EXT3 文件系统
block size=1024时，单个文件最大支持16GB block size=4096时，单个文件最大支持4TB （官方说是2TB）
计算方式： 表 1. 各种数据块对应的文件寻址范围
块大小 | 直接寻址 | 间接寻址 | 二次间接寻址 | 三次间接寻址 |
|---|---|---|---|---|
1024 | 12KB | 268KB | 64.26MB | 16.06GB |
2048 | 24KB | 1.02MB | 513.02MB | 265.5GB |
4096 | 48KB | 4.04MB | 4GB | ~ 4TB |
详细资料查看：
http://zh.wikipedia.org/zh-cn/Ext3
如何查看某分区文件系统信息：
[root@fedora13 ~]# df -lh Filesystem Size Used Avail Use% Mounted on /dev/mapper/vg_fedora13-LogVol00 92G 4.7G 82G 6% / tmpfs 1007M 1.9M 1005M 1% /dev/shm /dev/sda1 485M 60M 400M 14% /boot /dev/mapper/vg_fedora13-LogVol01 202G 43G 149G 23% /home /home/wuhaoshu/os/Fedora-13-i386-DVD.iso 3.1G 3.1G 0 100% /mnt/cdrom [root@fedora13 ~]# tune2fs -l /dev/mapper/vg_fedora13-LogVol01 tune2fs 1.41.10 (10-Feb-2009) Filesystem volume name: <none> Last mounted on: <not available> Filesystem UUID: 435579c0-0af8-44fb-8ffe-2b67790729ba Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal ext_attr resize_inode dir_index filetype needs_recovery sparse_super large_file Filesystem flags: signed_directory_hash Default mount options: user_xattr acl Filesystem state: clean Errors behavior: Continue Filesystem OS type: Linux Inode count: 13443072 Block count: 53755904 Reserved block count: 2687795 Free blocks: 42509664 Free inodes: 13426199 First block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 1011 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 8192 Inode blocks per group: 512 Filesystem created: Mon Aug 9 12:54:11 2010 Last mount time: Wed Aug 25 09:54:31 2010 Last write time: Wed Aug 25 09:54:31 2010 Mount count: 28 Maximum mount count: -1 Last checked: Mon Aug 9 12:54:11 2010 Check interval: 0 (<none>) 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: 9ee3f59d-ad94-48ab-a183-1f4eaac37285 Journal backup: inode blocks [root@fedora13 ~]#
