Password Expiration

# chage --list test

# chage -M 60 test : This makes the password to expire after 60 Days.

# chage -W 5 test : Warning days before password expire.

Linux Swapiness

The swappiness parameter controls the tendency of the kernel to move processes out of physical memory and onto the swap disk. Because disks are much slower than RAM, this can lead to slower response times for system and applications if processes are too aggressively moved out of memory.

swappiness can have a value of between 0 and 100

swappiness=0 tells the kernel to avoid swapping processes out of physical memory for as long as possible.

swappiness=100 tells the kernel to aggressively swap processes out of physical memory and move them to swap cache.

How to Lock / UnLock (Enable / Disable) Linux User Account

To lock, you can use the follow command:

# passwd -l username (where username is the login id).

To Unlock the same account:

# passwd -u username 

VCS Command For Reference Part II

Service Group Operations
hagrp -list – List all service groups
hagrp -resources [service_group] – List a service group’s resources
hagrp -dep [service_group] – List a service group’s dependencies
hagrp -display [service_group] – Get detailed information about a service group
hagrp -online groupname -sys systemname – Start a service group and bring it resources
hagrp -offline groupname -sys systemname – Stop a service group and take it resources offline
hagrp -switch groupname -to systemname – Switch a service group from one system to another
hagrp -freeze -sys -persistent – Gets into Maintenance Mode. Freeze a service group. This will disable online and offline operations
hagrp -unfreeze -sys -persistent] – Take the servicegroup out of maintenance mode
hagrp -enable service_group [-sys system] – Enable a service group
hagrp -disable service_group [-sys system] – Disable a service group
hagrp -enableresources service_group – Enable all the resources in a service group
hagrp -disableresources service_group – Disable all the resources in a service group
hagrp -link parent_group child_group relationship – Specify the dependency relationship between two service groups
hagrp -unlink parent_group child_group – Remove the dependency between two service groups

VCS Commands For Reference

LT status
lltconfig -a list – List all the MAC addresses in cluster
lltstat -l – Lists information about each configured LLT link
lltstat [-nvv|-n] – Verify status of links in cluster

Starting and stopping LLT
lltconfig -c – Start the LLT service
lltconfig -U – stop the LLT running

GAB status
gabconfig -a – List Membership, Verify id GAB is operating
gabdiskhb -l – Check the disk heartbeat status
gabdiskx -l – lists all the exclusive GAB disks and their membership information

Starting and stopping GAB
gabconfig -c -n seed_number – Start the GAB
gabconfig -U – Stop the GAB

Cluster Status
hastatus -summary – Outputs the status of cluster
hasys -display – Displays the cluster operation status

Start or Stop services
hastart [-force|-stale] – ‘force’ is used to load local configuration
hasys -force 'system' – start the cluster using config file from the mentioned “system”
hastop -local [-force|-evacuate] – ‘local’ option will stop the service only on the system you type the command
hastop -sys 'system' [-force|-evacuate] – ‘sys’ stops had on the system you specify
hastop -all [-force] – ‘all’ stops had on all systems in the cluster

Change VCS Configuration online
haconf -makerw – makes VCS configuration in read/write mode
haconf -dump -makero – Dumps the configuration changes

Agent Operations
haagent -start agent_name -sys system – Starts an agent
haagent -stop agent_name -sys system – Stops an agent

Cluster Operations
haclus -display – Displays cluster information and status
haclus -enable LinkMonitoring – Enables heartbeat link monitoring in the GUI
haclus -disable LinkMonitoring – Disables heartbeat link monitoring in the GUI

Add and Delete Users
hauser -add user_name – Adds a user with read/write access
hauser -add VCSGuest – Adds a user with read-only access
hauser -modify user_name – Modifies a users password
hauser -delete user_name – Deletes a user
hauser -display [user_name] – Displays all users if username is not specified

System Operations
hasys -list – List systems in the cluster
hasys -display – Get detailed information about each system
hasys -add system – Add a system to cluster
hasys -delete system – Delete a system from cluster

Resource Types
hatype -list – List resource types
hatype -display [type_name] – Get detailed information about a resource type
hatype -resources type_name – List all resources of a particular type
hatype -add resource_type – Add a resource type
hatype -modify .... – Set the value of static attributes
hatype -delete resource_type – Delete a resource type

Resource Operations
hares -list – List all resources
hares -dep [resource] – List a resource’s dependencies
hares -display [resource] – Get detailed information about a resource
hares -add resource_type service_group – Add a resource
hares -modify resource attribute_name value – Modify the attributes of the new resource
hares -delete resource – Delete a resource type
hares -online resource -sys systemname – Online a resource, type
hares -offline resource -sys systemname – Offline a resource, type
hares -probe resource -sys system – Cause a resource’s agent to immediately monitor the resource on a particular system
hares -clear resource [-sys system] – Clear a faulted resource
hares -local resource attribute_name value – Make a resource’s attribute value local
hares -global resource attribute_name value – Make a resource’s attribute value global
hares -link parent_res child_res – Specify a dependency between two resources
hares -unlink parent_res child_res – Remove the dependency relationship between two resources