DOCSLIB.ORG

Tuning and Testing the Freebsd 6 TCP Stack

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Tuning and Testing the Freebsd 6 TCP Stack Tuning and Testing the FreeBSD 6 TCP Stack Lawrence Stewart, James Healy Centre for Advanced Internet Architectures, Technical Report 070717B Swinburne University of Technology Melbourne, Australia [email protected], [email protected] Abstract— Tuning an operating system’s network stack II. CONFIGURABLES is crucial in order to achieve optimum performance from network intensive applications. This report discusses some A. The TCP Host Cache of the key factors that affect network performance of FreeBSD 6.x based hosts. It then goes on to explain how The host cache is used to cache connection details to tune the FreeBSD 6.x network stack and how to easily and metrics to improve future performance of connec- test and evaluate the changes made. tions between the same hosts. At the completion of a Index Terms— FreeBSD, TCP, Tuning, Networking, Per- TCP connection, a host will cache information for the formance connection for some defined period of time. If a new connection between the same 2 hosts is initiated before I. INTRODUCTION the cache has expired the entry, the connection will use the cached connection details to “seed” the connection’s The widely used FreeBSD UNIX-like operating sys- internal variables. This allows the connection to reach tem provides a mature, stable and customisable platform, optimal performance significantly faster, as TCP does suitable for many tasks including hosting network inten- not need to go through its usual steps of learning what sive applications and telecommunications research. The the optimal parameters for the connection are. operating system’s network stack plays one of the most The cached details include the Round Trip Time (RTT) important roles in internetworking, as it is the avenue estimate to the remote host, path Maximum Transmission through which all packets enter and exit a device on the Unit (MTU) slow start threshold, congestion window and network. bandwidth-delay product (BDP). The hc metrics struct Current TCP/IP stacks have evolved along with the found in <netinet/tcp hostcache.c> lists the full set of various incremental additional standards documents that connection details stored in the host cache. have appeared over the years, further increasing the com- The FreeBSD sysctl variables that affect the TCP host plexity of an already sophisticated part of the operating cache and their default values are shown in Listing 1. system. Most of the standards have been optional addi- tions to the protocol stack, and have been implemented as such in most operating systems. Listing 1 CAIA’s NewTCP project [1] mandated the use of the net.inet.tcp.hostcache.cachelimit: 15360 FreeBSD [2] operating system as the platform for per- net.inet.tcp.hostcache.hashsize: 512 forming our TCP research. As such, we performed some net.inet.tcp.hostcache.bucketlimit: 30 investigative research into how the FreeBSD TCP/IP net.inet.tcp.hostcache.count: 4 stack operates. This report aims to capture the informa- net.inet.tcp.hostcache.expire: 3600 tion learnt during this process for the benefit of future net.inet.tcp.hostcache.purge: 0 experimental TCP research using FreeBSD. Whilst FreeBSD 6.2-RELEASE was used for the net.inet.tcp.hostcache.cachelimit specifies the FreeBSD TCP/IP stack research we undertook, most of maximum number of cache entries that can be the technical information in this report will be applicable stored in the host cache. It is calculated as the to all FreeBSD 6.x releases, and possibly to earlier (5.x product of the net.inet.tcp.hostcache.hashsize and and 4.x to a lesser extent) or up and coming (7.x and net.inet.tcp.hostcache.bucketlimit variables. If the host beyond) releases. cache ever reaches capacity, it simply begins overwriting CAIA Technical Report 070717B July 2007 page 1 of 6 previous entries, which is not detrimental to the working window for the new connection. However, we discovered of the system at all. this does not occur correctly due to an incorrect assump- net.inet.tcp.hostcache.count lists the number of entries tion in the code, resulting in the congestion window currently in the host cache. always being set to 1 segment. The discussion on the net.inet.tcp.hostcache.expire lists the default time out FreeBSD “net” mailing list regarding this matter is value (in seconds) for cache entries. After initial creation, archived here [3]. The end result of this is that use a cache entry will expire net.inet.tcp.hostcache.expire of the host cache for seeding the initial congestion seconds after creation if a new connection to the same window actually degrades the performance of subsequent host is not made before the expiration. If a new con- connections between hosts, and obscures the intended nection is made, the corresponding cache entry’s expiry behaviour of RFC3390. It is therefore advised that timer is updated as well. changing the value of “TCP HOSTCACHE PRUNE” net.inet.tcp.hostcache.purge will force all current en- and net.inet.tcp.hostcache.expire as previously described tries in the host cache to be removed next time the cache be carried out to mitigate the quirk, in situations where is pruned. After the prune is completed the value will be this may be problematic e.g. experimental research. reset to 0. Note that setting the net.inet.tcp.hostcache.cachelimit In FreeBSD, the host cache is checked for stale tuner variable to 0 does not disable the host cache, and entries every 5 minutes by default. This value can be instead causes the kernel to panic whenever it goes to modified by changing the <netinet/tcp hostcache.c> add a cache entry. source file and recompiling the kernel. The “TCP HOSTCACHE PRUNE” define specifies the B. TCP Extensions period between checks for stale cache entries. A range of additional extensions to TCP have been Under normal circumstances, the default of 5 min- proposed since the initial TCP standard was released. utes is fine. However, when doing experimental re- RFC4614 [4] provides an excellent summary of these search, we ideally limit or remove the affect of vari- various proposals and references to the various Request ables other than the one being studied. Given that For Comment (RFC) documents that propose them. cached connection settings can alter the dynamics of a For the extensions supported by FreeBSD, the sysctl TCP connection, it is advisable to nullify the effects interface [5] provides a way of enabling or disabling the of the host cache. This can be easily achieved by extension and any applicable configuration variables. For changing “TCP HOSTCACHE PRUNE” to, for exam- the context of the following discussion unless explicitly ple, 5 seconds, recompiling the kernel, and then setting stated otherwise, enabling a sysctl variable means setting net.inet.tcp.hostcache.expire to 1. the variable to a value of “1”, and disabling means setting This will ensure all cache entries are removed within the variable to a value of “0”. For example, to enable 5 seconds of the cache entry being created at the termi- the TCP SACK extension, you would run the following nation of the connection. It is then simply a matter of command in a shell: ensuring you wait at least 5 seconds between test runs sysctl net.inet.tcp.sack.enable=1 to ensure the host cache is not affecting results. If this The most relevant FreeBSD sysctl variables that affect is too long a wait, you can decrease the time between the TCP stack and their default values are shown in checks even further. Listing 2. During our investigation of the affects of the host The full range of sysctl variables affecting FreeBSD’s cache on connections, we uncovered a quirk in the TCP stack can be found by running the following com- FreeBSD 6.2-RELEASE TCP stack. When a connection mand in a shell: is made to a new host (one for which no host cache sysctl -a | grep tcp entry exists), and the RFC3390 TCP configuration op- net.inet.tcp.sack.enable enables selective acknowledg- tion is enabled (see section II-B), the initial congestion ments [6], [7] and [8]. Enabling SACK does not guar- window should be, and is in fact set to 4380 bytes, as antee it will be used with all TCP connections, as it is recommended in RFC3390. However, when a host cache a negotiated option that both sides must support. It is entry does exist, the initial congestion window is set by advised that this variable be enabled. a different piece of code. net.inet.tcp.rfc1323 enables support for the window This piece of code is supposed to use the congestion scaling TCP extension [9]. This should be enabled to window value from the host cache to seed the congestion facilitate high bandwidth transfers. As with SACK, this CAIA Technical Report 070717B July 2007 page 2 of 6 Listing 2 reduced throughput as a result of delayed ACKing if net.inet.tcp.sack.enable: 1 non-zero packet loss is present. This behaviour occurs net.inet.tcp.rfc1323: 1 if the connection’s congestion window ever becomes net.inet.tcp.rfc3042: 1 equivalent to 1 segment size. This can occur if there is no net.inet.tcp.rfc3390: 1 data in flight after exiting fast recovery mode or during net.inet.tcp.slowstart flightsize: 1 initial startup of the connection. A congestion window of net.inet.tcp.local slowstart flightsize: 4 1 segment will result in the sending host sending only 1 net.inet.tcp.delayed ack: 1 segment, which will not be ACKed by the receiver using net.inet.tcp.delacktime: 100ms delayed ACKs until the delayed ACK timer expires.
Load more

Recommended publications
  • Freenas® 11.0 User Guide
    FreeNAS® 11.0 User Guide June 2017 Edition FreeNAS® IS © 2011-2017 iXsystems FreeNAS® AND THE FreeNAS® LOGO ARE REGISTERED TRADEMARKS OF iXsystems FreeBSD® IS A REGISTERED TRADEMARK OF THE FreeBSD Foundation WRITTEN BY USERS OF THE FreeNAS® network-attached STORAGE OPERATING system. VERSION 11.0 CopYRIGHT © 2011-2017 iXsystems (https://www.ixsystems.com/) CONTENTS WELCOME....................................................1 TYPOGRAPHIC Conventions...........................................2 1 INTRODUCTION 3 1.1 NeW FeaturES IN 11.0..........................................3 1.2 HarDWARE Recommendations.....................................4 1.2.1 RAM...............................................5 1.2.2 The OperATING System DeVICE.................................5 1.2.3 StorAGE Disks AND ContrOLLERS.................................6 1.2.4 Network INTERFACES.......................................7 1.3 Getting Started WITH ZFS........................................8 2 INSTALLING AND UpgrADING 9 2.1 Getting FreeNAS® ............................................9 2.2 PrEPARING THE Media.......................................... 10 2.2.1 On FreeBSD OR Linux...................................... 10 2.2.2 On WindoWS.......................................... 11 2.2.3 On OS X............................................. 11 2.3 Performing THE INSTALLATION....................................... 12 2.4 INSTALLATION TROUBLESHOOTING...................................... 18 2.5 UpgrADING................................................ 19 2.5.1 Caveats:............................................
    [Show full text]
  • Introduction to Debugging the Freebsd Kernel
    Introduction to Debugging the FreeBSD Kernel John H. Baldwin Yahoo!, Inc. Atlanta, GA 30327 [email protected], http://people.FreeBSD.org/˜jhb Abstract used either directly by the user or indirectly via other tools such as kgdb [3]. Just like every other piece of software, the The Kernel Debugging chapter of the FreeBSD kernel has bugs. Debugging a ker- FreeBSD Developer’s Handbook [4] covers nel is a bit different from debugging a user- several details already such as entering DDB, land program as there is nothing underneath configuring a system to save kernel crash the kernel to provide debugging facilities such dumps, and invoking kgdb on a crash dump. as ptrace() or procfs. This paper will give a This paper will not cover these topics. In- brief overview of some of the tools available stead, it will demonstrate some ways to use for investigating bugs in the FreeBSD kernel. FreeBSD’s kernel debugging tools to investi- It will cover the in-kernel debugger DDB and gate bugs. the external debugger kgdb which is used to perform post-mortem analysis on kernel crash dumps. 2 Kernel Crash Messages 1 Introduction The first debugging service the FreeBSD kernel provides is the messages the kernel prints on the console when the kernel crashes. When a userland application encounters a When the kernel encounters an invalid condi- bug the operating system provides services for tion (such as an assertion failure or a memory investigating the bug. For example, a kernel protection violation) it halts execution of the may save a copy of the a process’ memory current thread and enters a “panic” state also image on disk as a core dump.
    [Show full text]
  • Network Layer 2
    Network Layer Topics • Network service models • Datagrams (packets), virtual circuits • IP (Internet Protocol) • Internetworking • Forwarding (Longest Matching Prefix) • Helpers: ARP and DHCP • Fragmentation and MTU discovery • Errors: ICMP (traceroute!) • IPv6, scaling IP to the world • NAT, and “middleboxs” • Routing Algorithms CSE 461 University of Washington 2 Dynamic Host Configuration Protocol (DHCP) Bootstrapping •Problem: • A node wakes up for the first time … • What is its IP address? What’s the IP address of its router? • At least Ethernet address is on NIC What’s my IP? CSE 461 University of Washington 4 Bootstrapping 1. Manual configuration (old days) • Can’t be factory set, depends on use 2. DHCP: Automatically configure addresses • Shifts burden from users to IT folk What’s my IP? Use A.B.C.D CSE 461 University of Washington 5 DHCP •DHCP (Dynamic Host Configuration Protocol), from 1993, widely used •It leases IP address to nodes •Provides other parameters too • Network prefix • Address of local router • DNS server, time server, etc. CSE 461 University of Washington 6 DHCP Protocol Stack •DHCP is a client-server application • Uses UDP ports 67, 68 DHCP UDP IP Ethernet CSE 461 University of Washington 7 DHCP Addressing •Bootstrap issue: • How does node send a message to DHCP server before it is configured? •Answer: • Node sends broadcast messages that delivered to all nodes on the network • Broadcast address is all 1s • IP (32 bit): 255.255.255.255 • Ethernet/MAC (48 bit): ff:ff:ff:ff:ff:ff CSE 461 University of Washington
    [Show full text]
  • BSD UNIX Toolbox: 1000+ Commands for Freebsd, Openbsd and Netbsd Christopher Negus, Francois Caen
    To purchase this product, please visit https://www.wiley.com/en-bo/9780470387252 BSD UNIX Toolbox: 1000+ Commands for FreeBSD, OpenBSD and NetBSD Christopher Negus, Francois Caen E-Book 978-0-470-38725-2 April 2008 $16.99 DESCRIPTION Learn how to use BSD UNIX systems from the command line with BSD UNIX Toolbox: 1000+ Commands for FreeBSD, OpenBSD and NetBSD. Learn to use BSD operation systems the way the experts do, by trying more than 1,000 commands to find and obtain software, monitor system health and security, and access network resources. Apply your newly developed skills to use and administer servers and desktops running FreeBSD, OpenBSD, NetBSD, or any other BSD variety. Become more proficient at creating file systems, troubleshooting networks, and locking down security. ABOUT THE AUTHOR Christopher Negus served for eight years on development teams for the UNIX operating system at the AT&T labs, where UNIX was created and developed. He also worked with Novell on UNIX and UnixWare development. Chris is the author of the bestselling Fedora and Red Hat Linux Bible series, Linux Toys II, Linux Troubleshooting Bible, and Linux Bible 2008 Edition. Francois Caen hosts and manages business application infrastructures through his company Turbosphere LLC. As an open- source advocate, he has lectured on OSS network management and Internet services, and served as president of the Tacoma Linux User Group. He is a Red Hat Certified Engineer (RHCE). To purchase this product, please visit https://www.wiley.com/en-bo/9780470387252.
    [Show full text]
  • Tigersharc DSP Hardware Specification, Revision 1.0.2, Direct Memory Access
    7 DIRECT MEMORY ACCESS Figure 7-0. Table 7-0. Listing 7-0. Overview Direct Memory Access (DMA) is a mechanism for transferring data with- out core being involved. The TigerSHARC® DSP’s on-chip DMA controller relieves the core processor of the burden of moving data between internal memory and an external device, external memory, or between link ports and internal or external memory. The fully-integrated DMA controller allows the TigerSHARC® DSP core processor, or an external device, to specify data transfer operations and return to normal processing while the DMA controller carries out the data transfers in the background. The TigerSHARC® DSP DMA competes with other masters for internal memory access. For more information, see “Architecture and Microarchi- tecture Overview” on page 6-7. This conflict is minimized due to the large internal memory bandwidth that is available. The DMA includes 14 DMA channels, four of which are dedicated to external memory devices, eight to link ports, and two to AutoDMA registers. TigerSHARC DSP Hardware Specification 7 - 1 Overview Figure 7-1 shows a block diagram of the TigerSHARC® DSP’s DMA controller. TRANSMITTER RECEIVER TCB TCB REGISTERS REGISTERS Internal DMA DMA CONTROLLER Bus Requests Interface Figure 7-1. DMA Block Diagram Data Transfers — General Information The DMA controller can perform several types of data transfers: • Internal memory ⇒ external memory and memory-mapped periph- erals • Internal memory ⇒ internal memory of other TigerSHARC® DSPs residing on the cluster bus • Internal memory ⇒ host processor • Internal memory ⇒ link port I/O • External memory ⇒ external peripherals 7 - 2 TigerSHARC DSP Hardware Specification Direct Memory Access • External memory ⇒ internal memory • External memory ⇒ link port I/O • Link port I/O ⇒ internal memory • Link port I/O ⇒ external memory • Cluster bus master via AutoDMA registers ⇒ internal memory Internal-to-internal memory transfers are not directly supported.
    [Show full text]
  • Performance, Scalability on the Server Side
    Performance, Scalability on the Server Side John VanDyk Presented at Des Moines Web Geeks 9/21/2009 Who is this guy? History • Apple // • Macintosh • Windows 3.1- Server 2008R2 • Digital Unix (Tru64) • Linux (primarily RHEL) • FreeBSD Systems Iʼve worked with over the years. Languages • Perl • Userland Frontier™ • Python • Java • Ruby • PHP Languages Iʼve worked with over the years (Userland Frontier™ʼs integrated language is UserTalk™) Open source developer since 2000 Perl/Python/PHP MySQL Apache Linux The LAMP stack. Time to Serve Request Number of Clients Performance vs. scalability. network in network out RAM CPU Storage These are the basic laws of physics. All bottlenecks are caused by one of these four resources. Disk-bound •To o l s •iostat •vmstat Determine if you are disk-bound by measuring throughput. vmstat (BSD) procs memory page disk faults cpu r b w avm fre flt re pi po fr sr tw0 in sy cs us sy id 0 2 0 799M 842M 27 0 0 0 12 0 23 344 2906 1549 1 1 98 3 3 0 869M 789M 5045 0 0 0 406 0 10 1311 17200 5301 12 4 84 3 5 0 923M 794M 5219 0 0 0 5178 0 27 1825 21496 6903 35 8 57 1 2 0 931M 784M 909 0 0 0 146 0 12 955 9157 3570 8 4 88 blocked plenty of RAM, idle processes no swapping CPUs A disk-bound FreeBSD machine. b = blocked for resources fr = pages freed/sec cs = context switches avm = active virtual pages in = interrupts flt = memory page faults sy = system calls per interval vmstat (RHEL5) # vmstat -S M 5 25 procs ---------memory-------- --swap- ---io--- --system- -----cpu------ r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 0 1301 194 5531 0 0 0 29 1454 2256 24 20 56 0 0 3 0 0 1257 194 5531 0 0 0 40 2087 2336 34 27 39 0 0 2 0 0 1183 194 5531 0 0 0 53 1658 2763 33 28 39 0 0 0 0 0 1344 194 5531 0 0 0 34 1807 2125 29 19 52 0 0 no blocked busy but not processes overloaded CPU in = interrupts/sec cs = context switches/sec wa = time waiting for I/O Solving disk bottlenecks • Separate spindles (logs and databases) • Get rid of atime updates! • Minimize writes • Move temp writes to /dev/shm Overview of what weʼre about to dive into.
    [Show full text]
  • Xcode Package from App Store
    KH Computational Physics- 2016 Introduction Setting up your computing environment Installation • MAC or Linux are the preferred operating system in this course on scientific computing. • Windows can be used, but the most important programs must be installed – python : There is a nice package ”Enthought Python Distribution” http://www.enthought.com/products/edudownload.php – C++ and Fortran compiler – BLAS&LAPACK for linear algebra – plotting program such as gnuplot Kristjan Haule, 2016 –1– KH Computational Physics- 2016 Introduction Software for this course: Essentials: • Python, and its packages in particular numpy, scipy, matplotlib • C++ compiler such as gcc • Text editor for coding (for example Emacs, Aquamacs, Enthought’s IDLE) • make to execute makefiles Highly Recommended: • Fortran compiler, such as gfortran or intel fortran • BLAS& LAPACK library for linear algebra (most likely provided by vendor) • open mp enabled fortran and C++ compiler Useful: • gnuplot for fast plotting. • gsl (Gnu scientific library) for implementation of various scientific algorithms. Kristjan Haule, 2016 –2– KH Computational Physics- 2016 Introduction Installation on MAC • Install Xcode package from App Store. • Install ‘‘Command Line Tools’’ from Apple’s software site. For Mavericks and lafter, open Xcode program, and choose from the menu Xcode -> Open Developer Tool -> More Developer Tools... You will be linked to the Apple page that allows you to access downloads for Xcode. You wil have to register as a developer (free). Search for the Xcode Command Line Tools in the search box in the upper left. Download and install the correct version of the Command Line Tools, for example for OS ”El Capitan” and Xcode 7.2, Kristjan Haule, 2016 –3– KH Computational Physics- 2016 Introduction you need Command Line Tools OS X 10.11 for Xcode 7.2 Apple’s Xcode contains many libraries and compilers for Mac systems.
    [Show full text]
  • The Dragonflybsd Operating System
    1 The DragonFlyBSD Operating System Jeffrey M. Hsu, Member, FreeBSD and DragonFlyBSD directories with slightly over 8 million lines of code, 2 million Abstract— The DragonFlyBSD operating system is a fork of of which are in the kernel. the highly successful FreeBSD operating system. Its goals are to The project has a number of resources available to the maintain the high quality and performance of the FreeBSD 4 public, including an on-line CVS repository with mirror sites, branch, while exploiting new concepts to further improve accessible through the web as well as the cvsup service, performance and stability. In this paper, we discuss the motivation for a new BSD operating system, new concepts being mailing list forums, and a bug submission system. explored in the BSD context, the software infrastructure put in place to explore these concepts, and their application to the III. MOTIVATION network subsystem in particular. A. Technical Goals Index Terms— Message passing, Multiprocessing, Network The DragonFlyBSD operating system has several long- operating systems, Protocols, System software. range technical goals that it hopes to accomplish within the next few years. The first goal is to add lightweight threads to the BSD kernel. These threads are lightweight in the sense I. INTRODUCTION that, while user processes have an associated thread and a HE DragonFlyBSD operating system is a fork of the process context, kernel processes are pure threads with no T highly successful FreeBSD operating system. Its goals are process context. The threading model makes several to maintain the high quality and performance of the FreeBSD guarantees with respect to scheduling to ensure high 4 branch, while exploring new concepts to further improve performance and simplify reasoning about concurrency.
    [Show full text]
  • BSD UNIX Toolbox 1000+ Commands for Freebsd, Openbsd
    76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page iii BSD UNIX® TOOLBOX 1000+ Commands for FreeBSD®, OpenBSD, and NetBSD®Power Users Christopher Negus François Caen 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page ii 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page i BSD UNIX® TOOLBOX 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page ii 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page iii BSD UNIX® TOOLBOX 1000+ Commands for FreeBSD®, OpenBSD, and NetBSD®Power Users Christopher Negus François Caen 76034ffirs.qxd:Toolbox 4/2/08 12:50 PM Page iv BSD UNIX® Toolbox: 1000+ Commands for FreeBSD®, OpenBSD, and NetBSD® Power Users Published by Wiley Publishing, Inc. 10475 Crosspoint Boulevard Indianapolis, IN 46256 www.wiley.com Copyright © 2008 by Wiley Publishing, Inc., Indianapolis, Indiana Published simultaneously in Canada ISBN: 978-0-470-37603-4 Manufactured in the United States of America 10 9 8 7 6 5 4 3 2 1 Library of Congress Cataloging-in-Publication Data is available from the publisher. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, 222 Rosewood Drive, Danvers, MA 01923, (978) 750-8400, fax (978) 646-8600. Requests to the Publisher for permis- sion should be addressed to the Legal Department, Wiley Publishing, Inc., 10475 Crosspoint Blvd., Indianapolis, IN 46256, (317) 572-3447, fax (317) 572-4355, or online at http://www.wiley.com/go/permissions.
    [Show full text]
  • The GINI Router
    The GINI Router: A Routing Element for User-level Micro Internet by Weiling Xu DEPARTMENT OF COMPUTER SCIENCE MCGILL UNIVERSITY, MONTREAL JUNE,2004 A THESIS SUBMITTED TO MCGILL UNIVERSITY IN PARTIAL FULFILMENT OF THE REQUlREMENTS OF THE DEGREE OF MASTER OF SCIENCE © Weiling Xu 2004 Library and Bibliothèque et 1+1 Archives Canada Archives Canada Published Heritage Direction du Branch Patrimoine de l'édition 395 Wellington Street 395, rue Wellington Ottawa ON K1A ON4 Ottawa ON K1A ON4 Canada Canada Your file Votre référence ISBN: 0-494-06476-5 Our file Notre référence ISBN: 0-494-06476-5 NOTICE: AVIS: The author has granted a non­ L'auteur a accordé une licence non exclusive exclusive license allowing Library permettant à la Bibliothèque et Archives and Archives Canada to reproduce, Canada de reproduire, publier, archiver, publish, archive, preserve, conserve, sauvegarder, conserver, transmettre au public communicate to the public by par télécommunication ou par l'Internet, prêter, telecommunication or on the Internet, distribuer et vendre des thèses partout dans loan, distribute and sell th es es le monde, à des fins commerciales ou autres, worldwide, for commercial or non­ sur support microforme, papier, électronique commercial purposes, in microform, et/ou autres formats. paper, electronic and/or any other formats. The author retains copyright L'auteur conserve la propriété du droit d'auteur ownership and moral rights in et des droits moraux qui protège cette thèse. this thesis. Neither the thesis Ni la thèse ni des extraits substantiels de nor substantial extracts from it celle-ci ne doivent être imprimés ou autrement may be printed or otherwise reproduits sans son autorisation.
    [Show full text]
  • Interesting Things You Didn't Know You Could Do With
    Interesting Things You Didn’t Know You Could Do With ZFS Allan Jude -- ScaleEngine Inc. [email protected] twitter: @allanjude Introduction Allan Jude ● 13 Years as FreeBSD Server Admin ● FreeBSD src/doc committer (focus: ZFS, bhyve, ucl, xo) ● Co-Author of “FreeBSD Mastery: ZFS” and upcoming “FreeBSD Mastery: Advanced ZFS” with M. W. Lucas ● Architect of the ScaleEngine CDN (HTTP and Video) ● Host of BSDNow.tv & TechSNAP.tv Podcasts ● Use ZFS for large collections of videos, extremely large website caches, mirrors of PC-BSD pkgs and RaspBSD ● Single Handedly Manage Over 1000TB of ZFS Storage The Power of ZFS ● Integrated Redundancy (Mirroring, RAID-Z) ● Data Integrity Checking (Checksums, Scrub) ● Pooled Storage (Hot Add Disks) ● Multi-Level Cache (ARC, L2ARC, SLOG) ● Copy-on-Write (no fsck) ● Snapshots and Clones ● Quotas and Reservations ● Transparent Compression (LZ4, GZIP1-9) ● Incremental Replication (zfs send/recv) ● Datasets with Individual Inherited Properties ● Custom Properties ● Fine Grained Delegation Applying That Power ZFS has many features, but how can I use them to solve my problems? ZFS has a very well designed command line user interface, making it very easy for a sysadmin to perform common tasks (add more storage, create new datasets, change settings and properties), accomplish things that were not possible before, as well as extract a great deal more information from the storage system. ZFS Was Meant To Be Scripted # zfs list -Hp -r -o name,refer,logicalreferenced sestore5/mysql02 22001288628 24331078144 sestore5/omicron
    [Show full text]
  • The Complete Freebsd
    The Complete FreeBSD® If you find errors in this book, please report them to Greg Lehey <grog@Free- BSD.org> for inclusion in the errata list. The Complete FreeBSD® Fourth Edition Tenth anniversary version, 24 February 2006 Greg Lehey The Complete FreeBSD® by Greg Lehey <[email protected]> Copyright © 1996, 1997, 1999, 2002, 2003, 2006 by Greg Lehey. This book is licensed under the Creative Commons “Attribution-NonCommercial-ShareAlike 2.5” license. The full text is located at http://creativecommons.org/licenses/by-nc-sa/2.5/legalcode. You are free: • to copy, distribute, display, and perform the work • to make derivative works under the following conditions: • Attribution. You must attribute the work in the manner specified by the author or licensor. • Noncommercial. You may not use this work for commercial purposes. This clause is modified from the original by the provision: You may use this book for commercial purposes if you pay me the sum of USD 20 per copy printed (whether sold or not). You must also agree to allow inspection of printing records and other material necessary to confirm the royalty sums. The purpose of this clause is to make it attractive to negotiate sensible royalties before printing. • Share Alike. If you alter, transform, or build upon this work, you may distribute the resulting work only under a license identical to this one. • For any reuse or distribution, you must make clear to others the license terms of this work. • Any of these conditions can be waived if you get permission from the copyright holder. Your fair use and other rights are in no way affected by the above.
    [Show full text]