Red Hat Enterprise Linux 5 Global Network Block Device Using GNBD with Red Hat Global File System Edition 3 Landmann
Red Hat Enterprise Linux 5 Global Network Block Device Using GNBD with Red Hat Global File System Edition 3 Landmann rlandmann@redhat.
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Table of Contents Table of Contents .Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .3. . . . . . . . . . 1. About T his Guide 3 2. Audience 3 3. Software Versions 3 4. Related Documentation 3 5. Feedback 4 6. Document Conventions 4 6.1. T ypographic Conventions 4 6.2. Pull-quote Conventions 6 6.3. Notes and Warnings 6 . . . . . . . . . 1. Chapter . . .Using . .
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Introduction Introduction 1. About This Guide T his book describes how to use Global Network Block Device (GNDB) with Global File System (GFS), including information about device-mapper multipath, GNDB driver and command usage, and running GFS on a GNBD server node. 2. Audience T his book is intended to be used by system administrators managing systems running the Linux operating system. It requires familiarity with Red Hat Enterprise Linux 5 and GFS file system administration. 3.
Red Hat Enterprise Linux 5 Global Network Block D evice Cluster Suite. Red Hat Cluster Suite documentation and other Red Hat documents are available in HT ML, PDF, and RPM versions on the Red Hat Enterprise Linux Documentation CD and online at http://www.redhat.com/docs/. 5. Feedback If you spot a typo, or if you have thought of a way to make this manual better, we would love to hear from you. Please submit a report in Bugzilla (http://bugzilla.redhat.com/bugzilla/) against the component rhcs.
Introduction Press Ctrl+Alt+F2 to switch to a virtual terminal. T he first example highlights a particular key to press. T he second example highlights a key combination: a set of three keys pressed simultaneously. If source code is discussed, class names, methods, functions, variable names and returned values mentioned within a paragraph will be presented as above, in m ono-spaced bold. For example: File-related classes include filesystem for file systems, file for files, and dir for directories.
Red Hat Enterprise Linux 5 Global Network Block D evice Publican is a DocBook publishing system. 6.2. Pull-quote Conventions T erminal output and source code listings are set off visually from the surrounding text.
Introduction Warning Warnings should not be ignored. Ignoring warnings will most likely cause data loss.
Red Hat Enterprise Linux 5 Global Network Block D evice Chapter 1. Using GNBD with Red Hat GFS GNBD (Global Network Block Device) provides block-level storage access over an Ethernet LAN. GNBD components run as a client in a GFS node and as a server in a GNBD server node. A GNBD server node exports block-level storage from its local storage (either directly attached storage or SAN storage) to a GFS node. T able 1.1, “GNBD Software Subsystem Components” summarizes the GNBD software subsystems components.
Chapter 2. Considerations for Using GNBD with D evice-Mapper Multipath Chapter 2. Considerations for Using GNBD with Device-Mapper Multipath GNBD with device-mapper multipath allows you to configure multiple GNBD server nodes (nodes that export GNBDs to GFS nodes) to provide redundant paths to the storage devices. T he GNBD server nodes, in turn, present multiple storage paths to GFS nodes via redundant GNBDs.
Red Hat Enterprise Linux 5 Global Network Block D evice Chapter 3. GNBD Driver and Command Usage T he Global Network Block Device (GNBD) driver allows a node to export its local storage as a GNBD over a network so that other nodes on the network can share the storage. Client nodes importing the GNBD use it like any other block device. Importing a GNBD on multiple clients forms a shared storage configuration through which GFS can be used. T he GNBD driver is implemented through the following components.
Chapter 3. GNBD D river and Command Usage Specifies an arbitrary name selected for the GNBD. It is used as the device name on GNBD clients. T his name must be unique among all GNBDs exported in a network. -o Export the device as read-only. -c Enable caching. Reads from the exported GNBD and takes advantage of the Linux page cache. By default, the gnbd_export command does not enable caching. Note When you configure GNBD servers with device-mapper multipath, do not specify the -c option.
Red Hat Enterprise Linux 5 Global Network Block D evice -U Command Gets the UID command. T he UID command is a command the gnbd_export command will run to get a Universal Identifier for the exported device. T he UID is necessary to use device-mapper multipath with GNBD. T he command must use the full path of any executeable that you wish to run. A command can contain the %M, %m or %n escape sequences.
Chapter 4. Running GFS on a GNBD Server Node Chapter 4. Running GFS on a GNBD Server Node You can run GFS on a GNBD server node, with some restrictions. In addition, running GFS on a GNBD server node reduces performance. T he following restrictions apply when running GFS on a GNBD server node. Important When running GFS on a GNBD server node you must follow the restrictions listed; otherwise, the GNBD server node will fail. 1.
Red Hat Enterprise Linux 5 Global Network Block D evice Revision History Revision 3-11.4 00 Rebuild with publican 4.0.0 2013-10-31 Rüdiger Landmann Revision 3-11 Rebuild for Publican 3.0 2012-07-18 Anthony T owns Revision 5.7-1 T hu Jul 21 2011 Resolves: #703610 Fixes minor typographical errors. Revision 1.
Revision History L Linux page caching, Linux Page Caching S software subsystem components, Using GNBD with Red Hat GFS 15
