Yellow Bricks

by Duncan Epping

esxcli

Enabling Memory Tiering in VCF/vSphere 9.1 through the CLI!

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I saw a question internally this week about enabling Memory Tiering through the CLI with 9.1 and why that didn’t work as you would expect. I wrote an article about the esxcli commands a while back, so I went through them and then I realized indeed that the article was outdated. I participated in a few early access programs and one of the things we had to do was enable memory tiering using the new esxcli namespace. Where in the past there were  various advanced settings you had to configure, and various commands to run, they now made things much easier. Just some examples below.

The new name space:

esxcli memtier

Enable memory tiering using a particular device:

esxcli memtier enable -d <device_name>

Enable memory tiering using a particular device and with a 400% ratio percentage, this value can be between 1 and 400:

esxcli memtier enable -d <device_name> -r 400%

Enable encryption after memory tiering has been configured:

esxcli memtier config set --encryption true

You can find the full documentation here and here.

How do I set an advanced setting which is not listed through esxcli on the commandline?

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Someone asked this question recently, and it is a valid point, it seems that some namespaces are not available through esxcli when it comes to the advanced settings. Now you can of course set the advanced settings via the UI, but in some cases you may need/want to script them. This is possible when you use one of the older CLIs available on your host, namely “vim-cmd”. Now, vim-cmd was never really intended to be used by administrators so I would urge caution. However, in some cases it is very difficult to get around it, and for instance, setting “Config.HostAgent.ssl.keyStore.allowSelfSigned” to “true” is one of those. You can’t, to my knowledge, currently do this via esxcli. You can, however, simply do this via vim-cmd. The syntax is as follows:

vim-cmd hostsvc/advopt/update name.option type value

In my particular case, that means the command would look like this:

vim-cmd hostsvc/advopt/update Config.HostAgent.ssl.keyStore.allowSelfSigned bool "true"

Where “update” is used to update the value for the advanced setting. If you just want to list all settings first you could use the following command:

vim-cmd hostsvc/advopt/settings

I hope that helps someone out there!

Enabling maintenance mode via esxcli

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I have been having to place my lab host into maintenance mode a few times now via the command-line, for whatever reason I just keep forgetting the command that I should use to place my host into maintenance mode using esxcli, so I figured I would dump it here so I can find it easily. Hopefully, now it sticks…

enter maintenance mode:

esxcli system maintenanceMode set --enable true

exit maintenance mode:

esxcli system maintenanceMode set --enable false

vSphere Flash Read Cache and esxcli

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As most features these days in vSphere you can configure them using the awesome esxcli command. I’ve already mentioned esxcli in my vSphere Flash Read Cache FAQ blog but I wanted to call it out explicitly here as I found it very useful. You can get some nice details using the esxcli command. So where do we start?

First thing would be:

esxcli storage vflash

This will return that there are 3 namespaces: cache, module and device. Lets start top down with device. The command “esxcli storage vflash device list” will show you a list of all flash devices and whether it has been configured for vFRC or not. The module namespace can provide you some more details around for instance cache blocksizes etc. If you run the command this is what the output looks like:

~ # esxcli storage vflash module get
 Min Supported Module Version: 1.0.0.0
 Revision: 1.0.0.0
 Supported Cache Block Size Max: 1048576
 Supported Cache Block Size Min: 4096
 Supported Cache Size Max: 214748364800
 Supported Cache Size Min: 4194304
 Supported Disk Size Max: 17592186044416
 Supported Mode Mask: WriteThru

[Read more…] about vSphere Flash Read Cache and esxcli

Pinging from different VMkernel NICs using esxcli?

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Today I had a network issue in my lab, I still don’t have a clue what the issue was but I did discover something useful. I had 3 different VMkernel’s setup and I wanted to make sure each of the three had network connection to a specific destination address. After going through the esxcli command I bumped in to the following command which I found very helpful:

esxcli network diag ping -I vmk0 -H 10.27.51.132

In this case I use VMkernel Interface “vmk0” to ping to the address “10.27.51.132”. If I want to use a different VMkernel Interface I just specify it, so swap “vmk0” with “vmk1” for instance. Useful right?!