Pdsh - Revision history

Leo at 16:51, 23 March 2023

2023-03-23T16:51:33Z

← Older revision		Revision as of 16:51, 23 March 2023
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	== Cheat sheet ==		== Cheat sheet ==
			Depending on your pdsh install, it may default to rsh rather than ssh. Pass in <code>-R ssh</code> to change the default module.
	{\| class="wikitable"		{\| class="wikitable"
	!Action		!Action
	!Command		!Command
			\|-
			\|List all installed modules
			\|<code>pdsh -L</code>
			\|-
			\|Use a specific module. Eg. SSH
			\|<code>pdsh -R ssh -w node[0-10] uptime</code>
			\|-
			\|Connect to a certain nodes with a specific module
			\|<code>pdsh -w ssh:node[0-5],rsh:node[6-7] uptime</code>
	\|-		\|-
	\|Run a command on all hosts		\|Run a command on all hosts
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	=== Modules ===		=== Modules ===
	Run <code>pdsh -L</code> to list all remote command modules available.		Run <code>pdsh -L</code> to list all remote command modules available.

			You can see the default module that will be used when running <code>pdsh --help</code>.

	==== SSH remote module ====		==== SSH remote module ====

Leo at 22:57, 23 January 2023

2023-01-23T22:57:01Z

← Older revision		Revision as of 22:57, 23 January 2023
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	Run <code>pdsh -L</code> to list all remote command modules available.		Run <code>pdsh -L</code> to list all remote command modules available.

	For SSH support, you will need to install the <code>pdsh-rcmd-ssh</code> package.		==== SSH remote module ====
			For SSH support, you will need to install the <code>pdsh-rcmd-ssh</code> package. Additional SSH arguments can be passed by passing in the PDSH_SSH_ARGS_APPEND environment variable. Eg:
			{{Highlight
			\| code = # PDSH_SSH_ARGS_APPEND=”-o StrictHostKeyChecking=no -o UserKnownHostsFile=/dev/null -o LogLevel=error” pdsh -a uptime
			\| lang = terminal
			}}

	== Configuration ==		== Configuration ==

Leo at 22:55, 23 January 2023

2023-01-23T22:55:16Z

← Older revision		Revision as of 22:55, 23 January 2023
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	\|Run a command on all hosts		\|Run a command on all hosts
	\|<code>pdsh -a uptime</code>		\|<code>pdsh -a uptime</code>
			\|-
			\|Run a command on all hosts EXCEPT one
			\|<code>pdsh -a -x exclude-node uptime</code>
	\|-		\|-
	\|Run a command on a set of hosts by hostname		\|Run a command on a set of hosts by hostname
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	\|<code><nowiki>pdsh -a cat /etc/redhat-release \| dshbak -c</nowiki></code>		\|<code><nowiki>pdsh -a cat /etc/redhat-release \| dshbak -c</nowiki></code>
	\|}		\|}

			== Installation ==
			You can install pdsh from the epel repo.
			{{Highlight
			\| code = # yum -y install epel-release
			# yum -y install pdsh pdsh-rcmd-ssh
			\| lang = terminal
			}}
			Alternatively, install from source from the GitHub repo at: https://github.com/chaos/pdsh

			=== Modules ===
			Run <code>pdsh -L</code> to list all remote command modules available.

			For SSH support, you will need to install the <code>pdsh-rcmd-ssh</code> package.

	== Configuration ==		== Configuration ==

	=== Genders file ===		=== Genders file ===
	The genders file can be used to give attributes to nodes in a cluster. It can be thought of as groups that can be used as a target when running pdsh commands.		The genders file can be used to give attributes to nodes in a cluster. It can be thought of as groups that can be used as a target when running pdsh commands. While the genders file isn't required, it's still a good idea to have set up because it allows the <code>-a</code> option to function properly.

	The genders file is usually located at <code>/etc/genders</code>. Each line can contain one or more hosts and attributes are given as a comma delimited list. Here is an example genders file:		The genders file is usually located at <code>/etc/genders</code>. Each line can contain one or more hosts and attributes are given as a comma delimited list. Here is an example genders file:
Line 36:		Line 53:
	* Only cluster A nodes with <code>pdsh -w cluster-a</code>		* Only cluster A nodes with <code>pdsh -w cluster-a</code>
	* Only nodes with 8 CPUs with <code>pdsh -w cpus=8</code>		* Only nodes with 8 CPUs with <code>pdsh -w cpus=8</code>

			== See also ==

			* Libgenders man page talks about using genders and target grouping - https://linux.die.net/man/3/libgenders

Leo: Created page with "The pdsh command is a parallel version of the dsh (Distributed Shell). It is used to run commands on multiple remote hosts in parallel and supports a number of remote shell programs including SSH. == Cheat sheet == {| class="wikitable" !Action !Command |- |Run a command on all hosts |`pdsh -a uptime` |- |Run a command on a set of hosts by hostname Or by a specific gender (ie. attribute), see below. |`pdsh -w node[0-10] uptimepdsh -w cpus=8 u..."`


2023-01-23T22:23:34Z
Created page with "The pdsh command is a parallel version of the dsh (Distributed Shell). It is used to run commands on multiple remote hosts in parallel and supports a number of remote shell programs including SSH.  == Cheat sheet == {| class="wikitable" !Action !Command |- |Run a command on all hosts |<code>pdsh -a uptime</code> |- |Run a command on a set of hosts by hostname Or by a specific gender (ie. attribute), see below. |<code>pdsh -w node[0-10] uptime</code><code>pdsh -w cpus=8 u..."
New page
The pdsh command is a parallel version of the dsh (Distributed Shell). It is used to run commands on multiple remote hosts in parallel and supports a number of remote shell programs including SSH.



== Cheat sheet ==

{| class="wikitable"

!Action

!Command

|-

|Run a command on all hosts

|<code>pdsh -a uptime</code>

|-

|Run a command on a set of hosts by hostname

Or by a specific gender (ie. attribute), see below.

|<code>pdsh -w node[0-10] uptime</code><code>pdsh -w cpus=8 uptime</code>

|-

|Collect the OS version on all hosts and group it

|<code><nowiki>pdsh -a cat /etc/redhat-release | dshbak -c</nowiki></code>

|}



== Configuration ==



=== Genders file ===

The genders file can be used to give attributes to nodes in a cluster. It can be thought of as groups that can be used as a target when running pdsh commands.



The genders file is usually located at <code>/etc/genders</code>. Each line can contain one or more hosts and attributes are given as a comma delimited list. Here is an example genders file:

{{Highlight

| code = ca-controller management

ca-login cluster-a,login

ca[001-168] cluster-a,cpus=4

cb-login cluster-b,login

cb[091-320] cluster-b,cpus=8

| lang = terminal

}}

Using this example, you can target:



* Only the control node with <code>pdsh -w management</code>

* Only cluster A nodes with <code>pdsh -w cluster-a</code>

* Only nodes with 8 CPUs with <code>pdsh -w cpus=8</code>