Using ESXCLI V2 to Configure Storage Multipathing

A customer recently came to me with the need to use ESXCLI to configure a bunch of storage settings on all of their ESXi hosts.  He had been planning on connecting to the local console of each host and then executing the command, but wanted to know if there was a better way.  Of course there is!  We could use plink to run a script on his workstation that would establish SSH connections to his servers and then execute the ESXCLI commands... or we can do it all through PowerCLI!

I actually tackled this same problem 5 years ago using get-esxcli.  At that point, I did it with the normal V1 version of the cmdlet, which required carefully spaced lists of parameters, leading to ugly lines like this: $esxcli.storage.core.device.set($thisLUN.CanonicalName,$null,$null,$queueFullSample,$queueFullThreshold,$null)

No more!  Now, we have access to get-esxcli -v2, which is much easier to use!  Instead of needing to put a bunch of $nulls into the .set() method to space out our values, we can use the .createArgs() method to create an object with named parameters!  Then, we set appropriate values for each of those parameters and feed that object into an .invoke() method to set them!  It sounds a bit complex, but it's pretty easy to understand once you see it in practice.

So, I put together this quick script to set the storage values that this customer needed.  I built this script to target all of the hosts in his environment that were in maintenance mode, so that he could execute this script as he needed it.  I included an additional -vmhost parameter so that he could use a regex to further limit the scope of the script, as well.

The script is pretty straight forward.  It gets the list of target ESXi hosts, then goes through each one invoking the necessary changes via esxcli.  The first thing that it does (after getting the ESXCLI for the host) is invoke the .createargs() method to create an object that contains all of the applicable arguments for that bit of ESXCLI.  That's an extremely handy tool, because you can then look at the object that it generates to get an idea about what settings can be managed.  Also, you don't have to mess around with getting them in the right order or counting out the nulls as place-holders!

So, the script takes that object and puts appropriate values in each of its parameters.  After that, it invokes that object to set those values and is good to go!  Pretty easy, right?

As always, this script is published as-is with no guarantees.  Although it worked for me in my situation, that doesn't mean that it'll work for you in yours.  Test everything you find online thoroughly and make sure that you fully understand what it's going to do before executing it in your environment!

Comments

Post a Comment

Sorry guys, I've been getting a lot of spam recently, so I've had to turn on comment moderation. I'll do my best to moderate them swiftly after they're submitted,

Popular posts from this blog

Clone a Standard vSwitch from one ESXi Host to Another

One of my customers is standardizing the configurations on their HP C7000 enclosures (they've been set up at various sites by various administrators with varying involvement from the architecture team).  As such, we need to stand up some temporary resources so that we can take down the main enclosure for reconfiguration.  That's fine, we can easily ship a smaller enclosure to each site for temporary compute resources.  Some of the sites are using Standard vSwitches, so we need to be able to quickly copy the networking configuration over from their existing blades to these new, slightly different blades.  As I see it, we had 2 good options: 1) Capture a Host Profile with the desired vSwitch configuration.  Delete every other component of the Host Profile so that only the networking section is applied; design the new ESXi hosts so that the vSwitches'll work with the old vmnic-to-vswitch configurations. 2) Write a script to clone the vSwitch from ones ESXi host...
Read more

PowerShell Sorting by Multiple Columns

PowerShell's Sort-Object cmdlet is super useful, especially when preparing output for human consumption.  A few people have found my blog while looking for more information about its use, specifically while looking for how to sort by multiple columns (well, properties, technically).  I've never done so (much less written about it), so I hope those folks found answers elsewhere.  But, it got me curious... and it turns out that it's really easy. The Technet article on Sort-Object has the answer directly spelled out: just use commas to create a list of properties to sort by (in order to precedence).  Let's look at some examples!  First, prepare a variable with some good sortable data: $myData = get-eventlog System -newest 25 And then we can get to sorting!  Say you want to sort primarily by EntryType (Warning, Information, Error) and then by Source.  Easy-peasy: $myData | sort EntryType,Source How about if you want it to be in descending or...
Read more

Deleting Orphaned (AKA Zombie) VMDK Files

A problem that most Virtualization Administrators need to deal with is Orphaned VMDK files (or Zombie VMDK files, as some people call them).  These are Virtual Machine hard drive files that are just hanging out, taking up storage, but are attached to no VMs.  How can this happen?  Well, the most common way is when an administrator needs to delete a VMDK but isn't quite ready to commit... so, after pressing "remove", they select "remove from virtual machine" rather than "remove and delete files".  The intent is always good: "I want to be able to restore this if it turns out to be necessary... so I'll just come back and delete it next week if nothing breaks!"  But, of course, next week something else happens and the file doesn't get deleted.  After a little while, it turns into "which files did I rename, again?" and nothing seems to happen. So, how do you deal with these orphaned files?  Well, a few years ago I found a scrip...
Read more