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Changing the default size of the ESX-OSData volume in ESXi 7.0

05.02.2020 by William Lam // 29 Comments

In ESXi 7.0, a new partition scheme was introduced which also brings along a new set of storage requirements. These changes are explained in the official documentation here and the following VMware KB 77009 also contains some additional info which can be helpful. Storage changes are not easy but this was necessary to not only better support some of the current capabilities but more importantly, it setups the foundation for future ESXi capabilities.

The biggest change to the partition layout is the consolidation of VMware Tools Locker, Core Dump and Scratch partitions into a new ESX-OSData volume (based on VMFS-L). This new volume can vary in size (up to 138GB) depending on a number of factors including the current ESXi boot media (USB SD-Card, Local Disk) but also the size of the device itself, which is explained in the official documentation.

From some of the comments on Twitter, Reddit and the direct inquiries that I have received, this new behavior seems to be most impactful to smaller homelabs where a fresh install of ESXi 7.0 has been performed. Folks have shared that their ESX-OSData volume has taken up 120GB which can be quite significant if you have a smaller disk which can be quite common. I normally install ESXi on a USB device and I also use vSAN, which has a different behavior and I have also not upgraded my physical ESXi host (E200-8D) to 7.0 yet.

I performed a fresh installation of ESXi 7.0 (running as Nested ESXi VM) that was configured with 1TB of storage and here is what the filesystem layout now looks:


We can see that the ESX-OSData volume takes up ~119.75GB, which is not too bad for 1TB volume but I can understand this may not be ideal if you have something smaller such as 250GB to 512GB disk. Due to the size of the local device, the boot options mentioned in the KB would not be helpful and I was curious myself if this ESX-OSData volume size could be configurable. In doing some research it looks like the size of the ESX-OSData can be specified using the following ESXi boot option (SHIFT+O during the initial boot) called autoPartitionOSDataSize

UPDATE (12/17/20) - Official support for specifying the size of ESX-OSData has been added to the release of ESXi 7.0 Update 1c with a new ESXi kernel boot option called systemMediaSize which takes one of four values:

  • min = 25GB
  • small = 55GB
  • default = 138GB (default behavior)
  • max = Consumes all available space

If you do not require or have 138GB for the ESX-OSData, you can override the default behavior by appending this option with the specified value (e.g. systemMediaSize=min). It is worth noting that by using this setting, the smallest ESX-OSData volume you can configure is 25GB. For homelabs or environment which require less than this, you would have to use the unsupported autoPartitionOSDataSize parameter , which is not officially supported as mentioned below.

Disclaimer: This may not be officially supported by VMware as it deviates from the system defaults and can have other unintended behaviors. Use at your own risk.

[Read more...]

Categories // ESXi, Home Lab, vSphere 7.0 Tags // ESX-OSData, ESXi 7.0, vSphere 7.0

Important - NVMe SSD not found after upgrading to ESXi 7.0

04.16.2020 by William Lam // 17 Comments

Several folks in the community had reported issues that after upgrading from ESXi 6.7 to 7.0, their Samsung NVMe PCIe SSDs were no longer showing up. The first report of this was from Ivo Beerens and eventually found that reinstalling ESXi from scratch works but certainly that was not ideal. Just yesterday, I saw that Jeffrey Kusters also shared a similiar issue and used a different workaround which allowed him to upgrade. I also reached out to VMware Engineering as they thought this was a strange behavior but needed to see the logs to understand what was actually going on. Since Jeffrey's setup was an upgrade, I was able to get a copy of his vm-support bundle to provide to Engineering.

Within minutes of looking at the support bundle, they quickly identified the issue and this was caused by using the incorrect ESXCLI command to upgrade a standalone ESXi host from 6.7 to 7.0. Instead of using "esxcli software vib update" command, folks should be using "esxcli software profile update" which has always been the correct command to use when upgrading an ESXi image. In fact, this has been in the vSphere documentation for quite some time and here is the ESXi 7.0 version of that documentation. More importantly, the incorrect command only upgrades the ESXi 6.7 VIBs that exists and does not install any of the ESXi 7.0 VIBs, which means after the upgrade, you are not only missing the nvme-pcie VIB but many other ESXi 7.0 VIBs!

tl;dr - If you are going to use ESXCLI to upgrade your standalone ESXi host, please make sure to use the correct command or you will have issues. Below are the two commands you will need to determine which ESXi Image Profiles are available given an offline bundle and then updating to a specific image profile.

List Image Profiles from ESXi 7.0 Offline Bundle:

[root@e200-8d:~] esxcli software sources profile list -d /vmfs/volumes/e200-8d-local-datastore/VMware-ESXi-7.0.0-15843807-depot.zip
Name Vendor Acceptance Level Creation Time Modification Time
---------------------------- ------------ ---------------- ------------------- -------------------
ESXi-7.0.0-15843807-standard VMware, Inc. PartnerSupported 2020-03-16T10:48:54 2020-03-16T10:48:54
ESXi-7.0.0-15843807-no-tools VMware, Inc. PartnerSupported 2020-03-16T10:48:54 2020-03-16T10:48:54

Upgrade to a specific Image Profile from ESXi 7.0 Offline Bundle:

esxcli software profile update -d /vmfs/volumes/e200-8d-local-datastore/VMware-ESXi-7.0.0-15843807-depot.zip -p ESXi-7.0.0-15843807-standard

Categories // ESXi, vSphere 7.0 Tags // esxcli, ESXi 7.0

Quick Tip - Allow unsupported CPUs when upgrading to ESXi 7.0

04.16.2020 by William Lam // 69 Comments

As outlined in the vSphere 7.0 release notes (which everyone should carefully read through before upgrading), the following CPU processors are no longer supported:

  • Intel Family 6, Model = 2C (Westmere-EP)
  • Intel Family 6, Model = 2F (Westmere-EX)

To help put things into perspective, these processors were released about 10 years ago! So this should not come as a surprise that VMware has decided remove support for these processors which probably also implies the underlying hardware platforms are probably quite dated as well. In any case, this certainly has affected some folks and from what I have seen, it has mostly been personal homelab or smaller vSphere environments.

One of my readers had reached out to me the other day to share an interesting tidbit which might help some folks prolong their aging hardware for another vSphere release. I have not personally tested this trick and I do not recommend it as you can have other issues longer term or hit a similiar or worse situation upon the next patch or upgrade.

Disclaimer: This is not officially supported by VMware and you run the risk of having more issues in the future.

Per the reader, it looks like you can append the following ESXi boot option which will allow you to bypass the unsupported CPU during the installation/upgrade. To do so, just use SHIFT+O (see VMware documentation for more details) and append the following:

allowLegacyCPU=true

There have also been other interesting and crazy workarounds that attempt to workaround this problem. Although some of these tricks may work, folks should really think long term on what other issues can face by deferring hardware upgrade. I have always looked at homelab as not only a way to learn but to grow yourself as an individual.

Note: The boot option above is only temporarily and you will need to pass in this option upon each restart. It looks like this setting is also not configurable via ESXCLI which I initially had thought, so if you are installing this on a USB device, the best option is to edit the boot.cfg and simply append the parameter to kernelopt line so it'll automatically be included for you without having to manually typing this. If this is install on disk, then you will need to edit both /bootbank/boot.cfg and /altbootbank/boot.cfg for the settings to passed in automatically.

This is ultimately an investment you are making into yourself, so do not cut yourself short and consider looking at a newer platform, especially something like an Intel NUC which is fairly affordable both in cost as well as power, cooling and form factor.

Categories // ESXi, Home Lab, Not Supported, vSphere 7.0 Tags // allowLegacyCPU, ESXi 7.0

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William is Distinguished Platform Engineering Architect in the VMware Cloud Foundation (VCF) Division at Broadcom. His primary focus is helping customers and partners build, run and operate a modern Private Cloud using the VMware Cloud Foundation (VCF) platform.

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