Using Transparent Compression to Improve SSD-Based I/O Caches
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HTTP-FUSE Xenoppix
HTTP-FUSE Xenoppix Kuniyasu Suzaki† Toshiki Yagi† Kengo Iijima† Kenji Kitagawa†† Shuichi Tashiro††† National Institute of Advanced Industrial Science and Technology† Alpha Systems Inc.†† Information-Technology Promotion Agency, Japan††† {k.suzaki,yagi-toshiki,k-iijima}@aist.go.jp [email protected], [email protected] Abstract a CD-ROM. Furthermore it requires remaking the entire CD-ROM when a bit of data is up- dated. The other solution is a Virtual Machine We developed “HTTP-FUSE Xenoppix” which which enables us to install many OSes and ap- boots Linux, Plan9, and NetBSD on Virtual plications easily. However, that requires in- Machine Monitor “Xen” with a small bootable stalling virtual machine software. (6.5MB) CD-ROM. The bootable CD-ROM in- cludes boot loader, kernel, and miniroot only We have developed “Xenoppix” [1], which and most part of files are obtained via Internet is a combination of CD/DVD bootable Linux with network loopback device HTTP-FUSE “KNOPPIX” [2] and Virtual Machine Monitor CLOOP. It is made from cloop (Compressed “Xen” [3, 4]. Xenoppix boots Linux (KNOP- Loopback block device) and FUSE (Filesys- PIX) as Host OS and NetBSD or Plan9 as Guest tem USErspace). HTTP-FUSE CLOOP can re- OS with a bootable DVD only. KNOPPIX construct a block device from many small block is advanced in automatic device detection and files of HTTP servers. In this paper we describe driver integration. It prepares the Xen environ- the detail of the implementation and its perfor- ment and Guest OSes don’t need to worry about mance. lack of device drivers. -
How to Create a Custom Live CD for Secure Remote Incident Handling in the Enterprise
How to Create a Custom Live CD for Secure Remote Incident Handling in the Enterprise Abstract This paper will document a process to create a custom Live CD for secure remote incident handling on Windows and Linux systems. The process will include how to configure SSH for remote access to the Live CD even when running behind a NAT device. The combination of customization and secure remote access will make this process valuable to incident handlers working in enterprise environments with limited remote IT support. Bert Hayes, [email protected] How to Create a Custom Live CD for Remote Incident Handling 2 Table of Contents Abstract ...........................................................................................................................................1 1. Introduction ............................................................................................................................5 2. Making Your Own Customized Debian GNU/Linux Based System........................................7 2.1. The Development Environment ......................................................................................7 2.2. Making Your Dream Incident Handling System...............................................................9 2.3. Hardening the Base Install.............................................................................................11 2.3.1. Managing Root Access with Sudo..........................................................................11 2.4. Randomizing the Handler Password at Boot Time ........................................................12 -
Open Source Licensing Information for Cisco IP Phone 8800 Series
Open Source Used In Cisco IP Phone 8800 Series 12.1(1) Cisco Systems, Inc. www.cisco.com Cisco has more than 200 offices worldwide. Addresses, phone numbers, and fax numbers are listed on the Cisco website at www.cisco.com/go/offices. Text Part Number: 78EE117C99-163803748 Open Source Used In Cisco IP Phone 8800 Series 12.1(1) 1 This document contains licenses and notices for open source software used in this product. With respect to the free/open source software listed in this document, if you have any questions or wish to receive a copy of any source code to which you may be entitled under the applicable free/open source license(s) (such as the GNU Lesser/General Public License), please contact us at [email protected]. In your requests please include the following reference number 78EE117C99-163803748 Contents 1.1 bluez 4.101 :MxC-1.1C R4.0 1.1.1 Available under license 1.2 BOOST C++ Library 1.63.0 1.2.1 Available under license 1.3 busybox 1.21.0 1.3.1 Available under license 1.4 Busybox 1.23.1 1.4.1 Available under license 1.5 cjose 0.4.1 1.5.1 Available under license 1.6 cppformat 2.0.0 1.6.1 Available under license 1.7 curl 7.26.0 1.7.1 Available under license 1.8 dbus 1.4.1 :MxC-1.1C R4.0 1.8.1 Available under license 1.9 DirectFB library and utilities 1.4.5 1.9.1 Available under license 1.10 dnsmasq 2.46 1.10.1 Available under license 1.11 flite 2.0.0 1.11.1 Available under license 1.12 glibc 2.13 1.12.1 Available under license 1.13 hostapd 2.0 :MxC-1.1C R4.0 1.13.1 Available under license Open Source Used -
De-Anonymizing Live Cds Through Physical Memory Analysis
De-Anonymizing Live CDs through Physical Memory Analysis Andrew Case [email protected] Digital Forensics Solutions Abstract Traditional digital forensics encompasses the examination of data from an offline or “dead” source such as a disk image. Since the filesystem is intact on these images, a number of forensics techniques are available for analysis such as file and metadata examination, timelining, deleted file recovery, indexing, and searching. Live CDs present a serious problem for this investigative model, however, since the OS and applications execute in a RAM-only environment and do not save data on non-volatile storage devices such as the local disk. In order to solve this problem, we present a number of techniques that support complete recovery of a live CD’s in-memory filesystem and partial recovery of its deleted contents. We also present memory analysis of the popular Tor application, since it is used by a number of live CDs in an attempt to keep network communications encrypted and anonymous. 1 Introduction Traditional digital forensics encompasses the examination of data from an offline or “dead” source such as a disk image. Under normal circumstances, evidence is obtained by first creating an exact, bit-for-bit copy of the target disk, followed by hashing of both the target disk and the new copy. If these hashes match then it is known that an exact copy has been made, and the hash is recorded to later prove that evidence was not modified during the investigation. Besides satisfying legal requirements, obtaining a bit-for-bit copy of data provides investigators with a wealth of information to examine and makes available a number of forensics techniques. -
Hardware-Driven Evolution in Storage Software by Zev Weiss A
Hardware-Driven Evolution in Storage Software by Zev Weiss A dissertation submitted in partial fulfillment of the requirements for the degree of Doctor of Philosophy (Computer Sciences) at the UNIVERSITY OF WISCONSIN–MADISON 2018 Date of final oral examination: June 8, 2018 ii The dissertation is approved by the following members of the Final Oral Committee: Andrea C. Arpaci-Dusseau, Professor, Computer Sciences Remzi H. Arpaci-Dusseau, Professor, Computer Sciences Michael M. Swift, Professor, Computer Sciences Karthikeyan Sankaralingam, Professor, Computer Sciences Johannes Wallmann, Associate Professor, Mead Witter School of Music i © Copyright by Zev Weiss 2018 All Rights Reserved ii To my parents, for their endless support, and my cousin Charlie, one of the kindest people I’ve ever known. iii Acknowledgments I have taken what might be politely called a “scenic route” of sorts through grad school. While Ph.D. students more focused on a rapid graduation turnaround time might find this regrettable, I am glad to have done so, in part because it has afforded me the opportunities to meet and work with so many excellent people along the way. I owe debts of gratitude to a large cast of characters: To my advisors, Andrea and Remzi Arpaci-Dusseau. It is one of the most common pieces of wisdom imparted on incoming grad students that one’s relationship with one’s advisor (or advisors) is perhaps the single most important factor in whether these years of your life will be pleasant or unpleasant, and I feel exceptionally fortunate to have ended up iv with the advisors that I’ve had. -
Deep Compression
COVER STORY Cloop DEEPBlock device compression COMPRESSION with the cloop module KYRO, photocase.com KYRO, The cloop module lets you manage compression at the block device 512 bytes), and they are usually used for random access storage like ramdisks, level. Read on to learn how Knoppix and other Live CDs fit all that CD-ROMs, floppy disks, hard disks, and hard disk partitions. software on a single disc. BY KLAUS KNOPPER Filesystems are a logical representa- tion of ordered data that is often present loop is a kernel block device block-based devices. If you look into the on a block device. A filesystem turns raw module used in Live CDs such output of ls -l /dev, you will easily recog- data into the familiar directory/file view. Cas Knoppix. The cloop module nize these devices by the prefix – c for The mount command is the bridge be- allows the system to read compressed character-based and b for block-based tween a block device partition and its data, usually from a file, thus creating devices – at the beginning of the output projection into a mount point directory. compressed virtual disks. Using cloop, line (see Listing 1). a Linux installation of about 2GB fits on Character-based devices, such as tape Cloop: A Compressed a single 700MB CD-R disc. In this article, drives, mice, and gamepads, provide se- Loopback Block Device I look at how cloop works and provide quential, character-by-character access One block device included in any Linux some insight into general kernel struc- to data. -
Elinos Product Overview
SYSGO Product Overview ELinOS 7 Industrial Grade Linux ELinOS is a SYSGO Linux distribution to help developers save time and effort by focusing on their application. Our Industrial Grade Linux with user-friendly IDE goes along with the best selection of software packages to meet our cog linux Qt LOCK customers needs, and with the comfort of world-class technical support. ELinOS now includes Docker support Feature LTS Qt Open SSH Configurator Kernel embedded Open VPN in order to isolate applications running on the same system. laptop Q Bug Shield-Virus Docker Eclipse-based QEMU-based Application Integrated Docker IDE HW Emulators Debugging Firewall Support ELINOS FEATURES MANAGING EMBEDDED LINUX VERSATILITY • Industrial Grade Creating an Embedded Linux based system is like solving a puzzle and putting • Eclipse-based IDE for embedded the right pieces together. This requires a deep knowledge of Linux’s versatility Systems (CODEO) and takes time for the selection of components, development of Board Support • Multiple Linux kernel versions Packages and drivers, and testing of the whole system – not only for newcomers. incl. Kernel 4.19 LTS with real-time enhancements With ELinOS, SYSGO offers an ‘out-of-the-box’ experience which allows to focus • Quick and easy target on the development of competitive applications itself. ELinOS incorporates the system configuration appropriate tools, such as a feature configurator to help you build the system and • Hardware Emulation (QEMU) boost your project success, including a graphical configuration front-end with a • Extensive file system support built-in integrity validation. • Application debugging • Target analysis APPLICATION & CONFIGURATION ENVIRONMENT • Runs out-of-the-box on PikeOS • Validated and tested for In addition to standard tools, remote debugging, target system monitoring and PowerPC, x86, ARM timing behaviour analyses are essential for application development. -
Unionfs: User- and Community-Oriented Development of a Unification File System
Unionfs: User- and Community-Oriented Development of a Unification File System David Quigley, Josef Sipek, Charles P. Wright, and Erez Zadok Stony Brook University {dquigley,jsipek,cwright,ezk}@cs.sunysb.edu Abstract If a file exists in multiple branches, the user sees only the copy in the higher-priority branch. Unionfs allows some branches to be read-only, Unionfs is a stackable file system that virtually but as long as the highest-priority branch is merges a set of directories (called branches) read-write, Unionfs uses copy-on-write seman- into a single logical view. Each branch is as- tics to provide an illusion that all branches are signed a priority and may be either read-only writable. This feature allows Live-CD develop- or read-write. When the highest priority branch ers to give their users a writable system based is writable, Unionfs provides copy-on-write se- on read-only media. mantics for read-only branches. These copy- on-write semantics have lead to widespread There are many uses for namespace unifica- use of Unionfs by LiveCD projects including tion. The two most common uses are Live- Knoppix and SLAX. In this paper we describe CDs and diskless/NFS-root clients. On Live- our experiences distributing and maintaining CDs, by definition, the data is stored on a read- an out-of-kernel module since November 2004. only medium. However, it is very convenient As of March 2006 Unionfs has been down- for users to be able to modify the data. Uni- loaded by over 6,700 unique users and is used fying the read-only CD with a writable RAM by over two dozen other projects. -
Scibian 9 HPC Installation Guide
Scibian 9 HPC Installation guide CCN-HPC Version 1.9, 2018-08-20 Table of Contents About this document . 1 Purpose . 2 Structure . 3 Typographic conventions . 4 Build dependencies . 5 License . 6 Authors . 7 Reference architecture. 8 1. Hardware architecture . 9 1.1. Networks . 9 1.2. Infrastructure cluster. 10 1.3. User-space cluster . 12 1.4. Storage system . 12 2. External services . 13 2.1. Base services. 13 2.2. Optional services . 14 3. Software architecture . 15 3.1. Overview . 15 3.2. Base Services . 16 3.3. Additional Services. 19 3.4. High-Availability . 20 4. Conventions . 23 5. Advanced Topics . 24 5.1. Boot sequence . 24 5.2. iPXE Bootmenu Generator. 28 5.3. Debian Installer Preseed Generator. 30 5.4. Frontend nodes: SSH load-balancing and high-availability . 31 5.5. Service nodes: DNS load-balancing and high-availability . 34 5.6. Consul and DNS integration. 35 5.7. Scibian diskless initrd . 37 Installation procedure. 39 6. Overview. 40 7. Requirements . 41 8. Temporary installation node . 44 8.1. Base installation . 44 8.2. Administration environment . 44 9. Internal configuration repository . 46 9.1. Base directories . 46 9.2. Organization settings . 46 9.3. Cluster directories . 48 9.4. Puppet configuration . 48 9.5. Cluster definition. 49 9.6. Service role . 55 9.7. Authentication and encryption keys . 56 10. Generic service nodes . 62 10.1. Temporary installation services . 62 10.2. First Run. 62 10.3. Second Run . 64 10.4. Base system installation. 64 10.5. Ceph deployment . 66 10.6. Consul deployment. -
QEMU Version 4.2.0 User Documentation I
QEMU version 4.2.0 User Documentation i Table of Contents 1 Introduction ::::::::::::::::::::::::::::::::::::: 1 1.1 Features :::::::::::::::::::::::::::::::::::::::::::::::::::::::: 1 2 QEMU PC System emulator ::::::::::::::::::: 2 2.1 Introduction :::::::::::::::::::::::::::::::::::::::::::::::::::: 2 2.2 Quick Start::::::::::::::::::::::::::::::::::::::::::::::::::::: 2 2.3 Invocation :::::::::::::::::::::::::::::::::::::::::::::::::::::: 3 2.3.1 Standard options :::::::::::::::::::::::::::::::::::::::::: 3 2.3.2 Block device options :::::::::::::::::::::::::::::::::::::: 12 2.3.3 USB options:::::::::::::::::::::::::::::::::::::::::::::: 23 2.3.4 Display options ::::::::::::::::::::::::::::::::::::::::::: 23 2.3.5 i386 target only::::::::::::::::::::::::::::::::::::::::::: 30 2.3.6 Network options :::::::::::::::::::::::::::::::::::::::::: 31 2.3.7 Character device options:::::::::::::::::::::::::::::::::: 38 2.3.8 Bluetooth(R) options ::::::::::::::::::::::::::::::::::::: 42 2.3.9 TPM device options :::::::::::::::::::::::::::::::::::::: 43 2.3.10 Linux/Multiboot boot specific ::::::::::::::::::::::::::: 44 2.3.11 Debug/Expert options ::::::::::::::::::::::::::::::::::: 45 2.3.12 Generic object creation :::::::::::::::::::::::::::::::::: 54 2.3.13 Device URL Syntax ::::::::::::::::::::::::::::::::::::: 66 2.4 Keys in the graphical frontends :::::::::::::::::::::::::::::::: 69 2.5 Keys in the character backend multiplexer ::::::::::::::::::::: 69 2.6 QEMU Monitor ::::::::::::::::::::::::::::::::::::::::::::::: 70 2.6.1 Commands ::::::::::::::::::::::::::::::::::::::::::::::: -
Smaller Flight Data Recorders{
Available online at http://docs.lib.purdue.edu/jate Journal of Aviation Technology and Engineering 2:2 (2013) 45–55 Smaller Flight Data Recorders{ Yair Wiseman and Alon Barkai Bar-Ilan University Abstract Data captured by flight data recorders are generally stored on the system’s embedded hard disk. A common problem is the lack of storage space on the disk. This lack of space for data storage leads to either a constant effort to reduce the space used by data, or to increased costs due to acquisition of additional space, which is not always possible. File compression can solve the problem, but carries with it the potential drawback of the increased overhead required when writing the data to the disk, putting an excessive load on the system and degrading system performance. The author suggests the use of an efficient compressed file system that both compresses data in real time and ensures that there will be minimal impact on the performance of other tasks. Keywords: flight data recorder, data compression, file system Introduction A flight data recorder is a small line-replaceable computer unit employed in aircraft. Its function is recording pilots’ inputs, electronic inputs, sensor positions and instructions sent to any electronic systems on the aircraft. It is unofficially referred to as a "black box". Flight data recorders are designed to be small and thoroughly fabricated to withstand the influence of high speed impacts and extreme temperatures. A flight data recorder from a commercial aircraft can be seen in Figure 1. State-of-the-art high density flash memory devices have permitted the solid state flight data recorder (SSFDR) to be implemented with much larger memory capacity. -
Key-Based Self-Driven Compression in Columnar Binary JSON
Otto von Guericke University of Magdeburg Department of Computer Science Master's Thesis Key-Based Self-Driven Compression in Columnar Binary JSON Author: Oskar Kirmis November 4, 2019 Advisors: Prof. Dr. rer. nat. habil. Gunter Saake M. Sc. Marcus Pinnecke Institute for Technical and Business Information Systems / Database Research Group Kirmis, Oskar: Key-Based Self-Driven Compression in Columnar Binary JSON Master's Thesis, Otto von Guericke University of Magdeburg, 2019 Abstract A large part of the data that is available today in organizations or publicly is provided in semi-structured form. To perform analytical tasks on these { mostly read-only { semi-structured datasets, Carbon archives were developed as a column-oriented storage format. Its main focus is to allow cache-efficient access to fields across records. As many semi-structured datasets mainly consist of string data and the denormalization introduces redundancy, a lot of storage space is required. However, in Carbon archives { besides a deduplication of strings { there is currently no compression implemented. The goal of this thesis is to discuss, implement and evaluate suitable compression tech- niques to reduce the amount of storage required and to speed up analytical queries on Carbon archives. Therefore, a compressor is implemented that can be configured to apply a combination of up to three different compression algorithms to the string data of Carbon archives. This compressor can be applied with a different configuration per column (per JSON object key). To find suitable combinations of compression algo- rithms for each column, one manual and two self-driven approaches are implemented and evaluated. On a set of ten publicly available semi-structured datasets of different kinds and sizes, the string data can be compressed down to about 53% on average, reducing the whole datasets' size by 20%.