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Retrieving Information from a Distributed vSwitch

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There was a question on the VMTN community forums about retrieving the security policies: promiscuous, forged transmits and MAC Address change from a distributed vSwitch and distributed portgroup and I realized my getdvSwitchInfo.pl script that I wrote awhile back only included basic information about the dvSwitch.

I spent some time updating my vSphere SDK for Perl script to include additional information such as the high level summary, configuration of the dvSwitch, network resource pools, dvportgroups, hosts attached to dvSwitch and virtual machines attached to the dvSwitch. The script also includes information about many of the new features in vSphere 5.0 networking such as netflow, port mirror, LLDP, NIOC to just name a few. You can take a look at the What's New in vSphere 5 Networking whitepaper for more details.

The script allows for the following type of "list" operations: summary, config, networkpool, portgroup, host and vm. In addition, you can display all information by specifying the "all" operation and you can specify a specific dvSwitch by using the --dvswitch flag and providing the name of a dvSwitch.

Here is an example output for the list "summary" operation for all dvSwitches:

Here is an example output for the list "config" operation on a specific dvSwitch:

Here is an example output for the list "networkpool" operation on a specific dvSwitch:

Here is an example output for the list "portgroup" operation on a specific dvSwitch:

Here is an example output for the list "host" operation on a specific dvSwitch:

Here is an example output for the list "vm" operation on a specific dvSwitch:

Hopefully this script will be helpful if you need to quickly get information about your dvSwitches.

Identifying Idle vCenter Sessions

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I recently received a question on how to identify idle vCenter sessions that may stem from a non-active vSphere Client or vSphere API connection. Properly managing sessions to your vCenter Server is as important as knowing who is logging in. If you exhaust the maximum number of connections, you can easily deny login access to other users and/or services that are needed to connect to vCenter Server which can lead to very bad things. In the worse case, you can even prevent administrators from logging into a new session to help terminate any stale/idle connections.

The vSphere API provides a sessionManagement manager to help you manage all sessions, including checking whether a session is still active and terminating a session. I wrote a quick vSphere SDK for Perl script called sessionManagement.pl which allows you to list all sessions for a given vCenter and terminating a a specific session. Every session has a unique sessionKey that the vCenter Server uses to track and it provides information such username, login time and last active which can be used to create an unattended script to automatically terminate sessions that have gone beyond a certain threshold.

Here is an example script output of performing the "list" operation:

Note: There maybe vCenter Plugins/Extensions that creates sessions such as CapacityIQ, those will be denoted by "vCenter Ext Session" field. These should not be terminated as it can negatively impact 3rd party applications.

Here is an example script output of terminating a specific session using the "disconnect" operation which you will need to specify sessionkey provided in the previous command:

For those of you that are interested in creating your own script to terminate idle sessions, you can use the DateTime Perl module to help with calculating the amount of idle time and comparing that to a pre-defined timeout value.

vSphere MoRef (Managed Object Reference) ID Finder Script

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There was an interesting article this morning by my colleague Dave Hill about Looking up Managed Object Reference (MoRef) in vCenter Server, which references a VMware KB article showing you how to use vSphere MOB to find MoRef IDs.

A Managed Object Reference ID also known just as MoRef ID is a unique value that is generated by the vCenter Server and is guaranteed to be unique for a given entity in a single vCenter instance. Steve Jin has a great article going into detail about MoRef's, that you should check out here. MoRef ID's are not only used in vSphere, but they can also be referenced in other VMware products such as vCD (vCloud Director) or SRM to name a few or even by 3rd party/custom tools as a way to uniquely track objects within vCenter.

Using the vSphere MOB is one way of retrieving the MoRef ID, but of course this can be tedious if you are trying to locate MoRef's for multiple entities, in multiple vCenters. I decided to write a quick vSphere SDK for Perl script called moRefFinder.pl that allows a users to quickly query for a variety of Managed Objects (VM,Host,Cluster,Datacenter,Resource Pool,Network, Distributed vSwitch, Folder, vApp and Datastore) in a vCenter Server.

I also noted earlier, MoRef ID is only unique within a vCenter instance, so how do you track these objects across multiple vCenters? Well, VMware introduced a new property called instanceUUID (128 bit UUID) which is unique for a given vCenter Server and you can use this along with the MoRef ID to uniquely track objects across multiple vCenters and the script automatically outputs this value for any query.

Note: There have been some optimization in the latest vSphere SDK for Perl 5.0, it is recommended you use the latest version which is backwards compatible with vSphere 3.x and 4.x

The script requires two parameters:

  • type - The type of managed object
  • name - The name of the object as seen in vCenter Server

Here is an example querying for a Virtual Machine:

Here is an example querying for a Host:

Here is an example querying for a Cluster:

Here is an example querying for a Datacenter:

Here is an example querying for a Resource Pool:

Here is an example querying for a Network (Portgroup):

Here is an example querying for a Distributed vSwitch:

Here is an example querying for a Folder:

Here is an example querying for a vApp:

Here is an example querying for a Datastore: