I think my file system has been damaged. Instead of block 1, I want to use block n as superblock. How do I find out an alternative superblock location under Linux?
Q. I need to find out inode size of my ext3 file system for recovery purpose. How can I find the inode size of an ext2/ext3 filesystem?
A. You need to use tune2fs command, which allows the system administrator to adjust various tunable filesystem parameters on Linux ext2/ext3 filesystems.
Find the inode size of the filesystem
The -l option lists the inode size of the filesystem. Using the same option, other information of the filesystem superblock can also be seen. The superblock contains information about the filesystem, such as the number of free blocks available, and the number of mounts, that may be useful for tuning purposes.
# sudo tune2fs -l /dev/sda2
tune2fs 1.40.2 (12-Jul-2007) Filesystem volume name:
Last mounted on: Filesystem UUID: 8c2da865-13f4-47a2-9c92-2f31738469e8 Filesystem magic number: 0xEF53 Filesystem revision #: 1 (dynamic) Filesystem features: has_journal resize_inode dir_index filetype needs_recovery 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: 12222464 Block count: 24412775 Reserved block count: 1220638 Free blocks: 17464715 Free inodes: 12055081 First block: 0 Block size: 4096 Fragment size: 4096 Reserved GDT blocks: 1018 Blocks per group: 32768 Fragments per group: 32768 Inodes per group: 16384 Inode blocks per group: 512 Filesystem created: Sat Oct 6 04:51:23 2007 Last mount time: Fri Nov 9 08:07:04 2007 Last write time: Fri Nov 9 08:07:04 2007 Mount count: 12 Maximum mount count: 32 Last checked: Mon Nov 5 13:33:36 2007 Check interval: 15552000 (6 months) Next check after: Sat May 3 13:33:36 2008 Reserved blocks uid: 0 (user root) Reserved blocks gid: 0 (group root) First inode: 11 Inode size: 128 Journal inode: 8 First orphan inode: 1163400 Default directory hash: tea Directory Hash Seed: bcaf359b-11c2-4c1a-8823-92be72c09ac4 Journal backup: inode blocks
To find the inode size, enter:
# sudo tune2fs -l /dev/sda2 | grep Inode
Inode count: 12222464 Inodes per group: 16384 Inode blocks per group: 512 Inode size: 128