SEU%20COSC513%20Presentation%20Linux%20File%20Management%20Systems

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SEU COSC513 PresentationLinux File Management
Systems

• Student Bo Ling
• Instructor Prof. Mort Anvari
• Quarter Spring, 2001

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Introduction

• File management systems

• Linux

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File System Architecture
User Program
Pile Sequential Indexed sequential Indexed Hashed
Logical I/O
Basic I/O Supervisor
Basic File System
Disk Device Driver Tape Device Driver
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Server Market Share
1996 1999 2003
Windows 23.8 36.8 44.5
Linux 6.0 23.8 36.7
Netware 29.9 18.0 9.5
Unix 18.6 14.8 8.9
Source IDC, 2000
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Linux File System History

• Minix filesystem
• Virtual File System (VFS)
• Extended filesystem
• Second extended filesystem (Ext2fs)
• Xia filesystem

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Features of Different File Systems
MinixFS Ext FS Ext2 FS Xia FS
Max FS size 64 MB 2 GB 4 TB 2 GB
Max File size 64 MB 2 GB 2 GB 64 MB
Max file name 16/30 255 255 248
Extensible No No Yes No
Var. block size No No Yes No
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File System Supported in Linux

• Second extended filesystem
• Extended filesystem
• Minix filesystem
• Xia filesystem
• Network File System
• UMSDOS filesystem
• MS-DOS filesystem
• HPFS filesystem

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(cont.)

• /proc filesystem
• ISO 9660 filesystem
• Xenix filesystem
• System V filesystem
• Coherent filesystem
• Novell filesystem
• SMB filesystem

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User process
System call
System calls interface
VFS
Linux Kernel
DOS FS
Ext FS
Ext2 FS
Minix
Buffer cache
Device drivers
I/O request
Hardware
Disk Controller
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Ext2fs Features

• Max filesystem size to 4 TB.
• Max file name size 255 char, extendable to 1012
  char.
• File attributes
• Preallocation techniqu
• Fast symbolic links.
• Keeps track of the filesystem status.

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Ext2fs Features (cont.)

• buffer cache management
• Block groups

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Second Extended FS Performance
Char write (KB/s) Block Write (KB/s) Rewrite (KB/s) Char Read (KB/s) Block Read (KB/s)
Unix BSD 710 684 401 721 888
Ext2 fs 452 1237 536 397 1033
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REFERENCE

• http//www.linux-mag.com/backissues.html
• http//step.polymtl.ca/ldd/ext2fs/ext2fs_1.html
• http//e2fsprogs.sourceforge.net/ext2intro.html
• http//aeschi.ch.eu.org/efs/