zhi ngzhiton'g/dev
主设备号 （major number）
标识设备类型
次设备号 （minor number）
标识同一种类型中不同设备
[rhel@localhost ~]$ ll /dev/
brw-rw----. 1 root disk 8, 0 Feb 19 18:55 sda
brw-rw----. 1 root disk 8, 1 Feb 19 18:55 sda1
brw-rw----. 1 root disk 8, 2 Feb 19 18:55 sda2
brw-rw----. 1 root disk 8, 3 Feb 19 18:55 sda3
设备id不占有磁盘块，数据存放在inode中
mknod：创建块或字符特殊文件
NAME
mknod - make block or character special files
SYNOPSIS
mknod [OPTION]... NAME TYPE [MAJOR MINOR]
-m MODE 设定设备文件权限
[root@localhost ~]# mknod mydev c 66 0
[root@localhost ~]# ll
total 96
-rw-r--r--. 1 root root 989 Feb 18 17:09 adduser.sh
-rw-------. 1 root root 4080 Jun 21 2015 anaconda-ks.cfg
-rw-r--r--. 1 root root 95 Feb 17 20:23 case.sh
-rw-r--r--. 1 root root 42001 Jun 21 2015 install.log
-rw-r--r--. 1 root root 9154 Jun 21 2015 install.log.syslog
crw-r--r--. 1 root root 66, 0 Feb 19 19:23 mydev
-rw-r--r--. 1 root root 315 Feb 17 19:36 random.sh
-rwxr-xr-x. 1 root root 196 Nov 19 18:37 second.sh
-rw-r--r--. 1 root root 200 Nov 19 22:26 sum.sh
-rwxr-xr-x. 1 root root 118 Nov 19 18:53 third.sh
-rwxr-xr-x. 1 root root 425 Nov 19 18:48 user2.sh
-rwxr-xr-x. 1 root root 177 Nov 19 20:23 userexit.sh
[root@localhost ~]# mknod -m 640 mydev2 c 66 1
[root@localhost ~]# ll
total 96
-rw-r--r--. 1 root root 989 Feb 18 17:09 adduser.sh
-rw-------. 1 root root 4080 Jun 21 2015 anaconda-ks.cfg
-rw-r--r--. 1 root root 95 Feb 17 20:23 case.sh
-rw-r--r--. 1 root root 42001 Jun 21 2015 install.log
-rw-r--r--. 1 root root 9154 Jun 21 2015 install.log.syslog
crw-r--r--. 1 root root 66, 0 Feb 19 19:23 mydev
crw-r-----. 1 root root 66, 1 Feb 19 19:23 mydev2
-rw-r--r--. 1 root root 315 Feb 17 19:36 random.sh
-rwxr-xr-x. 1 root root 196 Nov 19 18:37 second.sh
-rw-r--r--. 1 root root 200 Nov 19 22:26 sum.sh
-rwxr-xr-x. 1 root root 118 Nov 19 18:53 third.sh
-rwxr-xr-x. 1 root root 425 Nov 19 18:48 user2.sh
-rwxr-xr-x. 1 root root 177 Nov 19 20:23 userexit.sh
设备文件是访问设备的入口
[root@localhost ~]# echo "hello" >> /dev/pts/1
[root@localhost ~]#
[rhel@localhost ~]$ hello
[rhel@localhost ~]$
[rhel@localhost ~]$
硬盘设备的设备文件名：
IDE, ATA：hd
SATA：sd
SCSI: sd
USB: sd
a,b,c,...来区别同一种类型下的不同设备
IDE:
第一个IDE口：主、从
/dev/hda, /dev/hdb
第二个IDE口：主、从
/dev/hdc, /dev/hdd
sda, sdb, sdc, ...
hda:
hda1: 第一个主分区
hda2:
hda3:
hda4:
hda5: 第一个逻辑分区
查看当前系统识别了几块硬盘：
fdisk -l [/dev/to/some_device_file]
[root@localhost ~]# fdisk -l
Disk /dev/sda: 21.5 GB, 21474836480 bytes
255 heads, 63 sectors/track, 2610 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: 0x0004cc30
Device Boot Start End Blocks Id System
/dev/sda1 * 1 39 307200 83 Linux （默认系统bootloader）
Partition 1 does not end on cylinder boundary.
/dev/sda2 39 2350 18566144 83 Linux
/dev/sda3 2350 2611 2097152 82 Linux swap / Solaris
管理磁盘分区：
fdisk /dev/sda
p: 显示当前硬件的分区，包括没保存的改动
n: 创建新分区
e: 扩展分区
p: 主分区
d: 删除一个分区
w: 保存退出
q: 不保存退出
t: 修改分区类型
L:
l: 显示所支持的所有类型
partprobe ：通知内核重读分区表
创建分区fdisk
Command (m for help): n
Command action
e extended
p primary partition (1-4)
e
Partition number (1-4):
Value out of range.
Partition number (1-4): 4
First cylinder (263-2610, default 263):
Using default value 263
Last cylinder, +cylinders or +size{K,M,G} (263-2610, default 2610):
Using default value 2610
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
+2G
Invalid partition number for type `+'
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (263-2610, default 263): +2G
Value out of range.
First cylinder (263-2610, default 263):
Using default value 263
Last cylinder, +cylinders or +size{K,M,G} (263-2610, default 2610): +2G
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (525-2610, default 525):
Using default value 525
Last cylinder, +cylinders or +size{K,M,G} (525-2610, default 2610): +5G
Command (m for help): n
Command action
l logical (5 or over)
p primary partition (1-4)
l
First cylinder (1179-2610, default 1179):
Using default value 1179
Last cylinder, +cylinders or +size{K,M,G} (1179-2610, default 2610): +1G
Command (m for help): w
The partition table has been altered!
Calling ioctl() to re-read partition table.
Syncing disks.
[root@localhost ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 307200 sda1
8 2 18566144 sda2
8 3 2097152 sda3
8 16 20971520 sdb
8 17 2104483 sdb1
8 20 1 sdb4
8 21 2104483 sdb5
8 22 5253223 sdb6
8 23 1060258 sdb7
[root@localhost ~]# partprobe /dev/sdb
[root@localhost ~]# cat /proc/partitions
major minor #blocks name
8 0 20971520 sda
8 1 307200 sda1
8 2 18566144 sda2
8 3 2097152 sda3
8 16 20971520 sdb
8 17 2104483 sdb1
8 20 1 sdb4
8 21 2104483 sdb5
8 22 5253223 sdb6
8 23 1060258 sdb7
查看内核支持的文件系统
[root@localhost ~]# cat /proc/filesystems
nodev sysfs
nodev rootfs
nodev bdev
nodev proc
nodev cgroup
nodev cpuset
nodev tmpfs
nodev devtmpfs
nodev binfmt_misc
nodev debugfs
nodev securityfs
nodev sockfs
nodev usbfs
nodev pipefs
nodev anon_inodefs
nodev inotifyfs
nodev devpts
nodev ramfs
nodev hugetlbfs
iso9660
nodev pstore
nodev mqueue
nodev selinuxfs
ext4
[root@localhost ~]#
创建文件系统
mkfs: make file system （统一调用文件格式化的函数）
-t FSTYPE （指定文件类型）
mkfs -t ext2 = mkfs.ext2
mkfs -t ext3 = mkfs.ext3
[root@localhost ~]# mkfs.
mkfs.cramfs mkfs.ext2 mkfs.ext3 mkfs.ext4 mkfs.ext4dev mkfs.msdos mkfs.vfat
[root@localhost ~]# mkfs.
[root@localhost ~]# ll /sbin/ | grep mkfs
-rwxr-xr-x. 1 root root 10336 Aug 11 2014 mkfs
-rwxr-xr-x. 1 root root 26208 Aug 11 2014 mkfs.cramfs
-rwxr-xr-x. 5 root root 68960 Jun 27 2014 mkfs.ext2
-rwxr-xr-x. 5 root root 68960 Jun 27 2014 mkfs.ext3
-rwxr-xr-x. 5 root root 68960 Jun 27 2014 mkfs.ext4
-rwxr-xr-x. 5 root root 68960 Jun 27 2014 mkfs.ext4dev
lrwxrwxrwx. 1 root root 7 Jun 21 2015 mkfs.msdos -> mkdosfs
lrwxrwxrwx. 1 root root 7 Jun 21 2015 mkfs.vfat -> mkdosfs
[root@localhost ~]#
[root@localhost ~]# mkfs -t ext3 /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label= （卷标）
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
131648 inodes, 526120 blocks （inode数量及block数量）
26306 blocks (5.00%) reserved for the super user （预留super block）
First data block=0
Maximum filesystem blocks=541065216
17 block groups （块组）
32768 blocks per group, 32768 fragments per group
7744 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (16384 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 24 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
专门管理ext系列文件：
mke2fs
-j: 创建ext3类型文件系统
-b BLOCK_SIZE: 指定块大小，默认为4096；可用取值为1024、2048或4096；
-L LABEL：指定分区卷标；
-m #: 指定预留给超级用户的块数百分比
-i #: 用于指定为多少字节的空间创建一个inode，默认为8192；这里给出的数值应该为块大小的2^n倍；
-N #: 指定inode个数；
-F: 强制创建文件系统；
-E: 用户指定额外文件系统属性;
1、mke2fs /dev/sdb5创建ext2文件系统
[root@localhost ~]# mke2fs /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
131648 inodes, 526120 blocks
26306 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=541065216
17 block groups
32768 blocks per group, 32768 fragments per group
7744 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 36 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
2、mke2fs -j /dev/sdb5创建ext3文件系统
[root@localhost ~]# mke2fs -j /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
131648 inodes, 526120 blocks
26306 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=541065216
17 block groups
32768 blocks per group, 32768 fragments per group
7744 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Creating journal (16384 blocks): done （ext3是日志文件系统）
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 26 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
3、mke2fs -b 2048 /dev/sdb5创建块大小为2048
[root@localhost ~]# mke2fs -b 2048 /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=2048 (log=1)
Fragment size=2048 (log=1)
Stride=0 blocks, Stripe width=0 blocks
131560 inodes, 1052240 blocks
52612 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=538968064
65 block groups
16384 blocks per group, 16384 fragments per group
2024 inodes per group
Superblock backups stored on blocks:
16384, 49152, 81920, 114688, 147456, 409600, 442368, 802816
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 24 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
4、mke2fs -L MYSDB /dev/sdb5指定卷标为MYSDB
[root@localhost ~]# mke2fs -L MYSDB /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label=MYSDB
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
131648 inodes, 526120 blocks
26306 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=541065216
17 block groups
32768 blocks per group, 32768 fragments per group
7744 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 21 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
5、mke2fs -m 3 /dev/sdb5指定超级块所占比例内存
[root@localhost ~]# mke2fs -m 3 /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
131648 inodes, 526120 blocks
15783 blocks (3.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=541065216
17 block groups
32768 blocks per group, 32768 fragments per group
7744 inodes per group
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 23 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
6、mke2fs -i 4096 /dev/sdb5指定inode及block比例为1:4096
[root@localhost ~]# mke2fs -i 4096 /dev/sdb5
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
526320 inodes, 526120 blocks
26306 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=540801024
17 block groups
32752 blocks per group, 32752 fragments per group
30960 inodes per group
Superblock backups stored on blocks:
32752, 98256, 163760, 229264, 294768
Writing inode tables: done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 31 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]#
blkid /dev/sdb5查看设备文件的基本属性，关注UUID及TYPE、LABEL字段
[root@localhost ~]# blkid /dev/sdb5
/dev/sdb5: UUID="edc852aa-376d-411b-876a-0deb9f89b140" TYPE="ext2"
[root@localhost ~]#
e2label: 用于查看或定义卷标
e2label 设备文件 卷标: 设定卷标
[root@localhost ~]# e2label /dev/sdb5 HELLO
[root@localhost ~]# e2label /dev/sdb5
HELLO
[root@localhost ~]# blkid /dev/sdb5
/dev/sdb5: UUID="edc852aa-376d-411b-876a-0deb9f89b140" TYPE="ext2" LABEL="HELLO"
[root@localhost ~]#
tune2fs: 调整文件系统的相关属性
-j: 不损害原有数据，将ext2升级为ext3；
-L LABEL: 设定或修改卷标;
-m #: 调整预留百分比；
-r #: 指定预留块数；
-o: 设定默认挂载选项；
acl
-c #：指定挂载次数达到#次之后进行自检，0或-1表关闭此功能；
-i #: 每挂载使用多少天后进行自检；0或-1表示关闭此功能；
-l: 显示超级块中的信息；
1、une2fs -j /dev/sdb5无损升级为ext3
[root@localhost ~]# tune2fs -j /dev/sdb5
tune2fs 1.41.12 (17-May-2010)
Creating journal inode: done
This filesystem will be automatically checked every 31 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@localhost ~]# blkid /dev/sdb5
/dev/sdb5: LABEL="HELLO" UUID="edc852aa-376d-411b-876a-0deb9f89b140" SEC_TYPE="ext2" TYPE="ext3"
[root@localhost ~]#
2、tune2fs -l /dev/sdb5查看超级块信息
[root@localhost ~]# tune2fs -l /dev/sdb5
tune2fs 1.41.12 (17-May-2010)
Filesystem volume name: HELLO
Last mounted on: <not available>
Filesystem UUID: edc852aa-376d-411b-876a-0deb9f89b140
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype sparse_super large_file
Filesystem flags: signed_directory_hash
Default mount options: (none)
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 526320
Block count: 526120
Reserved block count: 26306
Free blocks: 476004
Free inodes: 526309
First block: 0
Block size: 4096
Fragment size: 4096
Reserved GDT blocks: 128
Blocks per group: 32752
Fragments per group: 32752
Inodes per group: 30960
Inode blocks per group: 1935
Filesystem created: Tue Feb 21 14:49:15 2017
Last mount time: n/a
Last write time: Tue Feb 21 15:41:16 2017
Mount count: 0
Maximum mount count: 31
Last checked: Tue Feb 21 14:49:15 2017
Check interval: 15552000 (6 months)
Next check after: Sun Aug 20 15:49:15 2017
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size: 256
Required extra isize: 28
Desired extra isize: 28
Journal inode: 8
Default directory hash: half_md4
Directory Hash Seed: 903d8d69-a548-4c82-955e-328a4025eaeb
Journal backup: inode blocks
[root@localhost ~]#
dumpe2fs: 显示文件系统属性信息
-h: 只显示超级块中的信息
[root@localhost ~]# dumpe2fs /dev/sdb5
dumpe2fs 1.41.12 (17-May-2010)
Filesystem volume name: HELLO
Last mounted on: <not available>
Filesystem UUID: edc852aa-376d-411b-876a-0deb9f89b140
Filesystem magic number: 0xEF53
Filesystem revision #: 1 (dynamic)
Filesystem features: has_journal ext_attr resize_inode dir_index filetype sparse_super large_file
Filesystem flags: signed_directory_hash
Default mount options: (none)
Filesystem state: clean
Errors behavior: Continue
Filesystem OS type: Linux
Inode count: 526320
Block count: 526120
Reserved block count: 26306
Free blocks: 476004
Free inodes: 526309
First block: 0
Block size: 4096
Fragment size: 4096
Reserved GDT blocks: 128
Blocks per group: 32752
Fragments per group: 32752
Inodes per group: 30960
Inode blocks per group: 1935
Filesystem created: Tue Feb 21 14:49:15 2017
Last mount time: n/a
Last write time: Tue Feb 21 15:41:16 2017
Mount count: 0
Maximum mount count: 31
Last checked: Tue Feb 21 14:49:15 2017
Check interval: 15552000 (6 months)
Next check after: Sun Aug 20 15:49:15 2017
Reserved blocks uid: 0 (user root)
Reserved blocks gid: 0 (group root)
First inode: 11
Inode size: 256
Required extra isize: 28
Desired extra isize: 28
Journal inode: 8
Default directory hash: half_md4
Directory Hash Seed: 903d8d69-a548-4c82-955e-328a4025eaeb
Journal backup: inode blocks
Journal features: (none)
Journal size: 64M
Journal length: 16384
Journal sequence: 0x00000001
Journal start: 0
（块组信息）
Group 0: (Blocks 0-32751)
Primary superblock at 0, Group descriptors at 1-1
Reserved GDT blocks at 2-129
Block bitmap at 130 (+130), Inode bitmap at 131 (+131)
Inode table at 132-2066 (+132)
30679 free blocks, 30949 free inodes, 2 directories
Free blocks: 2073-32751
Free inodes: 12-30960
Group 1: (Blocks 32752-65503)
Backup superblock at 32752, Group descriptors at 32753-32753
Reserved GDT blocks at 32754-32881
Block bitmap at 32882 (+130), Inode bitmap at 32883 (+131)
Inode table at 32884-34818 (+132)
30685 free blocks, 30960 free inodes, 0 directories
Free blocks: 34819-65503
Free inodes: 30961-61920
Group 2: (Blocks 65504-98255)
Block bitmap at 65504 (+0), Inode bitmap at 65505 (+1)
Inode table at 65506-67440 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 67441-98255
Free inodes: 61921-92880
Group 3: (Blocks 98256-131007)
Backup superblock at 98256, Group descriptors at 98257-98257
Reserved GDT blocks at 98258-98385
Block bitmap at 98386 (+130), Inode bitmap at 98387 (+131)
Inode table at 98388-100322 (+132)
30685 free blocks, 30960 free inodes, 0 directories
Free blocks: 100323-131007
Free inodes: 92881-123840
Group 4: (Blocks 131008-163759)
Block bitmap at 131008 (+0), Inode bitmap at 131009 (+1)
Inode table at 131010-132944 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 132945-163759
Free inodes: 123841-154800
Group 5: (Blocks 163760-196511)
Backup superblock at 163760, Group descriptors at 163761-163761
Reserved GDT blocks at 163762-163889
Block bitmap at 163890 (+130), Inode bitmap at 163891 (+131)
Inode table at 163892-165826 (+132)
30685 free blocks, 30960 free inodes, 0 directories
Free blocks: 165827-196511
Free inodes: 154801-185760
Group 6: (Blocks 196512-229263)
Block bitmap at 196512 (+0), Inode bitmap at 196513 (+1)
Inode table at 196514-198448 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 198449-229263
Free inodes: 185761-216720
Group 7: (Blocks 229264-262015)
Backup superblock at 229264, Group descriptors at 229265-229265
Reserved GDT blocks at 229266-229393
Block bitmap at 229394 (+130), Inode bitmap at 229395 (+131)
Inode table at 229396-231330 (+132)
30685 free blocks, 30960 free inodes, 0 directories
Free blocks: 231331-262015
Free inodes: 216721-247680
Group 8: (Blocks 262016-294767)
Block bitmap at 262016 (+0), Inode bitmap at 262017 (+1)
Inode table at 262018-263952 (+2)
14414 free blocks, 30960 free inodes, 0 directories
Free blocks: 280354-294767
Free inodes: 247681-278640
Group 9: (Blocks 294768-327519)
Backup superblock at 294768, Group descriptors at 294769-294769
Reserved GDT blocks at 294770-294897
Block bitmap at 294898 (+130), Inode bitmap at 294899 (+131)
Inode table at 294900-296834 (+132)
30685 free blocks, 30960 free inodes, 0 directories
Free blocks: 296835-327519
Free inodes: 278641-309600
Group 10: (Blocks 327520-360271)
Block bitmap at 327520 (+0), Inode bitmap at 327521 (+1)
Inode table at 327522-329456 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 329457-360271
Free inodes: 309601-340560
Group 11: (Blocks 360272-393023)
Block bitmap at 360272 (+0), Inode bitmap at 360273 (+1)
Inode table at 360274-362208 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 362209-393023
Free inodes: 340561-371520
Group 12: (Blocks 393024-425775)
Block bitmap at 393024 (+0), Inode bitmap at 393025 (+1)
Inode table at 393026-394960 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 394961-425775
Free inodes: 371521-402480
Group 13: (Blocks 425776-458527)
Block bitmap at 425776 (+0), Inode bitmap at 425777 (+1)
Inode table at 425778-427712 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 427713-458527
Free inodes: 402481-433440
Group 14: (Blocks 458528-491279)
Block bitmap at 458528 (+0), Inode bitmap at 458529 (+1)
Inode table at 458530-460464 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 460465-491279
Free inodes: 433441-464400
Group 15: (Blocks 491280-524031)
Block bitmap at 491280 (+0), Inode bitmap at 491281 (+1)
Inode table at 491282-493216 (+2)
30815 free blocks, 30960 free inodes, 0 directories
Free blocks: 493217-524031
Free inodes: 464401-495360
Group 16: (Blocks 524032-526119)
Block bitmap at 524032 (+0), Inode bitmap at 524033 (+1)
Inode table at 524034-525968 (+2)
151 free blocks, 30960 free inodes, 0 directories
Free blocks: 525969-526119
Free inodes: 495361-526320
[root@localhost ~]#
fsck: 检查并修复Linux文件系统（通用文件系统检查及修复）
-t FSTYPE: 指定文件系统类型
-a: 自动修复
[root@localhost ~]# fsck -a /dev/sdb5
fsck from util-linux-ng 2.17.2
HELLO: clean, 11/526320 files, 50116/526120 blocks
[root@localhost ~]#
e2fsck: 专用于修复ext2/ext3文件系统
-f: 强制检查；
-p: 自动修复；
[root@localhost ~]# e2fsck /dev/sdb5
e2fsck 1.41.12 (17-May-2010)
HELLO: clean, 11/526320 files, 50116/526120 blocks
[root@localhost ~]#
挂载：将新的文件系统关联至当前根文件系统
卸载：将某文件系统与当前根文件系统的关联关系预以移除；
mount：挂载
mount 设备 挂载点
设备：
设备文件：/dev/sda5
卷标：LABEL=“”
UUID： UUID=“”
挂载点：目录
要求：
1、此目录没有被其它进程使用；
2、目录得事先存在；
3、目录中的原有的文件将会暂时隐藏；
mount: 显示当前系统已经挂载的设备及挂载点
mount [options] [-o options] DEVICE MOUNT_POINT
-a: 表示挂载/etc/fstab文件中定义的所有文件系统
-n: 默认情况下，mount命令每挂载一个设备，都会把挂载的设备信息保存至/etc/mtab文件；使用—n选项意味着挂载设备时，不把信息写入此文件；
-t FSTYPE: 指定正在挂载设备上的文件系统的类型；不使用此选项时，mount会调用blkid命令获取对应文件系统的类型；
-r: 只读挂载，挂载光盘时常用此选项
-w: 读写挂载
-o: 指定额外的挂载选项，也即指定文件系统启用的属性；
remount: 重新挂载当前文件系统
ro: 挂载为只读
rw: 读写挂载
mount命令，可以挂载iso镜像；
mount DEVICE MOUNT_POINT
-o loop: 挂载本地回环设备
挂载完成后，要通过挂载点访问对应文件系统上的文件；
umount: 卸载某文件系统
umount 设备
umount 挂载点
卸载注意事项：
挂载的设备没有进程使用；
1、mount挂载设备/dev/sdb5 在目录/mnt/test/
[root@localhost ~]# blkid /dev/sdb5
/dev/sdb5: LABEL="HELLO" UUID="edc852aa-376d-411b-876a-0deb9f89b140" SEC_TYPE="ext2" TYPE="ext3"
[root@localhost ~]#
[root@localhost ~]#
[root@localhost ~]# mkdir /mnt/test
[root@localhost ~]# mount /dev/sdb5 /mnt/test/
[root@localhost ~]# ll /mnt/test/
total 16
drwx------. 2 root root 16384 Feb 21 14:49 lost+found
[root@localhost ~]#
2、umount卸载
[root@localhost ~]# umount /mnt/test/
[root@localhost ~]# ll /mnt/test/
total 0
[root@localhost ~]#
3、查看所有挂载设备
[root@localhost ~]# mount /dev/sdb5 /mnt/test/
[root@localhost ~]# mount
/dev/sda2 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
/dev/sda1 on /boot type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/sdb5 on /mnt/test type ext3 (rw)
[root@localhost ~]#
4、查看设备挂载信息
[root@localhost ~]# cat /etc/mtab
/dev/sda2 / ext4 rw 0 0
proc /proc proc rw 0 0
sysfs /sys sysfs rw 0 0
devpts /dev/pts devpts rw,gid=5,mode=620 0 0
tmpfs /dev/shm tmpfs rw,rootcontext="system_u:object_r:tmpfs_t:s0" 0 0
/dev/sda1 /boot ext4 rw 0 0
none /proc/sys/fs/binfmt_misc binfmt_misc rw 0 0
/dev/sdb5 /mnt/test ext3 rw 0 0
[root@localhost ~]#
5、只读方式重新挂载
[root@localhost ~]# mount -o remount,ro /dev/sdb5
[root@localhost ~]# mount
/dev/sda2 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw,gid=5,mode=620)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
/dev/sda1 on /boot type ext4 (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
/dev/sdb5 on /mnt/test type ext3 (ro)
