clvmd(8)
NAME
clvmd --- cluster LVM daemon
SYNOPSIS
clvmd [-C] [-d [value]] [-E lock_uuid] [-f] [-h] [-I cluster_manager] [-R] [-S] [-t timeout] [-T start_timeout] [-V]
DESCRIPTION
clvmd is the daemon that distributes LVM metadata updates around a cluster. It must be running on all nodes in the cluster and will give an error if a node in the cluster does not have this daemon running.
OPTIONS
-C
Only valid if -d is also specified. Tells all clvmds in a
cluster to enable/disable debug logging. Without this switch,
only the local clvmd will change its debug level to that given
with -d.
This does not work correctly if specified on the command-line
that starts clvmd. If you want to start clvmd and enable
cluster-wide logging then the command needs to be issued twice,
eg:
clvmd
clvmd -d2
-d [value]
Set debug logging level. If -d is specified without a value
then 1 is assumed. Value can be:
0 --- Disabled
1 --- Sends debug logs to stderr (implies -f)
2 --- Sends debug logs to syslog(3)
-E lock_uuid
Pass lock uuid to be reacquired exclusively when clvmd is
restarted.
-f
Don't fork, run in the foreground.
-h
Show help information.
-I cluster_manager
Selects the cluster manager to use for locking and internal
communications. As it is quite possible to have multiple
managers available on the same system you might have to manually
specify this option to override the search.
By default, omit -I is equivalent to -Iauto. Clvmd will use the
first cluster manager that succeeds, and it checks them in a
predefined order cman, corosync, openais. The available
managers will be listed by order as part of the clvmd -h output.
-R
Tells all the running instance of clvmd in the cluster to reload
their device cache and re-read the lvm configuration file
lvm.conf(5). This command should be run whenever the devices on
a cluster system are changed.
-S
Tells the running clvmd to exit and reexecute itself, for
example at the end of a package upgrade. The new instance is
instructed to reacquire any locks in the same state as they were
previously held. (Alternative methods of restarting the daemon
have the side effect of changing exclusive LV locks into shared
locks.)
-t timeout
Specifies the timeout for commands to run around the cluster.
This should not be so small that commands with many disk updates
to do will fail, so you may need to increase this on systems
with very large disk farms. The default is 60 seconds.
-T start_timeout
Specifies the start timeout for clvmd daemon startup. If the
daemon does not report that it has started up within this time
then the parent command will exit with status of 5. This does
NOT mean that clvmd has not started! What it means is that the
startup has been delayed for some reason; the most likely cause
of this is an inquorate cluster though it could be due to
locking latencies on a cluster with large numbers of logical
volumes. If you get the return code of 5 it is usually not
necessary to restart clvmd it will start as soon as that
blockage has cleared. This flag is to allow startup scripts to
exit in a timely fashion even if the cluster is stalled for some
reason.
The default is 0 (no timeout) and the value is in seconds. Don't
set this too small or you will experience spurious errors. 10 or
20 seconds might be sensible.
This timeout will be ignored if you start clvmd with the -d.
-V
Display the version of the cluster LVM daemon.
ENVIRONMENT VARIABLES
LVM_CLVMD_BINARY
The CLVMD binary to use when clvmd restart is requested.
Defaults to /usr/sbin/clvmd.
LVM_BINARY
The LVM2 binary to use. Defaults to /sbin/lvm.
FILES
/usr/sbin/clvmd /sbin/lvm
SEE ALSO
syslog(3), lvm.conf(5), lvm(8)
Opportunity
Personal Opportunity - Free software gives you access to billions of dollars of software at no cost. Use this software for your business, personal use or to develop a profitable skill. Access to source code provides access to a level of capabilities/information that companies protect though copyrights. Open source is a core component of the Internet and it is available to you. Leverage the billions of dollars in resources and capabilities to build a career, establish a business or change the world. The potential is endless for those who understand the opportunity.
Business Opportunity - Goldman Sachs, IBM and countless large corporations are leveraging open source to reduce costs, develop products and increase their bottom lines. Learn what these companies know about open source and how open source can give you the advantage.
Free Software
Free Software provides computer programs and capabilities at no cost but more importantly, it provides the freedom to run, edit, contribute to, and share the software. The importance of free software is a matter of access, not price. Software at no cost is a benefit but ownership rights to the software and source code is far more significant.
Free Office Software - The Libre Office suite provides top desktop productivity tools for free. This includes, a word processor, spreadsheet, presentation engine, drawing and flowcharting, database and math applications. Libre Office is available for Linux or Windows.
Free Books
The Free Books Library is a collection of thousands of the most popular public domain books in an online readable format. The collection includes great classical literature and more recent works where the U.S. copyright has expired. These books are yours to read and use without restrictions.
Source Code - Want to change a program or know how it works? Open Source provides the source code for its programs so that anyone can use, modify or learn how to write those programs themselves. Visit the GNU source code repositories to download the source.
Education
Study at Harvard, Stanford or MIT - Open edX provides free online courses from Harvard, MIT, Columbia, UC Berkeley and other top Universities. Hundreds of courses for almost all major subjects and course levels. Open edx also offers some paid courses and selected certifications.
Linux Manual Pages - A man or manual page is a form of software documentation found on Linux/Unix operating systems. Topics covered include computer programs (including library and system calls), formal standards and conventions, and even abstract concepts.
