vCenter Server – Page 12

Dynamic memory resizing for vCenter Server 6.0

02.23.2015 by William Lam // 32 Comments

In previous releases of vSphere, scaling up resources such as storage or memory for vCenter Server was a huge pain-point for our customers. Before the various vCenter Server services can consume the new resources, some additional manual steps were required. Though this type of an operation is usually infrequent, there is still an operational overhead which can potentially lead to increased downtime of your vCenter Server.

For example, increasing storage capacity for the VCSA was an offline operation that required adding an additional disk and then copying the existing content to the new disk which can be quite error prone and lead to a significant amount of downtime. In vSphere 6.0, the VCSA now uses LVM which provides the ability for online storage capacity increase without any downtime to vCenter Server. Increasing memory was also challenging because you had to manually adjust several configuration files that manages the JVM heap settings for various vCenter Server services as described in this VMware KB. Having complex workflows to perform basic resource expansion can increase risk of errors, especially when the process is foreign to those performing it for the very first time.

To help solve this problem, in vSphere 6.0 vCenter Server (Windows & VCSA) now includes a built-in dynamic memory reconfiguration process that automatically runs at boot up. This process includes a dynamic algorithm that inspects the current amount of CPU, Memory and Storage that is available to determine the appropriate size to configure the vCenter Server. This means that if you no longer have to tweak individual JVM settings for the various services within vCenter Server, this will happen automatically by analyzing the resources that are available and then calculating the configuration based on the supported maximums for vCenter Server.

Note: In vSphere 6.0, there are additional services going beyond just the core vCenter Server, vSphere Web Client, vCenter SSO and Inventory Services.

The dynamic memory algorithm is configured to understand the minimal amount of resources for running a vCenter Server and is bounded between a "Tiny" configuration which is 2vCPU and 8GB memory and a "Large" configuration which is 16vCPU and 32GB memory. This is important to note because if you try to configure the vCenter Server with less memory than the minimal supported, though the algorithim will dynamically distribute the available memory to the various resources, it could lead to performance degradation as the different services may not be receiving the amount of memory they require to run. YMMV if you decide to reduce the supported amount of memory but the algorithm will distribute what's available.

The process which does all the magic is a utility called cloudvm-ram-size and there are several useful options to be aware of. To view the current memory assignment for the various vCenter Server services including the OS, you can run the following command on the VCSA as an example:

cloudvm-ram-size -l

From the screenshot above, we can see a very simple break down of the current memory assignment for a "Tiny" deployment which has 8GB of memory.

To show that the dynamic memory algorithm is in fact running when more memory is added, the example below is of a VCSA that was initially configured with 8GB of memory. I then capture the running configuration and then shut down the vCenter Server and increased its memory to 10GB. I then power on the VCSA and capture the running state and you can see differences in the screenshot below.

Another useful command to be aware is being able to see the current memory usage for all services. You can do this by running the following command:

cloudvm-ram-size -S

As you can see the dynamic memory algorithm is a very much welcome feature for vCenter Server and will greatly simplify the operational tasks when needing to scale up or down resources such as CPU and Memory. I know this is definitely one of the enhancements I have been waiting for and I am glad to see it here in the new vSphere 6.0 release! As of right now, a system reboot is required but who knows maybe in the future we can increase memory while the VCSA is still running and simply reloading the services ...

Quick Tip - Start & Stop order for vCenter Server Services

12.04.2014 by William Lam // 9 Comments

A couple weeks back I had worked on something that required me to shutdown all the vCenter Server Services on a VCSA (vCenter Server Appliance). There is no high level service that can be stopped which would properly shutdown all the different services in the appropriate order. Luckily, one can easily derive the start and stop order by just taking a look at the runlevel scripts (S* for start and K* for Kill scripts). I have extracted the order in which the vCenter Server Services must be stopped and started which is shown below:

Stop Order:

vmcad
vmdird
vmkdcd
vmware-inventoryservice
vmware-logbrowser
vmware-netdumper
vmware-vpxd
vsphere-client
vmware-stsd
vmware-sts-idmd

Start Order:

vmcad
vmdird
vmkdcd
vmware-netdumper
vmware-sts-idmd
vmware-stsd
vmware-inventoryservice
vmware-logbrowser
vmware-vpxd
vsphere-client

Note: Although I mention the VCSA, the ordering also applies to a vCenter Server for Windows which has the exact same services.

Here is a simple shell script snippet that can be used to stop all vCenter Server Services in the appropriate order:

VMWARE_SERVICE_STOP=(
vmcad
vmdird
vmkdcd
vmware-inventoryservice
vmware-logbrowser
vmware-netdumper
vmware-vpxd
vsphere-client
vmware-stsd
vmware-sts-idmd
)

for i in ${VMWARE_SERVICE_STOP[@]};
do
  /etc/init.d/$i stop
done

}

Here is a simple shell script snippet that can be used to start all vCenter Server Services in the appropriate order:

VMWARE_SERVICE_START=(
vmcad
vmdird
vmkdcd
vmware-netdumper
vmware-sts-idmd
vmware-stsd
vmware-inventoryservice
vmware-logbrowser
vmware-vpxd
vsphere-client
)

for i in ${VMWARE_SERVICE_START[@]};
do
  /etc/init.d/$i start
done

Automating VCSA 5.5 Configurations including SSO Administrator password

11.03.2014 by William Lam // 3 Comments

As many of you know, I am a huge fan of the VCSA (vCenter Server Appliance), not only for its ease of deployment and setup but also the fact that I can easily automate the entire deployment in just under a couple of minutes. I have written about this topic in the past using the vpxd_servicecfg command to automate both VCSA 5.0 and VCSA 5.1. I figured it was probably a good idea to update this for latest VCSA 5.5 which includes several new enhancements to vpxd_servicecfg command such as the VMware Customer Experience Improve Program configuration (vTelemtry) among other options that you can explore by simply running the vpxd_servicecfg on the VCSA.

The other reason I wanted to update this for the latest VCSA 5.5 is that I was working with Engineering last week on a project and several of them did not know about this capability of being able to automate the VCSA configuration. Instead of providing them with the raw commands, I thought I would create an updated script that can be shared with the community so that others could also benefit from it. Lastly, I also did this for myself as I deploy a large amount of VCSA for all sorts of testing that I am doing on a regular basis and this would allow me to quickly speed up my deployment by simply going to my own blog 🙂

Below is a shell script that contains several variables that can be edited based on your environment setup and you can run this script over SSH using something like: ssh root@[VCSA-IP] < configureVCSA.sh

#!/bin/bash
# William Lam
# www.virtuallyghetto.com
# Script to automate VCSA 5.5+ Configurations

# User Configurations

# SSO Administrator password (*protected email*)
SSO_ADMINISTRATOR_PASSWORD=VMware1!

# Join Active Directory (following 5 variables required)
JOIN_AD=0
AD_DOMAIN=primp-industries.com
AD_USER=administrator
AD_PASS=mysupersecurepassword
VCENTER_HOSTNAME=vcenter51-1.primp-industries.com

# Enable NTP
ENABLE_NTP=0
NTP_SERVERS=192.168.1.1

# Enable VMware Customer Experience Improvement Program
ENABLE_VC_TELEMTRY=1

################ DO NOT EDIT BEYOND HERE ################
 
echo "Accepting VMware EULA ..."
/usr/sbin/vpxd_servicecfg eula accept

if [ ${JOIN_AD} -eq 1 ]; then
        echo "Configuring vCenter Server hostname ..."
        SHORTHOSTNAME=$(echo ${VCENTER_HOSTNAME} |  cut -d. -f1)
        /bin/hostname ${VCENTER_HOSTNAME}
        echo ${VCENTER_HOSTNAME} > /etc/HOSTNAME
        sed -i "s/localhost/${SHORTHOSTNAME}/g" /etc/hosts
 
        echo "Configuring Active Directory ..."
        /usr/sbin/vpxd_servicecfg ad write "${AD_USER}" "${AD_PASS}" ${AD_DOMAIN}
fi

echo "Enbaling Time Synchronization ..."
if [ ${ENABLE_NTP} -eq 1 ]; then
	/usr/sbin/vpxd_servicecfg timesync write ntp ${NTP_SERVERS} 
else
	/usr/sbin/vpxd_servicecfg timesync write tools 
fi 

echo "Configuring vCenter Server Embedded DB ..."
/usr/sbin/vpxd_servicecfg db write embedded
								 
echo "Configuring vCenter Server SSO w/custom *protected email* password ..."
/usr/sbin/vpxd_servicecfg sso write embedded ${SSO_ADMINISTRATOR_PASSWORD}

echo "Starting the vCenter Server Service ..."
/usr/sbin/vpxd_servicecfg service start

if [[ -e /var/log/vmware/phonehome ]] && [[ ${ENABLE_VC_TELEMTRY} -eq 1 ]]; then
	echo "Enabling vCenter Server Telemtry ..."
	/usr/sbin/vpxd_servicecfg telemetry enable
fi