VSAN – Page 31

Exploring VSAN APIs Part 9 – VSAN Component count

04.09.2014 by William Lam // 4 Comments

The last topic that I would like to explore before concluding my VSAN API blog series are some of the advanced VSAN disk statistics that are available for either troubleshooting or informational purposes. One such statistic that would be handy to know about is the number of VSAN Components per ESXi host, which I have already demonstrated in my recent VSAN configuration maximum query script and VSAN PowerCLI vCheck Plugins.

These disk statistics are made available through the VSAN InternalSystem manager and using the QueryPhysicalVsanDisks() vSphere API method, we can either retrieve all or a specific set of properties for each ESXi host. I have created a sample vSphere SDK for Perl script called vsanDiskStatsQueries.pl that will demonstrate the use of this API.

Disclaimer: These scripts are provided for informational and educational purposes only. It should be thoroughly tested before attempting to use in a production environment.

Here is an example of running the script against a VSAN Cluster which will produce the number of VSAN components for each ESXi host:

./vsanDiskStatsQueries.pl --server vcenter55-1.primp-industries.com --username root --cluster VSAN-Cluster

If we take a look at the script, you will notice we filtered on two specific properties: lsom_objects_count and owner. One thing to note is the output for this method is JSON string, so you will need to parse the output accordingly.

The owner property indicates the UUID of a specific ESXi host and the lsom_objects_count represents the number of VSAN components. To be able to identify the particular ESXi host and compare it to the owner property, we use the QueryHostStatus() API which was discussed in Exploring VSAN APIs Part 5. Once we have a match for the current ESXi host, we simply extract the lsom_objects_count property which I use a simple hash table to keep track of the results and display it at the very end of the script.

This concludes my 9-part series of exploring the new VSAN APIs. Hopefully for those of you who followed the series have enjoyed it, I know I definitely had fun learning about the new APIs and how you can automate every aspect of VSAN from a scripting and programmatic perspective.

VSAN vCheck Plugins

04.07.2014 by William Lam // 5 Comments

After creating my VSAN Configuration Maximum query script I thought it would also be useful to create an equivalent set of VSAN vCheck Plugins. For those of you who have not heard of or used vCheck (pretty rare unless you do not use PowerShell/PowerCLI in your environment), it is a PowerShell reporting HTML framework created by Alan Renouf. vCheck allows you to schedule a series of PowerCLI scripts/checks against your vSphere environment and produces a daily report on the things you care most about such as datastore capacity being under a certain threshold or potential snapshots growing out of control in your environment.

Given this is the primary use case for vCheck, I figure it would make sense to implement these same set of VSAN configuration maximum checks in vCheck as well. This would also give me the opportunity to learn more about vCheck as I have never used it before. If you are new to vCheck, I highly recommend you check out Jonathan Medd's article on how to get started with vCheck here.

Here is a sample report of a real VSAN environment to get an idea of what the report could look like: VSAN-vCheck-Report.html

Below are the VSAN vCheck Plugins that I have created which also includes a bonus plugin which reports on the capacity of a VSAN Datastore. You can pick and choose the VSAN plugins that you want to use in your environment and then customize the threshold parameter for each report based on your requirements.

For those of you who are looking to evaluate VSAN in their environment, hopefully these VSAN vCheck reports will come in handy. If there are others that you feel that might be useful, feel free to leave a comment or contribute back to the vCheck project on Github.

Exploring VSAN APIs Part 8 – Maintenance Mode

04.02.2014 by William Lam // Leave a Comment

When it is time to patch, upgrade or service an ESXi host running VSAN, the first thing you will want to do is to place the host into Maintenance Mode. If you have never performed this operation on a VSAN host before, you should be aware that there is a new option to specify how the data for VSAN will be migrated. Below is a screenshot of the three options provided when using the vSphere Web Client.

To learn more about the new VSAN data migration option, I highly recommend you check out Cormac Hogan's blog article here which goes into more detail. From a vSphere API point of view, the Maintenance Mode operation is still being provided by the traditional EnterMaintenanceMode_Task() method, but there is now a new optional property called HostMaintenanceSpec that specifies the option (exposed as an enum) to use for VSAN data migration. To demonstrate this functionality, I have created a sample vSphere SDK for Perl script called vsanHostMaintenanceMode.pl

Disclaimer: These scripts are provided for informational and educational purposes only. It should be thoroughly tested before attempting to use in a production environment.

The script requires three input parameters:

vihost - Name of the ESXi host to perform the maintance mode operaton
operation - The operation to perform [enter|exit]
mode - The VSAN data migration policy [ensure|evac|no]

Here is an example of placing an ESXi host into Maintenance Mode using the "Ensure Accessibility" VSAN data migration option:

./vsanHostMaintenanceMode.pl --server vcenter55-1.primp-industries.com --username root --vihost vesxi55-1.primp-industries.com --operation enter --mode ensure

To take the ESXi host out of Maintance Mode, you can run the following command:

./vsanHostMaintenanceMode.pl --vcenter55-1.primp-industries.com --username root --vihost vesxi55-1.primp-industries.com --operation exit