CS 416: Operating Systems Design March 25, 2015
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Storage Administration Guide Storage Administration Guide SUSE Linux Enterprise Server 12 SP4
SUSE Linux Enterprise Server 12 SP4 Storage Administration Guide Storage Administration Guide SUSE Linux Enterprise Server 12 SP4 Provides information about how to manage storage devices on a SUSE Linux Enterprise Server. Publication Date: September 24, 2021 SUSE LLC 1800 South Novell Place Provo, UT 84606 USA https://documentation.suse.com Copyright © 2006– 2021 SUSE LLC and contributors. All rights reserved. Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or (at your option) version 1.3; with the Invariant Section being this copyright notice and license. A copy of the license version 1.2 is included in the section entitled “GNU Free Documentation License”. For SUSE trademarks, see https://www.suse.com/company/legal/ . All other third-party trademarks are the property of their respective owners. Trademark symbols (®, ™ etc.) denote trademarks of SUSE and its aliates. Asterisks (*) denote third-party trademarks. All information found in this book has been compiled with utmost attention to detail. However, this does not guarantee complete accuracy. Neither SUSE LLC, its aliates, the authors nor the translators shall be held liable for possible errors or the consequences thereof. Contents About This Guide xii 1 Available Documentation xii 2 Giving Feedback xiv 3 Documentation Conventions xiv 4 Product Life Cycle and Support xvi Support Statement for SUSE Linux Enterprise Server xvii • Technology Previews xviii I FILE SYSTEMS AND MOUNTING 1 1 Overview -
Membrane: Operating System Support for Restartable File Systems Swaminathan Sundararaman, Sriram Subramanian, Abhishek Rajimwale, Andrea C
Membrane: Operating System Support for Restartable File Systems Swaminathan Sundararaman, Sriram Subramanian, Abhishek Rajimwale, Andrea C. Arpaci-Dusseau, Remzi H. Arpaci-Dusseau, Michael M. Swift Computer Sciences Department, University of Wisconsin, Madison Abstract and most complex code bases in the kernel. Further, We introduce Membrane, a set of changes to the oper- file systems are still under active development, and new ating system to support restartable file systems. Mem- ones are introduced quite frequently. For example, Linux brane allows an operating system to tolerate a broad has many established file systems, including ext2 [34], class of file system failures and does so while remain- ext3 [35], reiserfs [27], and still there is great interest in ing transparent to running applications; upon failure, the next-generation file systems such as Linux ext4 and btrfs. file system restarts, its state is restored, and pending ap- Thus, file systems are large, complex, and under develop- plication requests are serviced as if no failure had oc- ment, the perfect storm for numerous bugs to arise. curred. Membrane provides transparent recovery through Because of the likely presence of flaws in their imple- a lightweight logging and checkpoint infrastructure, and mentation, it is critical to consider how to recover from includes novel techniques to improve performance and file system crashes as well. Unfortunately, we cannot di- correctness of its fault-anticipation and recovery machin- rectly apply previous work from the device-driver litera- ery. We tested Membrane with ext2, ext3, and VFAT. ture to improving file-system fault recovery. File systems, Through experimentation, we show that Membrane in- unlike device drivers, are extremely stateful, as they man- duces little performance overhead and can tolerate a wide age vast amounts of both in-memory and persistent data; range of file system crashes. -
Ext4 File System and Crash Consistency
1 Ext4 file system and crash consistency Changwoo Min 2 Summary of last lectures • Tools: building, exploring, and debugging Linux kernel • Core kernel infrastructure • Process management & scheduling • Interrupt & interrupt handler • Kernel synchronization • Memory management • Virtual file system • Page cache and page fault 3 Today: ext4 file system and crash consistency • File system in Linux kernel • Design considerations of a file system • History of file system • On-disk structure of Ext4 • File operations • Crash consistency 4 File system in Linux kernel User space application (ex: cp) User-space Syscalls: open, read, write, etc. Kernel-space VFS: Virtual File System Filesystems ext4 FAT32 JFFS2 Block layer Hardware Embedded Hard disk USB drive flash 5 What is a file system fundamentally? int main(int argc, char *argv[]) { int fd; char buffer[4096]; struct stat_buf; DIR *dir; struct dirent *entry; /* 1. Path name -> inode mapping */ fd = open("/home/lkp/hello.c" , O_RDONLY); /* 2. File offset -> disk block address mapping */ pread(fd, buffer, sizeof(buffer), 0); /* 3. File meta data operation */ fstat(fd, &stat_buf); printf("file size = %d\n", stat_buf.st_size); /* 4. Directory operation */ dir = opendir("/home"); entry = readdir(dir); printf("dir = %s\n", entry->d_name); return 0; } 6 Why do we care EXT4 file system? • Most widely-deployed file system • Default file system of major Linux distributions • File system used in Google data center • Default file system of Android kernel • Follows the traditional file system design 7 History of file system design 8 UFS (Unix File System) • The original UNIX file system • Design by Dennis Ritche and Ken Thompson (1974) • The first Linux file system (ext) and Minix FS has a similar layout 9 UFS (Unix File System) • Performance problem of UFS (and the first Linux file system) • Especially, long seek time between an inode and data block 10 FFS (Fast File System) • The file system of BSD UNIX • Designed by Marshall Kirk McKusick, et al. -
Z/OS Distributed File Service Zseries File System Implementation Z/OS V1R13
Front cover z/OS Distributed File Service zSeries File System Implementation z/OS V1R13 Defining and installing a zSeries file system Performing backup and recovery, sysplex sharing Migrating from HFS to zFS Paul Rogers Robert Hering ibm.com/redbooks International Technical Support Organization z/OS Distributed File Service zSeries File System Implementation z/OS V1R13 October 2012 SG24-6580-05 Note: Before using this information and the product it supports, read the information in “Notices” on page xiii. Sixth Edition (October 2012) This edition applies to version 1 release 13 modification 0 of IBM z/OS (product number 5694-A01) and to all subsequent releases and modifications until otherwise indicated in new editions. © Copyright International Business Machines Corporation 2010, 2012. All rights reserved. Note to U.S. Government Users Restricted Rights -- Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Notices . xiii Trademarks . xiv Preface . .xv The team who wrote this book . .xv Now you can become a published author, too! . xvi Comments welcome. xvi Stay connected to IBM Redbooks . xvi Chapter 1. zFS file systems . 1 1.1 zSeries File System introduction. 2 1.2 Application programming interfaces . 2 1.3 zFS physical file system . 3 1.4 zFS colony address space . 4 1.5 zFS supports z/OS UNIX ACLs. 4 1.6 zFS file system aggregates. 5 1.6.1 Compatibility mode aggregates. 5 1.6.2 Multifile system aggregates. 6 1.7 Metadata cache. 7 1.8 zFS file system clones . 7 1.8.1 Backup file system . 8 1.9 zFS log files. -
Configuring and Managing the Network File System
ch33.fm Page 639 Saturday, April 29, 2000 1:41 AM THIRTY-THREE 33 Configuring and Managing the Network File System LChapter Syllabus The Network File System (NFS) is used to share files and directories over a network. It is an RPC- 33.1 NFS Concepts based system and works in the client-server model. The NFS server makes some of its file sys- 33.2 Configuring an NFS Server tems shareable with other systems on a network. The NFS client mounts shared file systems from 33.3 Configuring an NFS Client the server to its local mount points. Users of the client machines can use NFS-mounted file systems 33.4 NFS Daemons just like the local file systems. NFS support is available on many platforms including personal 33.5 Troubleshooting computers. On UNIX systems, this has become a de facto standard and provides a transparent way for sharing files. When used in combination with NIS, it facilitates users’ logging in from any machine on the network and finding the same environment, home directories, and mailboxes. NFS is used to save disk space in a number of ways. All files that are static in nature can be shared on a network. These files include applica- tion directories under /opt and operating system files under the /usr directory. The files that are 639 ch33.fm Page 640 Saturday, April 29, 2000 1:41 AM 640 Chapter 33 • Configuring and Managing the Network File System shared by individual users are users’ home directories and mail- boxes. The directories that contain configuration files or log files are usually not shared. -
AMD Alchemy™ Processors Building a Root File System for Linux® Incorporating Memory Technology Devices
AMD Alchemy™ Processors Building a Root File System for Linux® Incorporating Memory Technology Devices 1.0 Scope This document outlines a step-by-step process for building and deploying a Flash-based root file system for Linux® on an AMD Alchemy™ processor-based development board, using an approach that incorporates Memory Technology Devices (MTDs) with the JFFS2 file system. Note: This document describes creating a root file system on NOR Flash memory devices, and does not apply to NAND Flash devices. 1.1 Journaling Flash File System JFFS2 is the second generation of the Journaling Flash File System (JFFS). This file system provides a crash-safe and powerdown-safe Linux file system for use with Flash memory devices. The home page for the JFFS project is located at http://developer.axis.com/software/jffs. 1.2 Memory Technology Device The MTD subsystem provides a generic Linux driver for a wide range of memory devices, including Flash memory devices. This driver creates an abstracted device used by JFFS2 to interface to the actual Flash memory hardware. The home page for the MTD project is located at http://www.linux-mtd.infradead.org. 2.0 Building the Root File System Before being deployed to an AMD Alchemy platform, the file system must first be built on an x86 Linux host PC. The pri- mary concern when building a Flash-based root file system is often the size of the image. The file system must be designed so that it fits within the available space of the Flash memory, with enough extra space to accommodate any runtime-created files, such as temporary or log files. -
Filesystem Considerations for Embedded Devices ELC2015 03/25/15
Filesystem considerations for embedded devices ELC2015 03/25/15 Tristan Lelong Senior embedded software engineer Filesystem considerations ABSTRACT The goal of this presentation is to answer a question asked by several customers: which filesystem should you use within your embedded design’s eMMC/SDCard? These storage devices use a standard block interface, compatible with traditional filesystems, but constraints are not those of desktop PC environments. EXT2/3/4, BTRFS, F2FS are the first of many solutions which come to mind, but how do they all compare? Typical queries include performance, longevity, tools availability, support, and power loss robustness. This presentation will not dive into implementation details but will instead summarize provided answers with the help of various figures and meaningful test results. 2 TABLE OF CONTENTS 1. Introduction 2. Block devices 3. Available filesystems 4. Performances 5. Tools 6. Reliability 7. Conclusion Filesystem considerations ABOUT THE AUTHOR • Tristan Lelong • Embedded software engineer @ Adeneo Embedded • French, living in the Pacific northwest • Embedded software, free software, and Linux kernel enthusiast. 4 Introduction Filesystem considerations Introduction INTRODUCTION More and more embedded designs rely on smart memory chips rather than bare NAND or NOR. This presentation will start by describing: • Some context to help understand the differences between NAND and MMC • Some typical requirements found in embedded devices designs • Potential filesystems to use on MMC devices 6 Filesystem considerations Introduction INTRODUCTION Focus will then move to block filesystems. How they are supported, what feature do they advertise. To help understand how they compare, we will present some benchmarks and comparisons regarding: • Tools • Reliability • Performances 7 Block devices Filesystem considerations Block devices MMC, EMMC, SD CARD Vocabulary: • MMC: MultiMediaCard is a memory card unveiled in 1997 by SanDisk and Siemens based on NAND flash memory. -
GPFS Policy Engine
General Parallel File System Version 4 Release 1 Administration and Programming Reference SA23-1452-00 General Parallel File System Version 4 Release 1 Administration and Programming Reference SA23-1452-00 Note Before using this information and the product it supports, read the information in “Notices” on page 655. This edition applies to version 4 release 1 modification 0 of the following products, and to all subsequent releases and modifications until otherwise indicated in new editions: v IBM General Parallel File System ordered through Passport Advantage® (product number 5725-Q01) v IBM General Parallel File System ordered through AAS/eConfig (product number 5641-GPF) v IBM General Parallel File System ordered through HVEC/Xcel (product number 5641-GP6, 5641-GP7, or 5641-GP8) Significant changes or additions to the text and illustrations are indicated by a vertical line (|) to the left of the change. IBM welcomes your comments; see the topic “How to send your comments” on page xii. When you send information to IBM, you grant IBM a nonexclusive right to use or distribute the information in any way it believes appropriate without incurring any obligation to you. © Copyright IBM Corporation 2014. US Government Users Restricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp. Contents Tables ...............vii Backing up a file system using the mmbackup command ..............34 About this information ........ix Backing up a file system using the GPFS policy engine ...............40 Prerequisite and related information ......x Backing up file system configuration information 40 Conventions used in this information ......xi Using APIs to develop backup applications. -
F2punifycr: a Flash-Friendly Persistent Burst-Buffer File System
F2PUnifyCR: A Flash-friendly Persistent Burst-Buffer File System ThanOS Department of Computer Science Florida State University Tallahassee, United States I. ABSTRACT manifold depending on the workloads it is handling for With the increased amount of supercomputing power, applications. In order to leverage the capabilities of burst it is now possible to work with large scale data that buffers to the utmost level, it is very important to have a pose a continuous opportunity for exascale computing standardized software interface across systems. It has to that puts immense pressure on underlying persistent data deal with an immense amount of data during the runtime storage. Burst buffers, a distributed array of node-local of the applications. persistent flash storage devices deployed on most of Using node-local burst buffer can achieve scalable the leardership supercomputers, are means to efficiently write bandwidth as it lets each process write to the handling the bursty I/O invoked through cutting-edge local flash drive, but when the files are shared across scientific applications. In order to manage these burst many processes, it puts the management of metadata buffers, many ephemeral user level file system solutions, and object data of the files under huge challenge. In like UnifyCR, are present in the research and industry order to handle all the challenges posed by the bursty arena. Because of the intrinsic nature of the flash devices and random I/O requests by the Scientific Applica- due to background processing overhead, like Garbage tions running on leadership Supercomputing clusters, Collection, peak write bandwidth is hard to get. -
Managing Network File Systems in Oracle® Solaris 11.4
Managing Network File Systems in ® Oracle Solaris 11.4 Part No: E61004 August 2021 Managing Network File Systems in Oracle Solaris 11.4 Part No: E61004 Copyright © 2002, 2021, Oracle and/or its affiliates. This software and related documentation are provided under a license agreement containing restrictions on use and disclosure and are protected by intellectual property laws. Except as expressly permitted in your license agreement or allowed by law, you may not use, copy, reproduce, translate, broadcast, modify, license, transmit, distribute, exhibit, perform, publish, or display any part, in any form, or by any means. Reverse engineering, disassembly, or decompilation of this software, unless required by law for interoperability, is prohibited. The information contained herein is subject to change without notice and is not warranted to be error-free. If you find any errors, please report them to us in writing. If this is software or related documentation that is delivered to the U.S. Government or anyone licensing it on behalf of the U.S. Government, then the following notice is applicable: U.S. GOVERNMENT END USERS: Oracle programs (including any operating system, integrated software, any programs embedded, installed or activated on delivered hardware, and modifications of such programs) and Oracle computer documentation or other Oracle data delivered to or accessed by U.S. Government end users are "commercial computer software" or "commercial computer software documentation" pursuant to the applicable Federal Acquisition Regulation and agency-specific supplemental regulations. As such, the use, reproduction, duplication, release, display, disclosure, modification, preparation of derivative works, and/or adaptation of i) Oracle programs (including any operating system, integrated software, any programs embedded, installed or activated on delivered hardware, and modifications of such programs), ii) Oracle computer documentation and/or iii) other Oracle data, is subject to the rights and limitations specified in the license contained in the applicable contract. -
Foot Prints Feel the Freedom of Fedora!
The Fedora Project: Foot Prints Feel The Freedom of Fedora! RRaahhuull SSuunnddaarraamm SSuunnddaarraamm@@ffeeddoorraapprroojjeecctt..oorrgg FFrreeee ((aass iinn ssppeeeecchh aanndd bbeeeerr)) AAddvviiccee 101011:: KKeeeepp iitt iinntteerraaccttiivvee!! Credit: Based on previous Fedora presentations from Red Hat and various community members. Using the age old wisdom and Indian, Free software tradition of standing on the shoulders of giants. Who the heck is Rahul? ( my favorite part of this presentation) ✔ Self elected Fedora project monkey and noisemaker ✔ Fedora Project Board Member ✔ Fedora Ambassadors steering committee member. ✔ Fedora Ambassador for India.. ✔ Editor for Fedora weekly reports. ✔ Fedora Websites, Documentation and Bug Triaging projects volunteer and miscellaneous few grunt work. Agenda ● Red Hat Linux to Fedora & RHEL - Why? ● What is Fedora ? ● What is the Fedora Project ? ● Who is behind the Fedora Project ? ● Primary Principles. ● What are the Fedora projects? ● Features, Future – Fedora Core 5 ... The beginning: Red Hat Linux 1994-2003 ● Released about every 6 months ● More stable “ .2” releases about every 18 months ● Rapid innovation ● Problems with retail channel sales model ● Impossible to support long-term ● Community Participation: ● Upstream Projects ● Beta Team / Bug Reporting The big split: Fedora and RHEL Red Hat had two separate, irreconcilable goals: ● To innovate rapidly. To provide stability for the long-term ● Red Hat Enterprise Linux (RHEL) ● Stable and supported for 7 years plus. A platform for 3rd party standardization ● Free as in speech ● Fedora Project / Fedora Core ● Rapid releases of Fedora Core, every 6 months ● Space to innovate. Fedora Core in the tradition of Red Hat Linux (“ FC1 == RHL10” ) Free as in speech, free as in beer, free as in community support ● Built and sponsored by Red Hat ● ...with increased community contributions. -
YAFFS a NAND Flash Filesystem
Project Genesis Flash hardware YAFFS fundamentals Filesystem Details Embedded Use YAFFS A NAND flash filesystem Wookey [email protected] Aleph One Ltd Balloonboard.org Toby Churchill Ltd Embedded Linux Conference - Europe Linz Project Genesis Flash hardware YAFFS fundamentals Filesystem Details Embedded Use 1 Project Genesis 2 Flash hardware 3 YAFFS fundamentals 4 Filesystem Details 5 Embedded Use Project Genesis Flash hardware YAFFS fundamentals Filesystem Details Embedded Use Project Genesis TCL needed a reliable FS for NAND Charles Manning is the man Considered Smartmedia compatibile scheme (FAT+FTL) Considered JFFS2 Better than FTL High RAM use Slow boot times Project Genesis Flash hardware YAFFS fundamentals Filesystem Details Embedded Use History Decided to create ’YAFFS’ - Dec 2001 Working on NAND emulator - March 2002 Working on real NAND (Linux) - May 2002 WinCE version - Aug 2002 ucLinux use - Sept 2002 Linux rootfs - Nov 2002 pSOS version - Feb 2003 Shipping commercially - Early 2003 Linux 2.6 supported - Aug 2004 YAFFS2 - Dec 2004 Checkpointing - May 2006 Project Genesis Flash hardware YAFFS fundamentals Filesystem Details Embedded Use Flash primer - NOR vs NAND NOR flash NAND flash Access mode: Linear random access Page access Replaces: ROM Mass Storage Cost: Expensive Cheap Device Density: Low (64MB) High (1GB) Erase block 8k to 128K typical 32x512b / 64x2K pages size: Endurance: 100k to 1M erasures 10k to 100k erasures Erase time: 1second 2ms Programming: Byte by Byte, no limit on writes Page programming, must be erased before re-writing Data sense: Program byte to change 1s to 0s. Program page to change 1s to 0s. Erase block to change 0s to 1s Erase to change 0s to 1s Write Ordering: Random access programming Pages must be written sequen- tially within block Bad blocks: None when delivered, but will Bad blocks expected when deliv- wear out so filesystems should be ered.