vSphere 5 - 4 - Eric Sloof

Monday, January 23. 2012

What happens to resource pools when vCenter goes down?

A fellow VCI who was teaching the vSphere 5 What's New training course got a question from a student asking what happens to resource pools when vCenter goes down, because with vSphere 5.0 all the setting for resource pools are "moved" to vCenter.

Andy Cary who works as a Senior Technical Trainer at VMware responded immediately with: I created a RP on my vCenter and turned off expandable reservations for memory. Placed VM1 under said resource pool and failed to power up because the VM need to reserve memory for the overhead of running the VM (had no reservations set on the RP). So next I directly connected to the host and powered on the VM with no problem at all. However when you go back to the vCenter it displays:

The Cluster with the RP is now invalid because it can see the VM has powered on. So the configuration about DRS RP is saved on the vCenter but it doesn’t stop you going directly to the host an powering on the VM. Now in vSphere 5.0 if you directly connect to a host and try and create a local resource pool it will throw up an error saying this isn’t allowed because it can see you are managed by vCenter, this is the case even if the Host isn’t a member of DRS cluster. So the creation and management of RP is done via vCenter, if vCenter goes down the rules cannot be applied so you could get admin powering on VMs by directly connecting to the hosts. So in summary all we have done is said “You can only create, modify resource pools via vCenter and not by directly connecting to the host”

Saturday, January 21. 2012

White Paper - Mobility and Disaster Recovery Solution for Virtualized Tier-1 Enterprise Applications

To meet ever growing IT infrastructure needs and to ensure business continuity in case of a site-level disaster, it is critical to have live mobility and fully automated, efficient disaster recovery (DR) processes for virtualized enterprise applications across data centers. Failure to have a robust and efficient mobility and fully automated disaster recovery solution can result in millions of dollars of lost revenue and employee productivity.

This white paper showcases a flexible solution from Cisco®, VMware®, and EMC® that allows customers to efficiently achieve live mobility and fully automated DR for virtualized enterprise applications across data centers with less than 10ms round-trip time (RTT) latency between them.

Live mobility for virtualized applications across data centers enables IT organizations to efficiently meet various operational needs, e.g., data capacity expansion, seamless migrations, disaster avoidance, etc.

Fully automated DR allows customers to protect their mission critical enterprise applications against site-level disasters and ensures business continuance. A key advantage of this solution over manual, runbook style DR process execution is "minimum downtime with lowest Recovery Time Objective (RTO)". This is extremely critical for next generation cloud solutions required to host hundreds to thousands of virtualized applications on the same shared infrastructure.

The Cisco, VMware, and EMC design presented in this white paper is very modular so that, based on customer requirements, there is flexibility to deploy both the live mobility and fully automated DR solution or deploy any one of these solutions.

http://www.cisco.com/en/US/docs/solutions/Enterprise/Data_Center/DCI/4.0/EMC/mobdisasterrecapps.html

Friday, January 20. 2012

Video - Install vSphere Syslog Collector and configure ESXi logging

Logging in vSphere 5.0 has been significantly enhanced. You now have fine-grained control over system logs, the location where logs are sent, and, for each log, default size and rotation policy. You can set up logging with the vSphere Client or with the esxcli system syslog command and the PowerCLI VMHostSysLogServer Commandlets. You can also set up logging behaviour for a host by using the Host Profiles interface in the vSphere Client and can then import that host profile into other hosts. VMware vSphere ESXi 5.0 hosts run a syslog service (vmsyslogd) which provides a standard mechanism for logging messages from the VMkernel and other system components. By default in ESXi, these logs are placed on a local scratch volume or a ram disk. To preserve the logs further, ESXi can be configured to place these logs to an alternate storage location on disk, and to send the logs across the network to a syslog server. You have to install the vSphere Syslog Collector to enable ESXi system logs to be directed to a server on the network, rather than to a local disk. It’s possible install the Syslog Collector on the same machine as the associated vCenter Server, or on a different machine that has network connection to the vCenter Server. The Syslog Collector service binds to an IPv4 address for communication with vCenter Server, and does not support IPv6. The vCenter Server can be on a host machine in an IPv4-only, IPv4/IPv6 mixed-mode, or IPv6-only network environment, but the machine that connects to the vCenter Server through the vSphere Client must have an IPv4 address for the Syslog Collector service to work. In the ESXi Software panel there's an Advanced Setting called Syslog.global.LogHost, the value of this setting presents the remote host to which syslog messages are forwarded and port on which the remote host receives syslog messages. You can include the protocol and the port, for example, ssl://hostName1:514. UDP (default), TCP, and SSL are supported. The remote host must have syslog installed and correctly configured to receive the forwarded syslog messages. Checkout the video how the syslog service is installed on the vCenter host. You can also set up ESXi Syslog from the Host Profiles Interface. Hosts provisioned with Auto Deploy usually do not have sufficient local storage to save system logs. You can specify a remote syslog server for those hosts by setting up a reference host, saving the host profile, and applying that host profile to other hosts as needed. Best practice is to set up the syslog server on the reference host with the vSphere Client or the esxcli system syslog command and save the host profile. In some situations, setting up syslog from the Host Profiles interface is an alternative.

Thursday, January 12. 2012

Forbes Guthrie has released the vSphere 5 vReference Card

The card is available under a Creative Commons license, so feel free to copy and distribute this in paper or electronic format. Just check back frequently to www.vReference.com for updates, or subscribe to the RSS feed to be the first to know.

Forbes Guthrie: At long last, the vSphere 5.0 vReference Card is ready. Go and grab it over here. This time I’ve split it up into both an A4 version and a separate Letter size one. This should hopefully make the printing experience more consistent regardless of which side of the pond you try.New with this release is a full page version. This is the same information as the card, but I’ve increased the font to a less eye-ball screamingly small font. This should make it make much more conducive to reading as a study guide, or if you want to bone-up on a particular area.

Tuesday, January 3. 2012

VMware KB: Upgrading to vCenter Server 5.0 best practices

VMware supports in-place upgrades on 64-bit systems from vCenter Server 4.x to vCenter Server 5.0. You can upgrade VirtualCenter 2.5 Update 6 or later and vCenter Server 4.0.x to vCenter Server 5.0 by installing vCenter Server 5.0 on a new machine and migrating the existing database.

This upgrade method makes it possible to upgrade from a 32-bit system to a 64-bit system. Alternatively, if the VirtualCenter or vCenter Server database is on a remote machine, you can upgrade the database. vCenter Server 5.0 can manage ESX 3.5.x/ESXi 3.5.x hosts in the same cluster with ESX 4.x/ESXi 4.x hosts.

You cannot upgrade a vCenter Server 4.x instance that is running on Windows XP Professional x64 Edition to vCenter Server 5.0, because vCenter Server 5.0 does not support Windows XP Professional x64. This article provides information about upgrading to vCenter Server 5.0.

VMware KB: Upgrading to vCenter Server 5.0 best practices

Sunday, December 11. 2011

Myth - VMware HA datastore heartbeats prevent host isolation

What are datastore heartbeats?

The host-X-hb (where X is the host’s MOID) is Located on each heartbeat datastore, this file is used to check for slave liveness through the heartbeat datastore. This file is checked by the master host if the master loses network heartbeats from the slave.

For VMFS datastores, the vSphere HA agent locks this file with an exclusive lock and relies on the VMkernel heartbeat to indicate liveness. For NFS datastores, vSphere HA periodically updates the time stamp to this file to indicate liveness.

The host-X-poweron (where X is the host’s MOID) is a per-host file that contains the list of all virtual machines that are powered on. This file is used as a communication channel if a management network outage occurs. Isolated slaves use this file to tell the master that it is isolated as well as to tell the master which virtual machines it has powered off.

The master host must determine whether the slave host:

• Actually crashed
• Is not responding because of a network failure
• The HA agent is in an unreachable state

The absence of both a network and datastore heartbeat indicates full host failure. Datastores are used as a backup communication channel to detect virtual machine and host heartbeats. Datastore heartbeats are used to make the distinction between a failed, an isolated or a partitioned host.

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