ESXi 8.x Install error - TSCs are out of sync: cpu1 > cpu27

[MichaelSJames]

Hi Community,

I hope I have placed this request for help in the correct location. I did not see another that was obvious.

I have been trying to install ESXi 8.x on 2 separate Dell Precision T7910 servers without success. They are similarly configured with 128GB Ram and Dual Intel Xeon E5-2697 v3 CPU's.

There is a problem with the ESXi installation in that on both servers I receive a similar error message "TSCs are out of sync: cpu1 > cpu27".

I've spent some time checking the server configurations and moving things around. The only thing I have noticed is when I manipulate the RAM configuration the cpu numbers in the error message change.

The CPU's are identical in both servers. One server has a pair of Intel Xeon E5-2697 v3 CPU's. The other server has a pair of Intel Xeon E5-2690 v3 CPU's.

Is there a workaround for this error or can the installer be customised to bypass this issue.

Please see the attached screenshots showing error message and CPU configuration.

Many thanks in advance.

Michael J

[scott28tt]

There is an area of the Communities dedicated to ESXi, I have reported this post to the moderators asking them to move it there, so it gets the best audience.

[MichaelSJames]

Thanks Scott - much appreciated.

[pmichelli]

Are you using the Dell customized ISO for ESXi 8.0 that has all the drivers it needs?

[bluefirestorm]

The Dell Precision 7910 is a workstation (not a server) so you won't find it in the VMware HCL for systems and a customised Dell ESXi ISO is unlikely to resolve this TSC issue.

The E5-26xx v3 series of CPUs is also not officially supported under ESXi 8.x either.
https://www.vmware.com/resources/compatibility/detail.php?deviceCategory=cpu&productid=84&deviceCate...

You could try the suggested workaround using the boot option timerForceTSC=TRUE as specified in this KB https://kb.vmware.com/s/article/65186

The E5-26xx v4 (Broadwell) series is supported under ESXi 8.x according to the VMware HCL but it is better to jump this TSC hurdle first before deciding if upgrading to E5-26xx v4 would be worthwhile in your use-case. The E5-26xx v3 and v4 are socket compatible and the Precision 7910 A34 BIOS supports both v3 and v4 CPUs.

[MiguelSanchez1]

Implemented workaround using Ctrl-O and added timerForceTSC=TRUE. Same result on Dell Precision 7910 (2017 vintage). Weird because ESXi 8.0.1 installed without error.

[lamw]

JFYI - This is a known issue which has already been reported internally to Engineering and a fix has already been implemented and will be available in a future update. 

As I understood, depending on how out of sync the TSCs, you may experience different behaviors. One option that was suggested that would at least allow the booting (but subsequent crashes may still occur) is by adding tscSyncSkip=TRUE during boot up (SHIFT+O)

[MichaelSJames]

Hi, yes I tried using the customized ISO from Dell - VMware-VMvisor-Installer-8.0.0.update02-22380479.x86_64-Dell_Customized-A00. Did not make a difference but looking at the thread responses. Thanks.

[MichaelSJames]

OK, thank you all for the knowledge share and steps I could try. 

I tested out the workarounds - both boot options timerForceTSC=TRUE and tscSyncSkip=TRUE.

The results were a little different in that the boot process stated but ended up the same crash. Message is "Requested malloc size 104001552 failed, caller offset 0x453ff17f.

Please see the attached screenshot. 

Thank you to all that contributed to finding a solution. Presently running ESXi 7u3 for now as a workaround. 

MJ

[MichaelSJames]

So, I tried the following which I thought would give me the results I wanted but just when I believe ESXi should finally load I see the PSOD. So, I am going to try scripting the settings which may work better. Any guidance? 

1. Made sure Bios set to boot from UEFI USB.
2. Using Shift+O to add boot options in the following order seemed to be required: tscSyncSkip=TRUE timerForceTSC=TRUE
3. Now installer for ESXi 8.0.2 working and installed ESXi to an SSD.
4. Once ESXi 8.0.2 installed and running.
5. SSH to console and add.
6. esxcli system settings kernel set --setting=tscSyncSkip --value=TRUE
7. esxcli system settings kernel set --setting=timerForceTSC --value=TRUE
8. Reboot

Just before ESXi is up I receive the PSOD.

Almost there.

MJ

[MichaelSJames · Accepted solution]

Hi All,

1. Made sure Bios set to boot from UEFI USB.
2. Using Shift+O to add boot options in the following order seemed to be required: tscSyncSkip=TRUE timerForceTSC=TRUE
3. Now installer for ESXi 8.0.2 working and installed ESXi to an SSD.
4. Once ESXi 8.0.2 installed and running.
5. SSH to console and add the above settings as shared by the posts to the kernelopt= line. For example my kernelopt finally looks like this -
6. kernelopt=autoPartition=FALSE tscSyncSkip=TRUE timerForceTSC=TRUE
7. Reboot ESXi through the UI.
8. ESXi 8.0.2 came up successfully.

Thank you all for your support.
Made it in the end.
MJ

[brian1948]

Adding, "tscSyncSkip=TRUE timerForceTSC=TRUE", at the install boot options and the installed boot kernel did clear the PDS (PSOD) TSC message, however every reboot, the esxi host resets the password, network, hostname, etc... back to default.  ESXi 8.0.1 installation and runtime doesn't have any of the side effects, so I'll hang with the version hoping they to release the fix before to long.  Thanks for reporting.  

[mariohbrino]

@MichaelSJames wrote:

6. kernelopt=autoPartition=FALSE tscSyncSkip=TRUE timerForceTSC=TRUE

---

Thanks for the instructions, I was confused about where to change the boot.cfg file. Then I found out that the path is /bootbank/boot.cfg and everything is working perfectly now.

[GutembergRibeir]

For those who stumble into this issue, I recommend update/install the version "VMware ESXi, 8.0.2, 23305546" from April 04. That version indeed has a fix that @lamw mentioned and it worked just fine! No need for boot/kernel flags. Installer and boot works perfectly fine now!

Tested in a Dell Precision T7910 with 2x Xeon E5-2699A v4. Before this build, I got TSC out of Sync PSOD straight at the installer.

I hope it helps!