New features of Win Server 2022 Failover Clustering

Failover Cluster feature being one of the top ones on Windows Servers. So Microsoft keeps adding new enchancements. Lets discuss on these.

Cluster Affinity with Azure Stack HCI

Affinity is a rule you would set up that establishes a relationship between two or more roles (i,e, virtual machines, resource groups, and so on) to keep them together. AntiAffinity is the same but is used to try to keep the specified roles apart from each other. AntiAffinity was only available upto 2019. So basically this provides “Streched Cluster” capabilities. Hopefully across different geo locations. read more https://docs.microsoft.com/en-us/azure-stack/hci/manage/vm-affinity

AutoSites

AutoSites is another feature brought over from Azure Stack HCI. AutoSites is basically what is says. When you configure Failover Clustering, it will first look into Active Directory to see if Sites are configured. If they are and the nodes are included in a site, we will automatically create site fault domains and put the nodes in the fault domain they are a member of.

Granular Repair

When a node goes down for maintenance, crashes, or whatever the case may be, once it comes back up, there is a “repair” job run where data is moved around and onto the drives, if necessary, of the node that came back. A repair is basically a resync of the data between all the nodes. Depending on the amount of time the node was down, the longer it could take for the repair to complete. read more https://docs.microsoft.com/en-us/azure-stack/hci/manage/storage-repair-speed

Cluster Shared Volumes and Bitlocker

Cluster Shared Volumes (CSV) enable multiple nodes in a Windows Server Failover Cluster or Azure Stack HCI to simultaneously have read-write access to the same LUN (disk) that is provisioned as an NTFS volume. BitLocker Drive Encryption is a data protection feature that integrates with the operating system and addresses the threats of data theft or exposure from lost, stolen, or inappropriately decommissioned computers.

BitLocker on volumes within a cluster are managed based on how the cluster service “views” the volume to be protected. BitLocker will unlock protected volumes without user intervention.

SMB Encryption

Windows Server 2022 SMB Direct now supports encryption. Previously, enabling SMB encryption disabled direct data placement, making RDMA performance as slow as TCP. Now data is encrypted before placement, leading to relatively minor performance degradation while adding AES-128 and AES-256 protected packet privacy. Furthermore, Windows Server Failover Clusters now support granular control of encrypting intra-node storage communications for Cluster Shared Volumes (CSV) and the storage bus layer (SBL). This means that when using Storage Spaces Direct and SMB Direct, you can decide to encrypt the east-west communications within the cluster itself for higher security.

[source: Microsoft]

Creating Host groups and adding Hosts to Nagios

Today we are going to discuss on Nagios Host group creation and Host addition for the Nagios platform. The host groups provide clean grouping of the hosts. 

Creating Host Groups in Nagios

  • Create a hostgroups.cfg using the below command

vi /usr/local/nagios/etc/objects/hostgroups.cfg

  • Then add the following to the hostgroups.cfg.

define hostgroup {
         hostgroup_name NAMEOFGROUP
         alias NAMEOFGROUP alias
}

  • Add the entry in the Nagios.cfg file

nano /usr/local/nagios/etc/nagios.cfg

  • Then, add the below line at the end of the file

cfg_file=/usr/local/nagios/etc/objects/hostgroups.cfg

  • Finally, we need to add the servers to the host group (as below)

define host {
host_name NAMEOFHOST
alias NAMEOFHOST
address xxx.xxx.xxx.xxx
hostgroups NAMEOFGROUP
}

  • Also, make sure to restart the nagios service – service nagios restart

Then, we will look at Host addition process

Continue reading “Creating Host groups and adding Hosts to Nagios”

On Agents (Ubuntu)

  • Install the NRPE tools – sudo apt-get install nagios-nrpe-server nagios-plugins
  • After that, need to define the Nagios server address

sudo nano /etc/nagios/nrpe.cfg

  • Then access the “allowed_hosts” section and update as appropiately [i.e: allowed_hosts=127.0.0.1, xxx.xxx.xxx.xxx]
  • Save and exit the changes, then restart the NRPE service

sudo systemctl restart nagios-nrpe-server

  • You may verify the NRPE service with the command – /usr/lib/nagios/plugins/check_load -w 15,10,5 -c 30,25,20

On Nagios Server

  • Once you are done with the Agents, you come back to the Nagios server. Even here, we start by installing the NRPE – sudo apt install nagios-nrpe-plugin
  • Then, access the relavent config file and enable “servers” category 

sudo nano /usr/local/nagios/etc/nagios.cfg

  • To enable cfg_dir=/usr/local/nagios/etc/servers simply uncomment the line
  • After that, we need to create custom commands for Monitoring sensors

sudo nano /usr/local/nagios/etc/objects/commands.cfg

  • In the bottom of cfg file, you may add the following (save and close to commit the changes)

define command {
command_name check_nrpe
command_line $USER1$/check_nrpe -H $HOSTADDRESS$ -c $ARG1$
}

  • Next, we need to create a client coniguration file – sudo nano /usr/local/nagios/etc/servers/client.cfg
  • There, you may define the host systems with the required object definitions

NOTE: make sure to verify whether the used syntaxes are correct with the below command. Also please refer the Nagios official documentation

sudo /usr/local/nagios/bin/nagios -v /usr/local/nagios/etc/nagios.cfg

  • Finally, restart the nagios [sudo systemctl restart nagios] service and hopefully you should be seeing the Hosts