Linux 18 - Maintain the Integrity of the Filesystem

- check integrity
- monitor free space inodes
- repair simple problems

df ( disk free )

1) By default it will show in kilobytes
2) -h stands for human-readable format
3) shows inodes, used and free

Inodes
–every file on your computer takes an INODE – a bookmark
–it's how a file is found
–maximum files 459637 files can be created on /dev/sdb1
–they are created when a partition is created
–an inode takes up space
–there is one per file
–can be a problem with a fileserver
–makefs is good at estimateing at req inodes

du ( disk usage of individual folders )

 

1) Default size is in blocks
2) -h is human readable form
3) --summarize will not go recursive
This command is sorta like FolderSize for Windows

fsck ( check filesystem )

1) unmount /dev/sdb1

2) fsck /dev/sdb1

3) fsck -t ext3 /dev/sdb1

4) e2fsck /dev/sdb1

Commands 2,3,4 are doing the same things.

xfs_check & xfs_repair

reiserfscheck

1) mkfs -t reiserfs /dev/sdb1

2) reiserfsck /dev/sdb1

 

e2fsck, fsck.ext2, fsck -ext2

Repair simple problems

- most of the tools are available only for ext filesystems

debugfs

recovering a file

1) create a test file

2) use debugfs -w /dev/sdb1

3) delete the file

4) issue lsdel to list deleted files

5) undelete

dumpe2fs
dump ext2/ext3/ext4 filesystem information.

dumpe2fs on a ext2 filesystem has not “has_journal” flag set

add the journal to ext2

adding the journal uses the -O in the tune2fs program

to remove the feature use the carret symbol “^”

xfs_info

xfs dump metainfo dump on the xfs fs