RONG LIU (Operating System Comparison)

Introduction(1) What is Linux? The free UNIX written from scratch by Linus Torvalds, assistance from a loosely-knit team of hackers from across the internet. A modern, fully fledged UNIX: true multitasking, virtual memory, shared libraries, demand loading, shared, copy-on-write executables, proper memory management, and TCP/IP networking.

Introduction(2) History of Unix In April, 1969, Ken Thompson, Brian Kernighan and Dennis Ritchie sketched out an operating system that would meet Bell Labs' needs, soon become Unix. In 1973, UNIX, was rewritten in C as Version 4 by Dennis Ritchie and Brian Kernighan. Two major hot-beds of Unix development were at the University of California, Berkeley, which later became BSD (Berkeley Software Distribution), and M.I.T., which eventually gave us the Free Software Foundation and the GNU project, and the X Window System.

Introduction(2) (Cont...) History of Unix Unix today has two major versions: System V (or SVR4 from Unix System) and BSD (Berkeley Software Distribution). UNIX (upper case) is a trademark of The Open Group. Unix refers to Unix versions in general, regardless of the source; usually it is simply referred to as SVR4 or BSD 4.4.

Linux operating system overview Memory Management: –Page Allocation –The Linux Page Cache –The Swap Cache Processes The Linux Networking Linux PCI Initialization

Processes Processes have following states: Running Waiting Stopped Zombie

The Linux Networking Linux supports the following socket address families or domains: UNIX -- Unix domain sockets. INET -- communications via TCP/IP. AX25 -- Amateur radio X25. IPX -- Novell IPX AppleTalk -- AppleTalk DDP X25 -- X25

Linux PCI Initialization PCI Device Driver A. builds a linked list of data structures describing the topology of the system.  B. numbers all of the bridges that it finds. PCI BIOS provides the services described in bib-pci-bios-specification. PCI Fixup tidies up the system specific loose ends of PCI initialization.

Unix operating system overview OS Structure File System Directories Structure Common Control Keys Unix Shells

Unix OS Structure Hardware Kernel Shell Editors, Private User programs Compiler Components Compiler

Unix file system

Unix Directories Structure 1). Every directory and file is listed in its parent directory. 2). Each file assigned inode number, an inode is a special file designed to be read by the kernel to learn the information about each file. 3). The system does not require any particular structure for the data in the file itself. i.e. It can be ASCII, binary or a combination. 4). There's no header, trailer, label information or EOF character as part of the file.

- C: Standard interrupt key; -U: The key deletes the entire line; -H: Use to erase the characters; -W: Deletes the word you are entering; -R: Moves cursor to next line; -D: Logs out from shell prompt; -S: Stops terminal accepting input; -Q: Starts terminal accepting input. Unix Common Control Keys CONTROL

Unix Shells The shell sits between you and the operating system, acting as a command interpreter. The common shells as follow: 1). Bourne shell, sh($) was the original shell. 2). C shell prompt is %. 3). Korn shell, ksh has nearly all the features of Bourne Shell, maximixes execution speed of scripts.

Linux compares with Unix The File systems Shared Virtual Memory Inter-Process Communication Identifiers Executing Programs EXT2 File System Similarity of Linux and Unix

Compare Linux2.2 with Solaris7.0(1) OS convenience Bugfixes and other updates Linux 2.2Solaris 7.0 Freely download able, and available on CD. Both a stable and a bleeding-edge version is available. Some (all???) minor updates/bugfixes can be downloaded freely. Subscription customers get's major upgrades on CD. Run a GUI app on one machine Diaplay it on another. yes Virus no

Compare Linux2.2 with Solaris7.0(2) OS Single Unix Specification v.1 Single Unix Specification v.1 (UNIX95) Linux 2.2Solaris 7.0 Single Unix Specification v.2 Single Unix Specification v.2 (UNIX98) yes Address space no yes Multiple CPU'sSMP up to 16 CPU's, much improved performance in comparison to 2.0.*, clusteringclustering SMP on both Sparc and Intel 64 CPU's on sparc Max. file size 2 GB (ext2)1 TB (on UltraSparc) Max. file system size16 TB (ext2)1 TB (on UltraSparc) OS Flavor Designed from scratch to be Posix and now Unix98 compliant. Has some backwards SysV R4

Compare Linux2.2 with Solaris7.0(3) OS( Con.) Linux 2.2Solaris 7.0 Memory protection Yes POSIX.1 certification A posix.1 certified Linux 2.0.* kernel is available from Unifix. The main kernel is designed to be posix complient, but haven't been certified.Unifix Yes Threadsposix c XPG4 base 95 no Yes

Compare Linux2.2 with Solaris7.0(4) Provider Linux 2.2Solaris 7.0 Manufactor Developed, programmed and maintained by a big group of people from all over the world. Sun Microsystems Inc. 901 San Antonio Road Palo Alto CA USA Pricing free pay-ware or 2 year subscriptions2 year subscriptions

Compare Linux2.2 with Solaris7.0(5) Hardware Linux 2.2Solaris 7.0 Peripherals Most PC hardware. All current Sparc peripherals, some PC peripherals.some PC peripherals. Platforms PC >= 386, Digital Alpha, Sparc, UltraSparc, PPC, StrongARM More are in developmentDigital Alpha Sparc and PC >= 386

Reference: 1)."Linux at work ( building Strategic Applications for Business)" by Marcus Concalves. 2). "Peter Norton's Complete Guide to Linux" by Peter Norton and Arthur Grifficth. 3). “UNIX System V(Practical Guide) “by Mark G. Sobell. 4). “Operating Systems” by William Stallings. 5). Web page at 6). Web page at 7). Web page at