1. Linux File Systems Presented by: Lloyd Brown, James Frazee, & Travis Wertz

2. File System Capabilities File types Permissions

3. File Types Regular Files Directories Links Symbolic Hard

4. Permissions Old Unix-style Standard Permissions: Universal User, Group, Others Example: user@host~$ ls -lh procmail.log -rw------- 1 lbrown lbrown 47K Mar 30 14:17 procmail.log

5. Permissions Access Control List (ACL) Allows arbitrary users/groups to be given permissions to files Example: user@host# getfacl www # file: www # owner: root # group: clusterstat user::rwx user:36:r-x group::rwx group:clusterstat:rwx group:clusterstat_ro:r-x mask::rwx other::--- default:user::rwx default:user:36:r-x default:group::rwx default:group:clusterstat:rwx default:group:clusterstat_ro:r-x default:mask::rwx default:other::---

6. Virtual File Systems Inodes Dentrys Superblocks

7. Inode I(ndex)Node Describes location of each file, directory, or link within every FS Identified by a tuple containing unique number

8. Dentry Directory Entry Used to map file descriptors to inodes Contains name of file or directory File descriptor points to a dentry, which points to inode.

9. Dentry Example /home/chris/home/jim / home /home/chris/foo/home/chris/bar/home/chris/txt Dentry Pointer

10. Superblock When FS is mounted, contents are attached to primary directory tree Superblock contains information about mounted FS Type Root inode location Items that protect integrity Created by kernel Resides in memory

11. Specific Types General File Systems Network File Systems Special Purpose File Systems

12. General File Systems Ext 2/3 ReiserFS JFS XFS

13. Network File Systems NFS SMB/CIFS

14. Memory File Systems ProcFS TmpFS SysFS RamFS