Red Hat GFS 6.1 Release Notes
Copyright(c) 2005 Red Hat, Inc.
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November 3, 2005
Introduction
The following topics are covered in this document:
o Changes to GFS 6.1
o Important Notes
o Related Documentation
Changes to GFS 6.1
This section describes changes for GFS 6.1 and includes the following
information:
o Cluster infrastructure provided by Red Hat Cluster Suite
o Red Hat Cluster Suite lock architectures
o New volume manager, LVM2
o Enhanced gfs_fsck performance and changes to the gfs_fsck command
o Withdraw individual mount points
o Increased total storage supported
Cluster infrastructure provided by Red Hat Cluster Suite
This release of Red Hat GFS uses the cluster infrastructure of Red Hat
Cluster Suite, taking advantage of the Red Hat Cluster Suite configuration
file and cluster graphical user interface (GUI), system-config-cluster. For
information about configuring and managing Red Hat Cluster Suite, refer to
Red Hat Cluster Suite Configuring and Managing a Cluster. Previous versions
of Red Hat GFS provided a cluster infrastructure that was exclusive to GFS
(even though used with Red Hat Cluster Suite). Additionally, configuration
files in earlier versions of Red Hat GFS were created and maintained via
text editors only (that is, no GUI was available).
Red Hat Cluster Suite lock architectures
Via Red Hat Cluster Suite, GFS can use the following lock architectures:
o DLM (Distributed Lock Manager), new for Red Hat GFS 6.1 -- DLM provides
lock management throughout a Red Hat cluster, requiring no nodes to be
configured as lock management nodes (contrasted to GULM, which does
require certain nodes to be configured as lock management nodes).
o GULM (Grand Unified Lock Manager) -- A client/server lock architecture
that is compatible with Red Hat GFS 6.0.
o Nolock -- For single node operation only.
New volume manager, LVM2
The pool volume manager in earlier releases of Red Hat GFS is replaced with
LVM2 for this release. For information about converting pool volumes to the
LVM2 format and upgrading from GFS 6.0 to GFS 6.1, refer to "Appendix A
Upgrading GFS" of the Red Hat GFS 6.1 Administrator's Guide.
Enhanced gfs_fsck performance and changes to the gfs_fsck command
The gfs_fsck function performs 10 times as fast as gfs_fsck in earlier GFS
releases. (This enhancement has been included in a recent update to Red Hat
GFS 6.0, also.) In addition, the enhanced gfs_fsck function includes changes
to certain command options. The gfs_fsck command has changed in the
following ways:
o You can no longer set the interactive mode with Ctrl+C. Pressing
Ctrl+C now cancels the gfs_fsck command. Do *not* press Ctrl+C unless
you want to cancel the command.
o You can increase the level of verbosity by using the -v flag. Adding a
second -v flag increases the level again.
o You can decrease the level of verbosity by using the -q flag. Adding a
second -q flag decreases the level again.
o The -n option opens a file system as read-only and answers 'no' to any
queries automatically. It provides a way to try the command to reveal
errors without actually trying to change anything.
Refer to the Red Hat GFS 6.1 Administrator's Guide, "4.12. Repairing a File
System" and the gfs_fsck man page, gfs_fsck(8), for additional information.
Withdraw individual mount points
This release allows individual GFS mount points to gracefully discontinue
operations on a node without causing that node to panic. This feature
provides the ability to continue operations with unaffected file systems on
that node. The feature can be overridden to allow a node to panic, thereby
providing more information for troubleshooting. For more information, refer
to the mount command option, oopses_ok, in the Red Hat GFS 6.1
Administrator's Guide, "Table 4-2".
Increased storage supported
Red Hat GFS now supports 8 terabytes of storage per GFS file system.
For more information about Red Hat GFS requirements, refer to the
Red Hat GFS 6.1 Administrator's Guide, "Chapter 2. System Requirements".
Important Notes
For information about upgrading from GFS 6.0 to GFS 6.1, refer
to "Appendix A Upgrading GFS" of the Red Hat GFS 6.1 Administrator's Guide.
Multipath GNBD is not available with this releases of Red Hat GFS 6.1.
That is, device mapper multipath (dm-multipath) cannot use GNBD. GNBD without
multipath *is* available.
Related Documentation
The following related documentation is available at
http://www.redhat.com/docs/manuals/csgfs/:
o Red Hat GFS 6.1 Administrator's Guide
o Red Hat Cluster Suite Configuring and Managing a Cluster
o Release notes for Red Hat Cluster Suite 4