看挂载信息
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用%% 挂载点
/dev/sda1 4.9G 609M 4.0G 14% /
tmpfs 504M 0 504M 0% /dev/shm
/dev/sda5 985M 44M 891M 5% /home
/dev/sda2 4.9G 1.7G 3.0G 37% /usr
/dev/sr0 3.5G 3.5G 0 100% /mnt/cdrom
[root@localhost ~]#
卸载光驱
[root@localhost ~]# umount /mnt/cdrom
或者
[root@localhost ~]# eject
3）添加磁盘或分区
现在用虚拟机添加了一块硬盘sdb，重启系统后查看新添加的硬盘是否被识别：
[root@localhost ~]# dmesg | grep sdb
sd 2:0:1:0: [sdb] 10485760 512-byte logical blocks: (5.36 GB/5.00 GiB)
sd 2:0:1:0: [sdb] Write Protect is off
sd 2:0:1:0: [sdb] Mode Sense: 61 00 00 00
sd 2:0:1:0: [sdb] Cache data unavailable
sd 2:0:1:0: [sdb] Assuming drive cache: write through
sd 2:0:1:0: [sdb] Cache data unavailable
sd 2:0:1:0: [sdb] Assuming drive cache: write through
sdb:
sd 2:0:1:0: [sdb] Cache data unavailable
sd 2:0:1:0: [sdb] Assuming drive cache: write through
sd 2:0:1:0: [sdb] Attached SCSI disk
[root@localhost ~]#
3.1）分区：fdisk
查看新添加的硬盘信息
[root@localhost ~]# fdisk -l /dev/sdb
Disk /dev/sdb: 5368 MB, 5368709120 bytes
255 heads, 63 sectors/track, 652 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
[root@localhost ~]#
对硬盘进行分区
fdisk /dev/sdb
常用命令：
m 帮助
p 显示分区表
n 添加新分区
t 改变分区文件系统类型
d 删除分区
w 保存退出
q 不保存退出
[root@localhost ~]# fdisk /dev/sdb
Device contains neither a valid DOS partition table, nor Sun, SGI or OSF disklabel
Building a new DOS disklabel with disk identifier 0x118c05b0.
Changes will remain in memory only, until you decide to write them.
After that, of course, the previous content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').
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
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)
Command (m for help): p
3.2）创建文件系统（格式化）：mkfs
[root@localhost ~]# mkfs.ext4 /dev/sdb1
mke2fs 1.41.12 (17-May-2010)
文件系统标签=
操作系统:Linux
块大小=4096 (log=2)
分块大小=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
160960 inodes, 642592 blocks
32129 blocks (5.00%) reserved for the super user
第一个数据块=0
Maximum filesystem blocks=658505728
20 block groups
32768 blocks per group, 32768 fragments per group
8048 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
正在写入inode表: 完成
Creating journal (16384 blocks): 完成
Writing superblocks and filesystem accounting information: 完成
This filesystem will be automatically checked every 31 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
3.3）尝试挂载：mount
把/dev/sdb1挂载到/web空目录
先创建/web目录
[root@localhost ~]# mkdir /web
挂载
[root@localhost ~]# mount /dev/sdb1 /web
查看是否挂载成功
[root@localhost ~]# df -h
文件系统 容量 已用 可用 已用%% 挂载点
/dev/sda1 4.9G 609M 4.0G 14% /
tmpfs 504M 0 504M 0% /dev/shm
/dev/sda5 985M 44M 891M 5% /home
/dev/sda2 4.9G 1.7G 3.0G 37% /usr
/dev/sdb1 2.5G 68M 2.3G 3% /web
[root@localhost ~]#
3.4）写入配置文件：/etc/fstab
[root@localhost ~]# more /etc/fstab
#
# /etc/fstab
# Created by anaconda on Wed Dec 5 04:36:40 2012
#
# 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=1782302e-7804-4b32-9e59-04aac3651342 / ext4 defaul
ts 1 1
UUID=e5ec7966-8a82-438a-b929-962d375bb1e5 /home ext4 defaul
ts 1 2
UUID=926c0281-29b0-4ab0-9483-c1066462d508 /usr ext4 defaul
ts 1 2
UUID=ac208436-48b7-4bfa-b25d-758af1ea9019 swap swap defaul
ts 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
[root@localhost ~]#
由以下部分组成
物理分区名/卷标 挂载点 文件系统 缺省设置 是否检测 检测顺序
proc /proc proc defaults 1/0 0/1/2
把我们刚新加的分区配置进去，让系统引导的时候自动加载
[root@localhost ~]# vi /etc/fstab
#
# /etc/fstab
# Created by anaconda on Wed Dec 5 04:36:40 2012
#
# 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=1782302e-7804-4b32-9e59-04aac3651342 / ext4 defaults 1 1
UUID=e5ec7966-8a82-438a-b929-962d375bb1e5 /home ext4 defaults 1 2
UUID=926c0281-29b0-4ab0-9483-c1066462d508 /usr ext4 defaults 1 2
UUID=ac208436-48b7-4bfa-b25d-758af1ea9019 swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/sdb1 /web ext4 defaults 1 2
~
~
"/etc/fstab" 17L, 936C written
[root@localhost ~]#
2、磁盘配额
1）开启分区配额功能
1.1）编辑/etc/fstab文件，在挂载属性上加上标志：usrquota（用户配额）或grpquota（用户组配额）
假如/home这个分区，限制每个用户只能使用50M的空间：
加载用户配额设置
[root@localhost ~]# vi /etc/fstab
#
# /etc/fstab
# Created by anaconda on Wed Dec 5 04:36:40 2012
#
# 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=1782302e-7804-4b32-9e59-04aac3651342 / ext4 defaults 1 1
UUID=e5ec7966-8a82-438a-b929-962d375bb1e5 /home ext4 defaults 1 2
UUID=926c0281-29b0-4ab0-9483-c1066462d508 /usr ext4 defaults 1 2
UUID=ac208436-48b7-4bfa-b25d-758af1ea9019 swap swap defaults 0 0
tmpfs /dev/shm tmpfs defaults 0 0
devpts /dev/pts devpts gid=5,mode=620 0 0
sysfs /sys sysfs defaults 0 0
proc /proc proc defaults 0 0
/dev/sdb1 /web ext4 defaults,usrquota 1 2
~
"/etc/fstab" 17L, 945C written
[root@localhost ~]#
临时开启分区配额功能
[root@localhost ~]# mount -o remount,usrquota /home
1.2）创建配额数据库：quotacheck -cvu /home
[root@localhost ~]# quotacheck -cvu /web
quotacheck: Mountpoint (or device) /web not found or has no quota enabled.
quotacheck: Cannot find filesystem to check or filesystem not mounted with quota option.
[root@localhost ~]# quotacheck -cvu /home
quotacheck: Your kernel probably supports journaled quota but you are not using it. Consider switching to journaled quota to avoid running quotacheck after an unclean shutdown.
quotacheck: Scanning /dev/sda5 [/home] done
quotacheck: Cannot stat old user quota file: 没有那个文件或目录
quotacheck: Old group file not found. Usage will not be substracted.
quotacheck: Checked 387 directories and 1626 files
quotacheck: Old file not found.
[root@localhost ~]#
/home下已经有了aquota.user这个文件
[root@localhost ~]# ls /home
aquota.user lixunxuan luixaofeng luxh01 luxh03 luxh05 yekai
cnblogs001 lost+found luxh luxh02 luxh04 luxiaofeng
[root@localhost ~]#
1.3）启动配额功能
[root@localhost ~]# quotaon /home
[root@localhost ~]#
如果要关闭配额功能
[root@localhost ~]# quotaoff /home
[root@localhost ~]#
1.4）编辑用户配额
edquota 用户名
[root@localhost ~]# edquota luxh01
Disk quotas for user luxh01 (uid 1001):
Filesystem blocks soft hard inodes soft hard
/dev/sda5 8 0 51200 2 0 0
~
blocks soft hard 限制用户能使用的空间大小
inodes soft hard 限制用户能创建多少个文件
查看luxh01用户的配额信息
[root@localhost ~]# quota luxh01
Disk quotas for user luxh01 (uid 1001):
Filesystem blocks quota limit grace files quota limit grace
/dev/sda5 8 0 51200 2 0 0
[root@localhost ~]#
查看所有用户的配额信息
[root@localhost ~]# repquota /home
*** Report for user quotas on device /dev/sda5
Block grace time: 7days; Inode grace time: 7days
Block limits File limits
User used soft hard grace used soft hard grace
----------------------------------------------------------------------
root -- 26936 0 0 1964 0 0
luxh -- 8 0 0 2 0 0
lihuai -- 36 0 0 9 0 0
luixaofeng -- 32 0 0 8 0 0
lixunxuan -- 32 0 0 8 0 0
luxiaofeng -- 32 0 0 8 0 0
luxh01 -- 8 0 51200 2 0 0
luxh02 -- 4 0 0 1 0 0
luxh03 -- 4 0 0 1 0 0
luxh04 -- 4 0 0 1 0 0
luxh05 -- 4 0 0 1 0 0
cnblogs001 -- 32 0 0 8 0 0
[root@localhost ~]#
复制用户配额信息：
edquota -p 模板用户 复制用户1 复制用户2
[root@localhost ~]# edquota -p luxh01 luxh02 luxh03
3、备份
1）cp命令备份举例
备份目录
cp -Rpu 备份目录 目标目录
-p 保持备份目录及文件属性
-u 增量备份
[root@localhost ~]# cp -p /etc/inittab /backup/inittab_20130103.bak
远程备份可以用scp
2）tar命令打包备份
备份/etc目录，可以同时备份多个目录
[root@localhost ~]# tar -zcf /backup/etc_20130103.tar.gz /etc
还原/etc目录，默认还原到打包文件源目录
[root@localhost ~]# tar -zxf /backup/etc_20130103.tar.gz
只还原指定的文件，如/etc/passwd，注意，在命令中要写成etc/passwd，解压到当前目录。
[root@localhost ~]# tar -zvf /backup/etc_20130103.tar.gz etc/passwd
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