Michael Schroeder - ElasticSky

17. November 202215. March 2024

Manage ESXi Coredump Files

Okay, admit it, this is not a new topic, but it cost me some time in a client project. Since this blog also acts as a swap partition of my brain, I wrote it down for future reference. It is important to follow the steps correctly so that the changes are preserved after a reboot.

Why a Coredump-File?

Modern ESXi installations starting with version 7 use a new partition layout of the boot device. Coredumps are also located there. But only when the boot medium is not a USB flash medium and not an SD card. In such cases the coredump is relocated to a VMFS datastore with at least 32GB capacity.

This is exactly the case I found in a customer environment. The system was migrated from vSphere 6.7 and therefore still had the old boot layout on a ( at that time still fully supported) SD-Card RAID1. We found a vmkdump folder with files for each host on one of the shared VMFS datastores. This (VMFS5) datastore was supposed to be decommissioned and replaced with a VMFS6 datastore. (Side note from the VCI: there is no online migration path from VMFS5 to VMFS6) 😉 So the vmkdump files had to be removed from there.

Procedure

First, we get an inventory of the coredump files.

esxcli system coredump file list

All coredump files of all ESXi hosts are listed here. Each line contains the path and the Active and Configured (true or false) states. Active means that this is the current coredump file of this host. It is important that the value for Configured also has the status ‘true’. Otherwise the setting will not survive a reboot. Only the coredump file of the current host has the status ‘active’. All other files belong to other hosts and are therefore active=false.

By default, the host chooses the first matching VMFS datastore. This is not necessarily the desired one.

Remove the current Coredump-File

First we delete the active coredump file of the host. We have to force the removal because it is set as active=true.

esxcli system coredump file remove --force

If we execute the list command from above again, there should be one line less.

Add a new Coredump File

The next command creates a new coredump file at the destination. If it does not already exist, a vmkdump folder is created and the dumpfile is created in it. We specify the desired file name without extension, because it will be created automatically (.dumpfile).

esxcli system coredump file add -d <Name | UUID> -f <filename>

Example: Name of the host is “ESX-01” and the VMFS datastore has the name “Service”. The datastore may be specified as either DisplayName or Datastore_UUID.

esxcli system coredump file add -d Service -f ESX-01

A folder vmkdump will be created on the designated datastore and a file named ESX-01.dumpfile will be created in it. We can check this using the list command.

esxcli system coredump file list

A new line will appear with the full path to the new dumpfile. However, the status is still active=false and configured=false. It might be useful to copy this full path to the clipboard, because it is required in the next step.

Activate Dumpfile

In the following step, we set the created dumpfile to active. This way, the setting is retained even after a host reboot. We specify the complete path to the dumpfile. The copy from the clipboard is helpful here and avoids typos.

esxcli system coredump file set -p <path_to_dumpfile>

Example:

esxcli system coredump file set -p /vmfs/volumes/<UUID>/vmkdump/ESX-01.dumpfile

A final List command validates the result.

VMware Explore EMEA – Review and Outlook

VMware Explore 2022 has come to a close. Four days packed with information, conversations and activities. Now it’s time to pause and take a recap of the last few days. I won’t go into technical innovations, products or announcements here. I will write separate technical articles for that and there is also the VMware Explore Video Library with numerous videos including a recording of the General Session and many of the Breakout Sessions. Instead, I would like to go into things that I liked very much and also those that have potential for improvement. Not all points concern VMware itself – in many cases they are things that were good or not so good at the sidelines. Perhaps it will inspire some readers to consider a visit to VMware Explore in the future.

A Plus – VMware Explore 2022 on site in Barcelona

The fact that after two cancelled VMworlds (yes, World) an on-site event took place again is a big plus. No matter who I asked in the last few days – everyone was tired of the virtual meetings and was looking forward to the personal contact. From this perspective, VMware-Explore 2022 was bound to be a success.

A Plus – Public Transport

The Fira is located just outside the city center. So for those who have accommodation in the center, there are twice daily trips by public transport. Barcelona’s metro system is well organized and the trains run at a tight schedule. I rarely had to wait more than 5 minutes for a connecting train. The tickets are cheap and VMware gave out cards of 10-rides at registration. But you have to ask for them. Even if you buy a 10-rides ticket for the Barcelona city area yourself, it currently costs less than €8. This has even become a little cheaper compared to 2019.

The transfer to and from the airport is also cheap and reliable. A special airport bus runs at short intervals between the terminal and the city center (Placa Espana and Placa Catalunya). Pro tip: Buy a return ticket straight away, it’s cheaper.

Attention. After midnight, many lines close down. So night owls should have some cash ready for a cab, or plan a long walk to the hotel.

Blogger Program with Potential for Improvement

There were only 15 blogger passes in total, which is very few if seen in terms of the entire EMEA region. This also hit some of my fellow bloggers who had been providing excellent VMworld contributions for many years in a row and now surprisingly missed out.

At this point I would like to thank Elisabeth Kefal, who included me in the official program in the follow-up.

To clarify, this is not a full travel package. All bloggers always finance flight and accommodation on their own. Only the admission pass to the VMware Explore is sponsored by VMware. So costs can only have played a minor role.

After all, it’s the bloggers who have a deep reach into the community in their respective countries and beyond. I don’t like the word “influencer,” but it does come pretty close to the role of tech bloggers. Let’s call them “community networkers.” They are mostly the same people who are active in the VMware User Group (VMUG) and maintain close contact with the user base there.

The current practice should be reconsidered here. Instead, it would be nice to prioritize inviting bloggers in the future who are not only seasonally active during the 4 days of VMware-Explore, but who keep the community together all year round and constantly deliver valuable content.

9. November 202211. November 2022

VMware-Explore EMEA is back

It was almost exactly three years ago that IT experts from all over the world met in Barcelona for the VMware IT trade fair, which was then still called VMworld. Due to the pandemic, the following events in 2020 and 2021 had to be canceled and held virtually instead. Certainly an alternative in times of emergency, but no substitute for the on-site event. Lectures and presentations are only a small aspect. Much more important, on the other hand, is personal contact and networking.

VMworld is now VMware Explore

This year’s event is a new beginning in many aspects. The rebranding may be subject to controversy. VMworld was a constant term within the community and many are still having a hard time with the new brand. That VMware-Explore is a new beginning can also be seen in the visitor numbers. While there were more than 12,000 visitors in Barcelona in 2019, the organizers expected only about half that figure in 2022. Also from the experience from the North America event in San Francisco which remained far below expectations. Surprisingly, demand in the EMEA region is high and instead of around 6,000 estimated attendees, there are over 7,500, not including VMware employees.

12. October 202212. October 2022

VMware vSphere 8 is GA !

Waiting is over. Fire up your download engines and get VMware vSphere8 binaries.

The wait has been rewarded. After the announcement at VMware Explore 2022 in North America, the installer files are now available on the VMware Portal (login required).

Author: Michael Schroeder