set scratch partition (back) to /tmp for esxi 7.x and esxi8.x

[Ron Albrecht]

I am looking for help/guidance on how to do this (Solved: ESXI 6.7 Removing Datastore: Setting Scratch locat... - VMware Technology Network VMTN) in a vsphere7/8 environment. My environment specific caveats - it is a 4-node self-managed vsan cluster (meaning vcenter sits on top of the vsan it manages) where esxi is deployed to an sd card. During deployment, a temporary local datastore is created. In some instances a coredump gets created and recovering from that following instructions linked above do not produce the expected result. The scratch partition gets repointed to the local datastore after every reboot, so the local datastore can never be deleted. I wouuld prefer to permanently disable the coredump (like Permanently disable ESXi coredump file (74537) (vmware.com)) but this no longer works either. So Im looking for a way to keep the scratch partition on /tmp (even when a local datastore is peresent).

[Lalegre]

,.

You could update ScratchConfig.ConfiguredScratchLocation and point to /tmp. This can be changed from ESXi Advanced System Settings on each four of them.

Have you tried this option already?

[Ron Albrecht]

,

Thx for the quick response!

I did update that setting, which requires a reboot to take effect. Upon rebooting, the setting ScratchConfig.CurrentScratchLocation and ConfiguredScratchLocation are set back to the local datastore. This change worked (I think) until 7.x when the ESXi system storage layout changed.

I am trying to remove the local datastore (is was temporary) but it seems to be in a state where I cannot go back ... unless of course I am missing something ...

[Lalegre]

,

I was reading a little bit more and testing myself, and it seems that you cannot simply redirect back to /tmp and expect the /scratch to be re-created (Do not know why). Try the following:

1. mkdir /tmp/scratch

2. Update ScratchConfig.CurrentScratchLocation with /tmp/scratch

3. reboot

Let me know how it goes.

 

[Ron Albrecht]

,

Thanks for the detail.! I will give it a go ... I opened a tkt with GSS and they agreed with your approach ...

I will follow up with results (for others) ...

 

Thx again for the help!!

 

[AnaghB]

Hello  ,

The partition will always point to a directory so we will need a directory inside the /tmp location. Please follow the below steps.

1. Take SSH session of Esxi host using root and run the command mkdir /tmp/scratch - This will create a directory named scratch under /tmp folder

2. Goto Esxi configuration setting and Update ScratchConfig.CurrentScratchLocation with /tmp/scratch

3. reboot

Do let me know the results.

 

[Ron Albrecht]

 - thx for the information. I finally got the chance to get back to this ... I did confirm that manually creating the /tmp/scratch partition does the trick. 

What I was trying to shed light on is ... why in previous releases I did not have to do this? I guess it's possible that in 7.x and later the OS partitioning and file system changed on esxi which may now require the added configuration (and it only affects those who have cfg'ed scratch to ramdisk (b/c esxi is installed on sd cards) ...

In previous versions I never had to specifically create the scratch directory ... as if setting the advanced setting defaulted to (create if doesn't exist) the scratch folder within /tmp ... and maybe it no longer does that ... 

Oh well ...  now the next hurdle ... figuring out how to tackle this with (Get-Esxcli) - so I can keep it all nice and tidy in the same script block ...

I thought it was $esxcli.esxcli.command("mkdir /tmp/scratch") ... but it wasn't

I'll post again when I find the correct line ... 

[AnaghB]

Hello  ,

Generally when we install Esxi the default location is tmp but we need to create a folder manually inside the tmp directory to save the scratch partition.

The mkdir is not an esxcli command but its a direct command to only create a directory inside tmp location.

 

[Robin Harmsen]

Did you manage to create the needed folder through PowerCLI?
We are going to need to go through 74 hosts, and enableing ssh, loging in and doing the mkdir takes quite the time.
Would save lots of time if we can simplify some stuff

[Ron Albrecht]

  I just noticed that you say to change the value of ScratchConfig.CurrentScratchLocation. Did you mean ScratchConfig.ConfiguredScratchLocation?

 

[AnaghB]

Hello  ,

 

Yes the Current Scratch config on Esxi. The changes will take place post reboot.

 

[Ron Albrecht]

That's what I thought the ScratchConfig.ConfiguredScratchLocation option did. When I try to modify the CurrentScratchLocation, an error is thrown ... 

[AnaghB]

Hello  ,

 

We can only change configured setting.. Post reboot the current and configured setting should show same value.