The LINUX Operating System

• By Cathy Thiaw• ID # 89261

• COSC 513 Lecturer: M. Anvari

• SEU ‘99 Summer Term

What’s Linux?

• an OS initially created by Linus Torvalds (Finland) and a team working over the Internet;

• developed from MINIX, a small Unix system;

• An open and free operating system, adaptable to meet individuals needs;

Linux Features

• Multitasking

• Virtual memory

• Shared libraries

• Multi_users capabilities

• X-windows systems

• Run most Unix programs

Linux Features

• Advanced networking capabilities: LAN or WAN setting, different types of protocols, fast TCP/IP drivers

• Support for Macintosh, Windows, NT, Novell, OS/2

• Server or Client

Resource Management

• Use of semaphores

• 1 process at a time can access to some resource

• The semaphore data structure includes a count of number of processes that wish to use a resource, a waking parameter (number of processes waiting to be woken up), and a wait queue.

Processes on Linux

• Interprocess-communications: Unix -liked mechanisms of signals, pipes and semaphores, shared memory...

• Relationships parent / child process

• Most process has virtual memory

Processes on Linux

• Max number of processes in the system: 512

• State process:– *running– *waiting: interruptible or uninterruptible – -*stopped– *zombie: dead process

Security

• Security on Linux is comparable with most Unix system

• Security tools : firewalls, packets filtering, encryption, kerberos… are available

• Monitoring (logs) and audit of logon activities, resource utilization …available

Comparison with other OS

• Windows NT

• BSDI

• Solaris 7.0

Network Inter-operability

• Runnable foreign libraries:• -Linux2.2: Windows 3.*‑98 Mac (Executor), SCO and some other Intel based SysV's(iBCS)

• NT4: MAC(Executor),dos, windows 3.1/W32

• BSDI: DOS, support for Linux in development

• Solaris: Macintosh,Windows 3.1

Network and Inter-operability

• Mountable filesystems• Linux 2.2: FAT, FS read-only,HPFS read-only (OS/2), iso9660 (CDROM), minix, NTFS (read-only), HFS (MacOS)…

• NT4: FAT, NTFS, iso9660• BSDI: iso9660• Solaris: UFS, FAT (dos, windows),UFS, iso9660…

OS Convenience

• Bug fix and other updates:

• Linux2.2.: Freely download able• NT4: not free• BSDI: Some minor, updates/bugfixes can be downloaded freely.

• Solaris7.0: not free