鸟哥的linux私房菜学习笔记《十一》磁盘与文件系统（block与inode）

磁盘的组成主要有：



主分区和扩展分区：



super block、inode、block



文件系统一开始就将inode与block规划好了，除非重新格式化，否则inode与block固定后就不在变动

文件系统最前面有一个启动扇区，这个启动扇区可以安装引导装载程序。

数据块）数据块：

在Ext2文件系统中所支持的block大小有1KB，2KB及4KB三种而已。



inodetable（inode表格）

inode记录的文件数据至少有：







super block（超级块）：





block bitmap（block对照表）、inode bitmap（inode对照表）



dumpe2fs查询超级块的信息

参数：

-b：列出保留为坏道的部分

-h：仅列出superblock的数据，不会列出其他的区段内容

[root@CentOS kevin]# dumpe2fs /dev/sda1
dumpe2fs 1.41.12 (17-May-2010)
Filesystem volume name:   <none>
Last mounted on:          /boot
Filesystem UUID:          210195dc-73eb-4dc8-be3e-db36b147c314
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super huge_file uninit_bg dir_nlink extra_isize
Filesystem flags:         signed_directory_hash
Default mount options:    user_xattr acl
Filesystem state:         clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              51200
Block count:              204800
Reserved block count:     10240
Free blocks:              170154
Free inodes:              51162
First block:              1
Block size:               1024
Fragment size:            1024
Reserved GDT blocks:      256
Blocks per group:         8192
Fragments per group:      8192
Inodes per group:         2048
Inode blocks per group:   256
Flex block group size:    16
Filesystem created:       Wed Mar  1 16:03:23 2017
Last mount time:          Mon Mar  6 00:22:57 2017
Last write time:          Mon Mar  6 00:22:57 2017
Mount count:              11
Maximum mount count:      -1
Last checked:             Wed Mar  1 16:03:23 2017
Check interval:           0 (<none>)
Lifetime writes:          48 MB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:           128
Journal inode:            8
Default directory hash:   half_md4
Directory Hash Seed:      4f4c0f86-b819-4859-a959-67ebacd82557
Journal backup:           inode blocks
Journal features:         (none)
Journal size:             4096k
Journal length:           4096
Journal sequence:         0x00000024
Journal start:            0

Group 0: (Blocks 1-8192) [ITABLE_ZEROED]
Checksum 0xf843, unused inodes 2010
Primary superblock at 1, Group descriptors at 2-2
Reserved GDT blocks at 3-258
Block bitmap at 259 (+258), Inode bitmap at 275 (+274)
Inode table at 291-546 (+290)
3785 free blocks, 2010 free inodes, 6 directories, 2010 unused inodes
Free blocks: 4408-8192
Free inodes: 39-2048
Group 1: (Blocks 8193-16384) [INODE_UNINIT, ITABLE_ZEROED]
Checksum 0x6273, unused inodes 2048
Backup superblock at 8193, Group descriptors at 8194-8194
Reserved GDT blocks at 8195-8450
Block bitmap at 260, Inode bitmap at 276
Inode table at 547-802
1296 free blocks, 2048 free inodes, 0 directories, 2048 unused inodes
Free blocks: 9016-10240, 12218-12288
Free inodes: 2049-4096
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