Distributed File Systems Part I. Issues in Centralized File Systems

Save this PDF as:
Size: px
Start display at page:

Download "Distributed File Systems Part I. Issues in Centralized File Systems"

Transcription

1 Distributed File Systems Part I Daniel A. Menascé File Naming Issues in Centralized File Systems c:\courses\cs571\procs.ps (MS-DOS) /usr/menasce/courses/cs571/processes.ps (UNIX) File Structure bitstream or bytestream record oriented (record = key + data) indexed (e.g., B*-trees (IBM VSAM) ) 1

2 B*-Tree Files a > b > index nodes leaf nodes Issues in Centralized File Systems File Types text (e.g., ASCII) binary (e.g., executables, images, etc.) Directory Structures flat hierarchical (tree) graph 2

3 hierarchical Directories graph menasce menasce courses papers courses papers CS571 INFS601 CS571 INFS601 intro.ps procs.ps intro.ps procs.ps intro.ps procs.ps grinfs601.xls grcs571.xls grinfs601.xls grcs571.xls hierarchical Directories menasce courses papers CS571 INFS601 ~menasce/courses/cs571/intro.ps ~menasce/courses/infs601/intro.ps intro.ps procs.ps grcs571.xls intro.ps procs.ps grinfs601.xls 3

4 Directories graph menasce ~menasce/courses/cs571/intro.ps ~menasce/courses/infs601/intro.ps courses papers CS571 INFS601 intro.ps procs.ps grcs571.xls grinfs601.xls Issues in Centralized File Systems Allocation of File to Disk Blocks contiguous linked indexed i-node (UNIX) 4

5 Contiguous Allocation of File to Disk Blocks start address = 101 no. of used blocks = 3 last reserved block = 150 simple mapping bad use of disk space hard to expand if maximum allocation is exceeded Linked Allocation of File to Disk Blocks first block address = 154 last block address = 237 number of blocks = 3 good use of disk space bad performance for direct access (e.g. reading the k-thblock requires reading k blocks) directory info 5

6 Indexed Allocation of File to Disk Blocks (index in main memory) disk efficient direct access good use of disk space inadequate for very large files (very large index). UNIX I-node item type (e.g., file, directory) item size in bytes time the file s inode was last modified time the file s contents was last modified time the file was last accessed reference count: number of file names file s owner (a UID) file s group (a GID) file s mode bits (r,w,x) Pointers to Data on Disk 6

7 UNIX Directories... foo bar notes doc notes and doc are the same file I-node Allocation of File to Disk Blocks file attributes SIP= single indirect pointer DIP= double indirect pointer TIP= triple indirect pointer SIP DIP TIP I-node 7

8 I-node Allocation of File to Disk Blocks Efficient access to data blocks of small (from i-node), medium (from single indirect blocks), large (from double indirect blocks), and huge (from triple indirect block) files. Maximum file size (assuming 512 byte blocks and 4 bytes per pointer): ( **2+128***3) * GByte Security in Centralized Systems What is security? Storing protection data. UNIX File Protection. Authentication methods. Users, Groups, and the superuser. 8

9 What Is Security? Confidentiality: protecting information from being read or copied by unauthorized users. Data Integrity: protecting information from being deleted or altered without permission. Availability: avoiding denial of service. Access Control: controlling who has access to the system. Accountability: keeping track of unauthorized accesses on an audit trail. Storing Protection Data SeCurity Protection Matrix Access Control Lists Capabilities usr1 usr n file 1 file 2 file m rw r rwx - rw - 9

10 Access Control Lists and Capabilities usr1 usr n file 1 file 2 file m rw r rwx - rw - capabilities: list of objects and access rights per user. access control list: list of users and access rights per object. UNIX Protection Model usr1 usr n file 1 file 2 file m rw r rwx - rw - access control list: list of users and access rights per object. UNIX implements a coarse grain version of ACLs. Users are divided into three groups: - owner - group - world Protection bits (r,w,x) are associated with each group. 10

11 Protection Bits for Files drwx--s--- 2 menasce 512 Nov 4 13:49 grades/ -rw-rw-r-- 1 menasce 684 Nov 4 13:48 project_ideas -rw menasce 509 Nov 4 13:48 student_mail -rw-r--r-- 1 menasce 3063 Nov 4 13:49 syllabus other s rights group rights owner rights entry type (- file; d directory) Authentication Methods Something that you know: password. Something that you have: a card key. Something that you are: fingerprint Combination: card key and password card key and weight 11

12 Passwords Passwords are stored in password files (/etc/passwd in UNIX) in an encrypted form (one-way encryption). Users should select hard to crack passwords: Use combinations of lower and upper case characters, punctuation signs (!$#?;:), and numbers. Good password: A$1c;:mE Bad password: sunshine Easy to remember: base password on a phrase. Change passwords regularly Users, User IDs and the Superuser Every user in UNIX has a username and a user identifier (UID) which is a number. Common users in UNIX systems: root: superuser performs accounting and low-level functions. daemon: handles network aspects agent: handles guest: for visitors ftp: for anonymous ftp. 12

13 Groups and Group Identifiers Every UNIX user belongs to one or more groups. Groups have a group name and a group ID (GID). Each user belongs to the primary group stored in the /etc/passwd file All groups are listed in the /etc/group file in UNIX Groups and Group Identifiers peter student group (gid 40) root john mary susan jill admin group (gid 0) users group (gid 104) ftp ftp group (gid 10) 13

14 The Superuser Every UNIX system has a special user with UI = 0 and usually called root. root is used by the OS to accomplish its basic functions root has access to all system resources! More than one user can be the superuser (they just need to have UID = 0). The superuser is the main security weakness in UNIX. Distributed File Systems File Service Interface: - upload/download model client get file put file server - entire files are retrieved from the server, and accessed at the client. - once the client is done, the file is stored back at the server. - typical of mass storage systems: e.g. Unitree. 14

15 Distributed File Systems File Service Interface: - remote access model client read block write block server - only the needed blocks of files are retrieved from the server. - once the client is done with a block, it is written back to the server. - example: NFS Distributed File Systems: directory service interface root at client 1 file server 1: A A D B C B C E F file server 2: D A root at client 2 D E F B C E F 15

16 Distributed File Systems: directory service interface root at client 1 file server 1: A A D B C B C E F file server 2: D A root at client 2 D E F B C E F Distributed File Systems: naming Location transparency: the path name does not reveal the file location. e.g.: /servera/dir1/dir2/x does not say where the server is located. Location independence: files can be moved and all references to them continue to be valid. e.g.: /servera/dir1/dir2/x is not location independent. 16

17 Distributed File Systems: two-level naming Symbolic Names: human readable. e.g.: /courses/slides/files.ps Binary names: machine readable names. Easier to manipulate. e.g.: UNIX i-node, or server IP address:i-node number Symbolic to binary name mapping may be one to many in a distributed system (file replication). Semantics of File Sharing UNIX semantics: used in centralized systems. - a read that follows a write sees the value written by the write. write x to block a read block a t1 t2 time x x x a a a get x 17

18 Semantics of File Sharing UNIX semantics: - a read that follows two writes in quick succession sees the result of the last write. write x to block a write x to block a read block a t1 t2 t3 get x x x x x x Semantics of File Sharing Issues in Distributed File Systems Single File Server - No client caching - easy to implement UNIX semantics Client File Caching - improves performance by decreasing demand at the server - updates to the cached file are not seen by other clients. 18

19 Semantics of File Sharing Session Semantics: (relaxed semantics) - changes to an open file are only visible to the process that modified the file. - when the file is closed, changes are visible to other processes closed file is sent back to the server. Semantics of File Sharing Session Semantics: - what if two or more clients are caching and modifying a file? final result depends on who closes last use an arbitrary rule to decide who wins. - file pointer sharing not possible when a process and its children run on different machines 19

20 Semantics of File Sharing No File Updates Semantics: - files are never updated. - allowed file operations: CREATE and READ. - files are atomically replaced in the directory. - Problem: what if two clients want to replace a file at the same time? take the last one or use any nondeterministic rule. Semantics of File Sharing Transaction Semantics: - all file changes are delimited by a Begin and End transaction. - all file requests within the transaction are carried out in order. - the complete transaction is either carried out completely or not at all (atomicity). 20

21 Semantics of File Sharing UNIX Semantics every operation is instantly visible to others Session Semantics no changes visible until file is closed. No Updates Semantics no file updates are allowed. Transactions atomic updates. 21

COS 318: Operating Systems. File Layout and Directories. Topics. File System Components. Steps to Open A File

COS 318: Operating Systems. File Layout and Directories. Topics. File System Components. Steps to Open A File Topics COS 318: Operating Systems File Layout and Directories File system structure Disk allocation and i-nodes Directory and link implementations Physical layout for performance 2 File System Components

More information

Operating Systems: Internals and Design Principles. Chapter 12 File Management Seventh Edition By William Stallings

Operating Systems: Internals and Design Principles. Chapter 12 File Management Seventh Edition By William Stallings Operating Systems: Internals and Design Principles Chapter 12 File Management Seventh Edition By William Stallings Operating Systems: Internals and Design Principles If there is one singular characteristic

More information

Chapter 11 Distributed File Systems. Distributed File Systems

Chapter 11 Distributed File Systems. Distributed File Systems Chapter 11 Distributed File Systems Introduction Case studies NFS Coda 1 Distributed File Systems A distributed file system enables clients to access files stored on one or more remote file servers A file

More information

CHAPTER 17: File Management

CHAPTER 17: File Management CHAPTER 17: File Management The Architecture of Computer Hardware, Systems Software & Networking: An Information Technology Approach 4th Edition, Irv Englander John Wiley and Sons 2010 PowerPoint slides

More information

Allion Ingrasys Europe. NAStorage. Security policy under a UNIX/LINUX environment. Version 2.01

Allion Ingrasys Europe. NAStorage. Security policy under a UNIX/LINUX environment. Version 2.01 Allion Ingrasys Europe NAStorage Security policy under a UNIX/LINUX environment Version 2.01 Security policy under a UNIX/LINUX environment Start Enabling a Unix/Linux Network (NFS Protocol) Adding a UNIX

More information

Chapter 12 File Management

Chapter 12 File Management Operating Systems: Internals and Design Principles Chapter 12 File Management Eighth Edition By William Stallings Files Data collections created by users The File System is one of the most important parts

More information

COSC 6374 Parallel Computation. Parallel I/O (I) I/O basics. Concept of a clusters

COSC 6374 Parallel Computation. Parallel I/O (I) I/O basics. Concept of a clusters COSC 6374 Parallel I/O (I) I/O basics Fall 2012 Concept of a clusters Processor 1 local disks Compute node message passing network administrative network Memory Processor 2 Network card 1 Network card

More information

NAStorage. Administrator Guide. Security Policy Of NAStorage Under UNIX/LINUX Environment

NAStorage. Administrator Guide. Security Policy Of NAStorage Under UNIX/LINUX Environment NAStorage Administrator Guide Security Policy Of NAStorage Under UNIX/LINUX Environment Version 1.00 10/01/2002 Prepared by: Leon Hsu TS Engineer Ingrasys Technology Inc. E-mail: support@ingrasys.com UNIX/LINUX

More information

Chapter 7: Unix Security. Chapter 7: 1

Chapter 7: Unix Security. Chapter 7: 1 Chapter 7: Unix Security Chapter 7: 1 Objectives Understand the security features provided by a typical operating system. Introduce the basic Unix security model. See how general security principles are

More information

Distributed File Systems

Distributed File Systems Distributed File Systems File Characteristics From Andrew File System work: most files are small transfer files rather than disk blocks? reading more common than writing most access is sequential most

More information

Distributed File Systems. NFS Architecture (1)

Distributed File Systems. NFS Architecture (1) COP 6611 Advanced Operating System Distributed File Systems Chi Zhang czhang@cs.fiu.edu NFS Architecture (1) a) The remote access model. (like NFS) b) The upload/download model (like FTP) 2 1 NFS Architecture

More information

CIS 551 / TCOM 401 Computer and Network Security

CIS 551 / TCOM 401 Computer and Network Security CIS 551 / TCOM 401 Computer and Network Security Spring 2007 Lecture 3 1/18/07 CIS/TCOM 551 1 Announcements Email project groups to Jeff (vaughan2 AT seas.upenn.edu) by Jan. 25 Start your projects early!

More information

We mean.network File System

We mean.network File System We mean.network File System Introduction: Remote File-systems When networking became widely available users wanting to share files had to log in across the net to a central machine This central machine

More information

OPERATING SYSTEMS FILE SYSTEMS

OPERATING SYSTEMS FILE SYSTEMS OPERATING SYSTEMS FILE SYSTEMS Jerry Breecher 10: File Systems 1 FILE SYSTEMS This material covers Silberschatz Chapters 10 and 11. File System Interface The user level (more visible) portion of the file

More information

Chapter 13 File and Database Systems

Chapter 13 File and Database Systems Chapter 13 File and Database Systems Outline 13.1 Introduction 13.2 Data Hierarchy 13.3 Files 13.4 File Systems 13.4.1 Directories 13.4. Metadata 13.4. Mounting 13.5 File Organization 13.6 File Allocation

More information

Chapter 13 File and Database Systems

Chapter 13 File and Database Systems Chapter 13 File and Database Systems Outline 13.1 Introduction 13.2 Data Hierarchy 13.3 Files 13.4 File Systems 13.4.1 Directories 13.4. Metadata 13.4. Mounting 13.5 File Organization 13.6 File Allocation

More information

File System Management

File System Management Lecture 7: Storage Management File System Management Contents Non volatile memory Tape, HDD, SSD Files & File System Interface Directories & their Organization File System Implementation Disk Space Allocation

More information

Secure data storage. André Zúquete Security 1

Secure data storage. André Zúquete Security 1 Secure data storage André Zúquete Security 1 Problems (1/3) ( The classical file system protection is limited Physical protection assumptions Physical confinement of storage devices Logical protection

More information

File Management. COMP3231 Operating Systems. Kevin Elphinstone. Tanenbaum, Chapter 4

File Management. COMP3231 Operating Systems. Kevin Elphinstone. Tanenbaum, Chapter 4 File Management Tanenbaum, Chapter 4 COMP3231 Operating Systems Kevin Elphinstone 1 Outline Files and directories from the programmer (and user) perspective Files and directories internals the operating

More information

Chapter 12 File Management

Chapter 12 File Management Operating Systems: Internals and Design Principles, 6/E William Stallings Chapter 12 File Management Dave Bremer Otago Polytechnic, N.Z. 2008, Prentice Hall Roadmap Overview File organisation and Access

More information

Chapter 12 File Management. Roadmap

Chapter 12 File Management. Roadmap Operating Systems: Internals and Design Principles, 6/E William Stallings Chapter 12 File Management Dave Bremer Otago Polytechnic, N.Z. 2008, Prentice Hall Overview Roadmap File organisation and Access

More information

Operating Systems CSE 410, Spring 2004. File Management. Stephen Wagner Michigan State University

Operating Systems CSE 410, Spring 2004. File Management. Stephen Wagner Michigan State University Operating Systems CSE 410, Spring 2004 File Management Stephen Wagner Michigan State University File Management File management system has traditionally been considered part of the operating system. Applications

More information

Fundamentals of UNIX Lab 16.2.6 Networking Commands (Estimated time: 45 min.)

Fundamentals of UNIX Lab 16.2.6 Networking Commands (Estimated time: 45 min.) Fundamentals of UNIX Lab 16.2.6 Networking Commands (Estimated time: 45 min.) Objectives: Develop an understanding of UNIX and TCP/IP networking commands Ping another TCP/IP host Use traceroute to check

More information

Some basic features of UNIX

Some basic features of UNIX 4 Case Study: UNIX 2009 Springer-Verlag Berlin Heidelberg / 2010 Joachim Biskup TU Dortmund Security in Computing Systems: Case Study: UNIX - 04. 02. 2010 115 Some basic features of UNIX UNIX supports

More information

Outline. Definition. Name spaces Name resolution Example: The Domain Name System Example: X.500, LDAP. Names, Identifiers and Addresses

Outline. Definition. Name spaces Name resolution Example: The Domain Name System Example: X.500, LDAP. Names, Identifiers and Addresses Outline Definition Names, Identifiers and Addresses Name spaces Name resolution Example: The Domain Name System Example: X.500, LDAP CS550: Advanced Operating Systems 2 A name in a distributed system is

More information

Prof. Dr. Ing. Axel Hunger Dipl.-Ing. Bogdan Marin. Operation Systems and Computer Networks Betriebssysteme und Computer Netzwerke

Prof. Dr. Ing. Axel Hunger Dipl.-Ing. Bogdan Marin. Operation Systems and Computer Networks Betriebssysteme und Computer Netzwerke Ex 2 File Systems A file is a logical collection of information and a file system is a collection of files, where the latter may also include a variety of other objects that share many of the properties

More information

COSC 6374 Parallel Computation. Parallel I/O (I) I/O basics. Concept of a clusters

COSC 6374 Parallel Computation. Parallel I/O (I) I/O basics. Concept of a clusters COSC 6374 Parallel Computation Parallel I/O (I) I/O basics Spring 2008 Concept of a clusters Processor 1 local disks Compute node message passing network administrative network Memory Processor 2 Network

More information

Filing Systems. Filing Systems

Filing Systems. Filing Systems Filing Systems At the outset we identified long-term storage as desirable characteristic of an OS. EG: On-line storage for an MIS. Convenience of not having to re-write programs. Sharing of data in an

More information

Advanced Event Viewer Manual

Advanced Event Viewer Manual Advanced Event Viewer Manual Document version: 2.2944.01 Download Advanced Event Viewer at: http://www.advancedeventviewer.com Page 1 Introduction Advanced Event Viewer is an award winning application

More information

FINAL DoIT 04.01.2013- v.8 APPLICATION SECURITY PROCEDURE

FINAL DoIT 04.01.2013- v.8 APPLICATION SECURITY PROCEDURE Purpose: This procedure identifies what is required to ensure the development of a secure application. Procedure: The five basic areas covered by this document include: Standards for Privacy and Security

More information

Using Network Attached Storage with Linux. by Andy Pepperdine

Using Network Attached Storage with Linux. by Andy Pepperdine Using Network Attached Storage with Linux by Andy Pepperdine I acquired a WD My Cloud device to act as a demonstration, and decide whether to use it myself later. This paper is my experience of how to

More information

USING USER ACCESS CONTROL LISTS (ACLS) TO MANAGE FILE PERMISSIONS WITH A LENOVO NETWORK STORAGE DEVICE

USING USER ACCESS CONTROL LISTS (ACLS) TO MANAGE FILE PERMISSIONS WITH A LENOVO NETWORK STORAGE DEVICE White Paper USING USER ACCESS CONTROL LISTS (ACLS) TO MANAGE FILE PERMISSIONS WITH A LENOVO NETWORK STORAGE DEVICE CONTENTS Executive Summary 1 Introduction 1 Audience 2 Terminology 2 Windows Concepts

More information

Using SSH Secure Shell Client for FTP

Using SSH Secure Shell Client for FTP Using SSH Secure Shell Client for FTP The SSH Secure Shell for Workstations Windows client application features this secure file transfer protocol that s easy to use. Access the SSH Secure FTP by double-clicking

More information

Operating Systems. 07.02 File system mounting, sharing, and protection. File System Mounting

Operating Systems. 07.02 File system mounting, sharing, and protection. File System Mounting 07.02 File system mounting, sharing, and protection emanuele lattanzi isti information science and technology institute 1/15 File System Mounting A file system must be mounted before it can be accessed

More information

Rsync-enabled NAS Hardware Compatibility List

Rsync-enabled NAS Hardware Compatibility List WHITEPAPER BackupAssist Version 5.1 www.backupassist.com Cortex I.T. Labs 2001-2008 2 Contents Introduction... 3 Hardware Setup Instructions... 3 QNAP TS-409... 3 Netgear ReadyNas NV+... 5 Drobo rev1...

More information

Getting Started Guide for FTP

Getting Started Guide for FTP Edition 1.0 Getting Started Guide for FTP What is FTP? FTP (File Transfer Protocol) is a standard procedure for moving files between two computers over the internet. FTP is commonly used to upload/download

More information

CIS 551 / TCOM 401 Computer and Network Security. Spring 2005 Lecture 4

CIS 551 / TCOM 401 Computer and Network Security. Spring 2005 Lecture 4 CIS 551 / TCOM 401 Computer and Network Security Spring 2005 Lecture 4 Access Control: The Big Picture Objects - resources being protected E.g. files, devices, etc. Subjects - active entities E.g. processes,

More information

1 File Management. 1.1 Naming. COMP 242 Class Notes Section 6: File Management

1 File Management. 1.1 Naming. COMP 242 Class Notes Section 6: File Management COMP 242 Class Notes Section 6: File Management 1 File Management We shall now examine how an operating system provides file management. We shall define a file to be a collection of permanent data with

More information

TOSHIBA GA-1310. Printing from Windows

TOSHIBA GA-1310. Printing from Windows TOSHIBA GA-1310 Printing from Windows 2009 Electronics for Imaging, Inc. The information in this publication is covered under Legal Notices for this product. 45081979 04 February 2009 CONTENTS 3 CONTENTS

More information

TEL2821/IS2150: INTRODUCTION TO SECURITY Lab: Operating Systems and Access Control

TEL2821/IS2150: INTRODUCTION TO SECURITY Lab: Operating Systems and Access Control TEL2821/IS2150: INTRODUCTION TO SECURITY Lab: Operating Systems and Access Control Version 3.4, Last Edited 9/10/2011 Students Name: Date of Experiment: Read the following guidelines before working in

More information

15 AFS File Sharing. Client/Server Computing. Distributed File Systems

15 AFS File Sharing. Client/Server Computing. Distributed File Systems 15 AFS File Sharing Adapted from the Open AFS Guide, http://openafs.org/doc/ AFS makes it easy for people to work together on the same files, no matter where the files are located. AFS users do not have

More information

Desktop : Ubuntu 10.04 Desktop, Ubuntu 12.04 Desktop Server : RedHat EL 5, RedHat EL 6, Ubuntu 10.04 Server, Ubuntu 12.04 Server, CentOS 5, CentOS 6

Desktop : Ubuntu 10.04 Desktop, Ubuntu 12.04 Desktop Server : RedHat EL 5, RedHat EL 6, Ubuntu 10.04 Server, Ubuntu 12.04 Server, CentOS 5, CentOS 6 201 Datavoice House, PO Box 267, Stellenbosch, 7599 16 Elektron Avenue, Technopark, Tel: +27 218886500 Stellenbosch, 7600 Fax: +27 218886502 Adept Internet (Pty) Ltd. Reg. no: 1984/01310/07 VAT No: 4620143786

More information

IDENTITIES, ACCESS TOKENS, AND THE ISILON ONEFS USER MAPPING SERVICE

IDENTITIES, ACCESS TOKENS, AND THE ISILON ONEFS USER MAPPING SERVICE White Paper IDENTITIES, ACCESS TOKENS, AND THE ISILON ONEFS USER MAPPING SERVICE Abstract The OneFS user mapping service combines a user s identities from different directory services into a single access

More information

National Fire Incident Reporting System (NFIRS 5.0) Configuration Tool User's Guide

National Fire Incident Reporting System (NFIRS 5.0) Configuration Tool User's Guide National Fire Incident Reporting System (NFIRS 5.0) Configuration Tool User's Guide NFIRS 5.0 Software Version 5.6 1/7/2009 Department of Homeland Security Federal Emergency Management Agency United States

More information

TELE 301 Lecture 7: Linux/Unix file

TELE 301 Lecture 7: Linux/Unix file Overview Last Lecture Scripting This Lecture Linux/Unix file system Next Lecture System installation Sources Installation and Getting Started Guide Linux System Administrators Guide Chapter 6 in Principles

More information

Design. Syntactic Issues

Design. Syntactic Issues Design A single unified logging process is an essential component of computer security mechanisms. The design of the logging subsystem is an integral part of the overall system design. The auditing mechanism,

More information

CEN 559 Selected Topics in Computer Engineering. Dr. Mostafa H. Dahshan KSU CCIS mdahshan@ccis.ksu.edu.sa

CEN 559 Selected Topics in Computer Engineering. Dr. Mostafa H. Dahshan KSU CCIS mdahshan@ccis.ksu.edu.sa CEN 559 Selected Topics in Computer Engineering Dr. Mostafa H. Dahshan KSU CCIS mdahshan@ccis.ksu.edu.sa Access Control Access Control Which principals have access to which resources files they can read

More information

Clustered Data ONTAP 8.3

Clustered Data ONTAP 8.3 Clustered Data ONTAP 8.3 File Access Management Guide for NFS NetApp, Inc. 495 East Java Drive Sunnyvale, CA 94089 U.S. Telephone: +1 (408) 822-6000 Fax: +1 (408) 822-4501 Support telephone: +1 (888) 463-8277

More information

File Management. Chapter 12

File Management. Chapter 12 Chapter 12 File Management File is the basic element of most of the applications, since the input to an application, as well as its output, is usually a file. They also typically outlive the execution

More information

Two Parts. Filesystem Interface. Filesystem design. Interface the user sees. Implementing the interface

Two Parts. Filesystem Interface. Filesystem design. Interface the user sees. Implementing the interface File Management Two Parts Filesystem Interface Interface the user sees Organization of the files as seen by the user Operations defined on files Properties that can be read/modified Filesystem design Implementing

More information

Managing Celerra for the Windows Environment

Managing Celerra for the Windows Environment Managing Celerra for the Windows Environment P/N 300-002-679 Rev A01 March 2006 Contents Introduction..................................................3 Windows and multiprotocol documentation....................3

More information

Case Studies. Joint software development Mail 1 / 38. Case Studies Joint Software Development. Mailers

Case Studies. Joint software development Mail 1 / 38. Case Studies Joint Software Development. Mailers Joint software development Mail 1 / 38 Situations Roles Permissions Why Enforce Access Controls? Unix Setup Windows ACL Setup Reviewer/Tester Access Medium-Size Group Basic Structure Version Control Systems

More information

File-System Implementation

File-System Implementation File-System Implementation 11 CHAPTER In this chapter we discuss various methods for storing information on secondary storage. The basic issues are device directory, free space management, and space allocation

More information

Server Account Management

Server Account Management Server Account Management Setup Guide Contents: About Server Account Management Setting Up and Running a Server Access Scan Addressing Server Access Findings View Server Access Scan Findings Act on Server

More information

RFG Secure FTP. Web Interface

RFG Secure FTP. Web Interface RFG Secure FTP Web Interface Step 1: Getting to the Secure FTP Web Interface: Open your preferred web browser and type the following address: http://ftp.raddon.com After you hit enter, you will be taken

More information

Network Attached Storage. Jinfeng Yang Oct/19/2015

Network Attached Storage. Jinfeng Yang Oct/19/2015 Network Attached Storage Jinfeng Yang Oct/19/2015 Outline Part A 1. What is the Network Attached Storage (NAS)? 2. What are the applications of NAS? 3. The benefits of NAS. 4. NAS s performance (Reliability

More information

Configuration Worksheets for Oracle WebCenter Ensemble 10.3

Configuration Worksheets for Oracle WebCenter Ensemble 10.3 Configuration Worksheets for Oracle WebCenter Ensemble 10.3 This document contains worksheets for installing and configuring Oracle WebCenter Ensemble 10.3. Print this document and use it to gather the

More information

Outline. File Management Tanenbaum, Chapter 4. Files. File Management. Objectives for a File Management System

Outline. File Management Tanenbaum, Chapter 4. Files. File Management. Objectives for a File Management System Outline File Management Tanenbaum, Chapter 4 Files and directories from the programmer (and user) perspective Files and directory internals the operating system perspective COMP3231 Operating Systems 1

More information

Introduction to Linux (Authentication Systems, User Accounts, LDAP and NIS) Süha TUNA Res. Assist.

Introduction to Linux (Authentication Systems, User Accounts, LDAP and NIS) Süha TUNA Res. Assist. Introduction to Linux (Authentication Systems, User Accounts, LDAP and NIS) Süha TUNA Res. Assist. Outline 1. What is authentication? a. General Informations 2. Authentication Systems in Linux a. Local

More information

Understanding and Using NetInfo. Includes information on setting up Mac OS X Server and NetInfo to increase the power of your Mac OS X network

Understanding and Using NetInfo. Includes information on setting up Mac OS X Server and NetInfo to increase the power of your Mac OS X network Understanding and Using NetInfo Includes information on setting up Mac OS X Server and NetInfo to increase the power of your Mac OS X network K Apple Computer, Inc. 2001 Apple Computer, Inc. All rights

More information

Database security issues PETRA BILIĆ ALEXANDER SPARBER

Database security issues PETRA BILIĆ ALEXANDER SPARBER Database security issues PETRA BILIĆ ALEXANDER SPARBER Introduction Database security is one aspect of computer security It uses different information security controls to protect databases Information

More information

Backing up AIR to Microsoft Windows

Backing up AIR to Microsoft Windows Backing up AIR to Microsoft Windows Dear Valued Customer, Avaya realizes the importance of your data and the significance of a backup and restore strategy for this data. To assist you in performing a backup

More information

The Mac OS X Server Essentials v10.5 Exam Skills Assessment Guide

The Mac OS X Server Essentials v10.5 Exam Skills Assessment Guide The Mac OS X Server Essentials v10.5 Exam Skills Assessment Guide To Register This exam is offered at Apple Authorized Training Centers and Prometric Testing Centers worldwide. For information on exam

More information

Network File System (NFS)

Network File System (NFS) Network File System (NFS) Brad Karp UCL Computer Science CS GZ03 / M030 10 th October 2011 NFS Is Relevant Original paper from 1985 Very successful, still widely used today Early result; much subsequent

More information

Distributed File Systems. Chapter 10

Distributed File Systems. Chapter 10 Distributed File Systems Chapter 10 Distributed File System a) A distributed file system is a file system that resides on different machines, but offers an integrated view of data stored on remote disks.

More information

Chapter 9: File-System Interface. Operating System Concepts essentials 8 th Edition

Chapter 9: File-System Interface. Operating System Concepts essentials 8 th Edition Chapter 9: File-System Interface Operating System Concepts essentials 8 th Edition Silberschatz, Galvin and Gagne 2011 Chapter 9: File-System Interface File Concept Access Methods Disk and Directory Structure

More information

ADSelfService Plus Client Software Installation Guide

ADSelfService Plus Client Software Installation Guide ADSelfService Plus Client Software Installation Guide ( I n s t a l l a t io n t h r o u g h A DS e l f S e r v ic e P l u s w e b p o r t a l a n d M a n u a l I n s t a l l a t io n ) 1 Table of Contents

More information

Instructions for Adding a MacOS 10.4.x Server to ASURITE for File Sharing. Installation Section

Instructions for Adding a MacOS 10.4.x Server to ASURITE for File Sharing. Installation Section Instructions for Adding a MacOS 10.4.x Server to ASURITE for File Sharing Installation Section Purpose: We are setting up a server in ASU s specific environment. Power on the Server Insert the CD Hold

More information

THE FIJI GOVERNMENT INFORMATION TECHNOLOGY DATABASE CREDENTIALS POLICY. Version 1.00.00

THE FIJI GOVERNMENT INFORMATION TECHNOLOGY DATABASE CREDENTIALS POLICY. Version 1.00.00 THE FIJI GOVERNMENT INFORMATION TECHNOLOGY DATABASE CREDENTIALS POLICY Version 1.00.00 DOCUMENT APPROVAL This document has been reviewed and authorized by the following personnel. Writer Reviewer Position:

More information

Adam Retter. Security. in exist-db. Security in exist-db http://www.adamretter.org.uk adam.retter@googlemail.com

Adam Retter. Security. in exist-db. Security in exist-db http://www.adamretter.org.uk adam.retter@googlemail.com Adam Retter Security in exist-db Flickr: CC-BY: security by protohiro In the Past exist-db 1.4 and before Unix like Security Model (attempted) root user => admin user wheel group => DBA group Used rwu

More information

Administrasi dan Manajemen Jaringan 2. File Transfer Protocol (FTP)

Administrasi dan Manajemen Jaringan 2. File Transfer Protocol (FTP) Administrasi dan Manajemen Jaringan 2. File Transfer Protocol (FTP) M. Udin Harun Al Rasyid, Ph.D http://lecturer.eepis-its.edu/~udinharun udinharun@eepis-its.edu Lab Jaringan Komputer (C-307) Table of

More information

µtasker Document FTP Client

µtasker Document FTP Client Embedding it better... µtasker Document FTP Client utaskerftp_client.doc/1.01 Copyright 2012 M.J.Butcher Consulting Table of Contents 1. Introduction...3 2. FTP Log-In...4 3. FTP Operation Modes...4 4.

More information

Access Control Lists in Linux & Windows

Access Control Lists in Linux & Windows Access Control Lists in Linux & Windows Vasudevan Nagendra & Yaohui Chen Categorization: Access Control Mechanisms Discretionary Access Control (DAC): Owner of object specifies who can access object (files/directories)

More information

Simple Solution for a Location Service. Naming vs. Locating Entities. Forwarding Pointers (2) Forwarding Pointers (1)

Simple Solution for a Location Service. Naming vs. Locating Entities. Forwarding Pointers (2) Forwarding Pointers (1) Naming vs. Locating Entities Till now: resources with fixed locations (hierarchical, caching,...) Problem: some entity may change its location frequently Simple solution: record aliases for the new address

More information

Manual POLICY PATROL SECURE FILE TRANSFER

Manual POLICY PATROL SECURE FILE TRANSFER Manual POLICY PATROL SECURE FILE TRANSFER MANUAL Policy Patrol Secure File Transfer This manual, and the software described in this manual, are copyrighted. No part of this manual or the described software

More information

SANS Institute First Five Quick Wins

SANS Institute First Five Quick Wins #1 QUICK WIN- APPLICATION WHITELISTING SANS Critical Controls: #2: Inventory of Authorized and Unauthorized Software 1) Deploy application whitelisting technology that allows systems to run software only

More information

Exploiting the Web with Tivoli Storage Manager

Exploiting the Web with Tivoli Storage Manager Exploiting the Web with Tivoli Storage Manager Oxford University ADSM Symposium 29th Sept. - 1st Oct. 1999 Roland Leins, IBM ITSO Center - San Jose leins@us.ibm.com Agenda The Web Client Concept Tivoli

More information

File Systems Management and Examples

File Systems Management and Examples File Systems Management and Examples Today! Efficiency, performance, recovery! Examples Next! Distributed systems Disk space management! Once decided to store a file as sequence of blocks What s the size

More information

Web Application Report

Web Application Report Web Application Report This report includes important security information about your Web Application. Security Report This report was created by IBM Rational AppScan 8.5.0.1 11/14/2012 8:52:13 AM 11/14/2012

More information

Setting Up Scan to SMB on TaskALFA series MFP s.

Setting Up Scan to SMB on TaskALFA series MFP s. Setting Up Scan to SMB on TaskALFA series MFP s. There are three steps necessary to set up a new Scan to SMB function button on the TaskALFA series color MFP. 1. A folder must be created on the PC and

More information

POLICY PATROL MFT. Manual

POLICY PATROL MFT. Manual POLICY PATROL MFT Manual MANUAL Policy Patrol MFT This manual, and the software described in this manual, are copyrighted. No part of this manual or the described software may be copied, reproduced, translated

More information

MCTS Guide to Microsoft Windows Server 2008 Applications Infrastructure Configuration (Exam # 70-643)

MCTS Guide to Microsoft Windows Server 2008 Applications Infrastructure Configuration (Exam # 70-643) MCTS Guide to Microsoft Windows Server 2008 Applications Infrastructure Configuration (Exam # 70-643) Chapter Six Configuring Windows Server 2008 Web Services, Part 1 Objectives Create and configure Web

More information

ONEFS MULTIPROTOCOL SECURITY UNTANGLED

ONEFS MULTIPROTOCOL SECURITY UNTANGLED White Paper ONEFS MULTIPROTOCOL SECURITY UNTANGLED Abstract This paper describes the role that identity management, authentication, and access control play in the security system of the EMC Isilon OneFS

More information

A Unix Network Protocol Security Study: Network Information Service

A Unix Network Protocol Security Study: Network Information Service A Unix Network Protocol Security Study: Network Information Service Introduction David K. Hess, David R. Safford and Udo W. Pooch Texas A&M University dhess@cs.tamu.edu This note is a study of the security

More information

NetInfo Editions 4.x User Manual

NetInfo Editions 4.x User Manual NetInfo Editions 4.x User Manual Xedoc Software Development Pty. Ltd. May 1997 NetInfo Editions 4.x User Manual Xedoc Software Development Pty Ltd. PO Box 3038 Burnley North VIC 3121 Australia Telephone

More information

Hooks could have been left around for the imposter to regain control. A.Arpaci-Dusseau. Remove all files from disk and reinstall all software

Hooks could have been left around for the imposter to regain control. A.Arpaci-Dusseau. Remove all files from disk and reinstall all software UNIVERSITY of WISCONSIN-MADISON Computer Sciences Department CS 537 A. Arpaci-Dusseau Intro to Operating Systems Spring 2000 Security Solutions and Encryption Questions answered in these notes: How does

More information

Case Study: Access control 1 / 39

Case Study: Access control 1 / 39 Case Study: Access control 1 / 39 Joint software development Mail 2 / 39 Situations Roles Permissions Why Enforce Access Controls? Classic Unix Setup ACL Setup Reviewer/Tester Access Medium-Size Group

More information

4.1 NAMING ENTITIES 184 NAMING CHAP. 4. 4.1.1 Names, Identifiers, and Addresses

4.1 NAMING ENTITIES 184 NAMING CHAP. 4. 4.1.1 Names, Identifiers, and Addresses 184 NAMING CHAP. 4 4.1 NAMING ENTITIES In this section, we first concentrate on different kinds of names, and how names are organized into name spaces. We then continue with a discussion of the important

More information

SSH Secure Client (Telnet & SFTP) Installing & Using SSH Secure Shell for Windows Operation Systems

SSH Secure Client (Telnet & SFTP) Installing & Using SSH Secure Shell for Windows Operation Systems SSH Secure Client (Telnet & SFTP) Installing & Using SSH Secure Shell for Windows Operation Systems What is SSH?: SSH is an application that protects the TCP/IP connections between two computers. The software

More information

Configuring the WT-4 for ftp (Ad-hoc Mode)

Configuring the WT-4 for ftp (Ad-hoc Mode) En Configuring the WT-4 for ftp (Ad-hoc Mode) Mac OS X Introduction This document provides basic instructions on configuring the WT-4 wireless transmitter and a Mac OS X (10.5.2) ftp server for transmission

More information

ichip FTP Client Theory of Operation Version 1.32

ichip FTP Client Theory of Operation Version 1.32 ichip FTP Client Theory of Operation Version 1.32 November 2003 Introduction The FTP protocol is described in RFC 959. General FTP (File Transfer Protocol) is defined as a protocol for file transfer between

More information

CS 392/CS 681 - Computer Security. Module 17 Auditing

CS 392/CS 681 - Computer Security. Module 17 Auditing CS 392/CS 681 - Computer Security Module 17 Auditing Auditing Audit Independent review and examination of records and activities to assess the adequacy of system controls, to ensure compliance with established

More information

SFTP Server User Login Instructions. Open Internet explorer and enter the following url: https://sftp.sae.org

SFTP Server User Login Instructions. Open Internet explorer and enter the following url: https://sftp.sae.org SFTP Server User Login Instructions Open Internet explorer and enter the following url: https://sftp.sae.org You will be prompted for a user id and password as such. Please enter your account id and password.

More information

Local Caching Servers (LCS): User Manual

Local Caching Servers (LCS): User Manual Local Caching Servers (LCS): User Manual Table of Contents Local Caching Servers... 1 Supported Browsers... 1 Getting Help... 1 System Requirements... 2 Macintosh... 2 Windows... 2 Linux... 2 Downloading

More information

Clustered Data ONTAP 8.2

Clustered Data ONTAP 8.2 Updated for 8.2.1 Clustered Data ONTAP 8.2 File Access Management Guide for NFS NetApp, Inc. 495 East Java Drive Sunnyvale, CA 94089 U.S. Telephone: +1 (408) 822-6000 Fax: +1 (408) 822-4501 Support telephone:

More information

Overview of Network Security The need for network security Desirable security properties Common vulnerabilities Security policy designs

Overview of Network Security The need for network security Desirable security properties Common vulnerabilities Security policy designs Overview of Network Security The need for network security Desirable security properties Common vulnerabilities Security policy designs Why Network Security? Keep the bad guys out. (1) Closed networks

More information

Module 2: File Systems and Management

Module 2: File Systems and Management Module 2: File Systems and Management In the previous module, we emphasized that a computer system processes and stores information. Usually, during processing computers need to frequently access primary

More information

SSSD. Client side identity management. LinuxAlt 2012 Jakub Hrozek 3. listopadu 2012

SSSD. Client side identity management. LinuxAlt 2012 Jakub Hrozek 3. listopadu 2012 Client side identity management LinuxAlt 2012 Jakub Hrozek 3. listopadu 2012 Section 1 Centralized user databases Centralized user databases User accounts in a large environment it is not practical to

More information

Project: Simulated Encrypted File System (SEFS)

Project: Simulated Encrypted File System (SEFS) Project: Simulated Encrypted File System (SEFS) Omar Chowdhury Fall 2015 CS526: Information Security 1 Motivation Traditionally files are stored in the disk in plaintext. If the disk gets stolen by a perpetrator,

More information

21 Things You Didn t Used to Know About RACF

21 Things You Didn t Used to Know About RACF 21 Things You Didn t Used to Know About RACF (A Technical Update for IT Auditors) Stuart Henderson The Henderson Group (301) 229-7187 1 Here Are 21 Things Auditors Should Know About RACF One Person s Opinion,

More information