Man page or keyword search:   man All Sections 1 - General Commands 2 - System Calls 3 - Subroutines, Functions 4 - Special Files 5 - File Formats 6 - Games and Screensavers 7 - Macros and Conventions 8 - Maintenence Commands 9 - Kernel Interface New Commands Server 4.4BSD AIX Alpinelinux Archlinux Aros BSDOS BSDi Bifrost CentOS Cygwin Darwin Debian DigitalUNIX DragonFly ElementaryOS Fedora FreeBSD Gentoo GhostBSD HP-UX Haiku Hurd IRIX Inferno JazzOS Kali Knoppix LinuxMint MacOSX Mageia Mandriva Manjaro Minix MirBSD NeXTSTEP NetBSD OPENSTEP OSF1 OpenBSD OpenDarwin OpenIndiana OpenMandriva OpenServer OpenSuSE OpenVMS Oracle PC-BSD Peanut Pidora Plan9 QNX Raspbian RedHat Scientific Slackware SmartOS Solaris SuSE SunOS Syllable Tru64 UNIXv7 Ubuntu Ultrix UnixWare Xenix YellowDog aLinux   33470 pages apropos Keyword Search (all sections) Output format html ascii pdf view pdf save postscript

o2cb(7)			      OCFS2 Manual Pages		       o2cb(7)

NAME
       o2cb - Default cluster stack for the OCFS2 file system.

DESCRIPTION
       o2cb  is	 the  default  cluster	stack  for  the	 OCFS2 file system. It
       includes a node manager (o2nm) to keep track of the nodes in the	 clus‐
       ter,  a	heartbeat  agent  (o2hb) to detect live nodes, a network agent
       (o2net) for intra-cluster node communication  and  a  distributed  lock
       manager	(o2dlm)	 to keep track of lock resources. All these components
       are in-kernel. It also includes an in-memory  file  system,  dlmfs,  to
       allow userspace to access the in-kernel dlm.

       This    cluster	  stack	  has	two   configuration   files,   namely,
       /etc/ocfs2/cluster.conf and  /etc/sysconfig/o2cb.  Whereas  the	former
       keeps  track of the cluster layout, the latter keeps track of the clus‐
       ter timeouts. Both files are only read  when  the  cluster  is  brought
       online.	Values	in  use	 by  the  online cluster can be perused in the
       /sys/kernel/config/cluster directory structure.

CONFIGURATION
       The cluster layout is specified in /etc/ocfs2/cluster.conf. While it is
       easier	to  populate  and  propagate  this  configuration  file	 using
       ocfs2console(8), one can also do it by manually	as  long  as  care  is
       taken to format the file correctly.

       While  the console utility is intuitive to use, there are few points to
       keep in mind.

	    1. The node name needs to match the hostname. It does not need  to
       include	the  domain  name.  For	 example,  appserver.oracle.com can be
       appserver.

	    2. The IP address need not be the one associated with  that	 host‐
       name.  As  in, any valid IP address on that node can be used. O2CB will
       not attempt to match the node name (hostname)  with  the	 specified  IP
       address.

       For  best performance, use of a private interconnect (lower latency) is
       recommended.

       The cluster.conf file is in a stanza format with two types of  stanzas,
       namely,	cluster and node. A typical cluster.conf will have one cluster
       stanza and multiple node stanzas.

       The cluster stanza has two parameters:

       node_count
	      Total number of nodes in the cluster

       name   Name of the cluster

       The node stanza has five parameters:

       ip_port
	      IP port

       ip_address
	      IP address

       number Unique node number from 0-254

       name   Hostname

       cluster
	      Name of the cluster

       Users  populating  cluster.conf	manually  should  follow  the	format
       strictly. As in, stanza header should start at the first column and end
       with a colon, stanza parameters should start after a tab, a blank  line
       should demarcate each stanza and care taken to avoid stray whitespaces.

       The  O2CB cluster timeouts are specified in /etc/sysconfig/o2cb and can
       be configured using the o2cb init script.

       These timeouts are used by the O2CB clusterstack to determine whether a
       node  is dead or alive. While the use of default values is recommended,
       users can experiment with other values if the defaults are causing spu‐
       rious fencing.

       The cluster timeouts are:

       Heartbeat Dead Threshold
	      The  Disk	 Heartbeat  timeout is the number of two second itera‐
	      tions before a node is considered dead. The exact	 formula  used
	      to convert the timeout in seconds to the number of iterations is
	      as follows:

	      O2CB_HEARTBEAT_THRESHOLD = (((timeout in seconds) / 2) + 1)

	      For e.g., to specify a 60 sec timeout, set it  to	 31.  For  120
	      secs,  set  it  to  61.  The default for this timeout is 60 secs
	      (O2CB_HEARTBEAT_THRESHOLD = 31).

       Network Idle Timeout
	      The Network Idle timeout	specifies  the	time  in  milliseconds
	      before  a	 network connection is considered dead. It defaults to
	      30000 ms.

       Network Keepalive Delay
	      The Network Keepalive specifies the maximum delay	 in  millisec‐
	      onds  before a keepalive packet is sent to another node to check
	      whether it is alive or not.  If  the  node  is  alive,  it  will
	      respond. Its defaults to 2000 ms.

       Network Reconnect Delay
	      The  Network  Reconnect specifies the minimum delay in millisec‐
	      onds between connection attempts. It defaults to 2000 ms.

EXAMPLES
       A sample /etc/ocfs2/cluster.conf.

       cluster:
	   node_count = 3
	   name = webcluster

       node:
	   ip_port = 7777
	   ip_address = 192.168.0.107
	   number = 7
	   name = node7
	   cluster = webcluster

       node:
	   ip_port = 7777
	   ip_address = 192.168.0.106
	   number = 6
	   name = node6
	   cluster = webcluster

       node:
	   ip_port = 7777
	   ip_address = 192.168.0.110
	   number = 10
	   name = node10
	   cluster = webcluster

SEE ALSO
       mkfs.ocfs2(8) fsck.ocfs2(8) tunefs.ocfs2(8) debugfs.ocfs2(8)  ocfs2con‐
       sole(8)

AUTHORS
       Oracle Corporation

COPYRIGHT
       Copyright © 2004, 2010 Oracle. All rights reserved.

Version 1.8.0			September 2010			       o2cb(7)

Vote for polarhome