topic Re: VMFS lost/unavailable and datastore not visible in ESXi Discussions

VMFS lost/unavailable and datastore not visible

kusane — Thu, 28 Sep 2023 08:45:42 GMT

Hi guys,

Here's what happened: Our server running ESXi version 8.0 U1 unexpectedly rebooted, and since then, we've lost access to our primary datastore. This primary datastore is home to not only the ESXi operating system but also several vital servers and VMFS volumes.

Oddly, the ESXi client/website appears to be loading correctly, and we can access other VMFS volumes on different hard drives and datastores without any issues. The real problem is that we can't seem to find our main datastore anywhere under /dev/disks or any other location within the ESXi environment.

Our top priority is to recover this main datastore without risking any of the data or VMFS volumes it contains. We need to get everything back up and running smoothly.

If you need any specific information or logs from our side to assist in the troubleshooting process, please let us know, and we'll provide them right away.

Re: VMFS lost/unavailable and datastore not visible

battybishop — Thu, 28 Sep 2023 21:04:34 GMT

Check to make sure your Datastores aren't being recognised as snapshots

SSH onto the host and run this command

"esxcli storage vmfs snapshot list"

This will return the Volume name and a VMFS UUID if there are being recognised as snapshots

Then using the UUID you can mount it using this command

esxcfg-volume -M "vmfs uuid"

Your volumes should then be available

Re: VMFS lost/unavailable and datastore not visible

kusane — Fri, 29 Sep 2023 06:32:20 GMT

Thanks for the response batty! When I run the command "esxcli storage vmfs snapshot list" it returns nothing (there is no snapshots).. Here is a snippet from our main screen under "virtual machines":

As you can see it "refers" to a volume "60226260-17ea51ee-b343-004e01a2075a" which are unavailable.

Here is a snipped of our devices under storage (it is missing the 520GB disk):

Any new advices perhaps? I am open for a remote session if that would be easier for you?

Re: VMFS lost/unavailable and datastore not visible

battybishop — Fri, 29 Sep 2023 10:16:23 GMT

If the disk isn't showing in devices then that explains why it can't see the volume, looks like you have may have some partition damage. At this level I'd recommend raising a VMware support ticket as data is at risk.

Re: VMFS lost/unavailable and datastore not visible

kusane — Mon, 02 Oct 2023 07:30:44 GMT

Thanks for your prompt reply Batty, we tried different approaches and VMware support ticket didn't help either, they think its something within the system, I have checked the partition on the disk and the data inside it seems fine and without issues.. I think it might be something within BIOS or something..!

Re: VMFS lost/unavailable and datastore not visible

battybishop — Mon, 02 Oct 2023 11:37:22 GMT

It could be a fault on the SSD as well, I found this that might help you

How to Access VMFS Datastore from Linux, Windows, or ESXi | Windows OS Hub (woshub.com)

Maybe this will allow you to extract the data from that volume to a new one, I'd definitely suggest getting another SSD and try an move the data to that in case there is something weird going on you don't want to affect your other existing datastores.

Re: VMFS lost/unavailable and datastore not visible

kusane — Mon, 02 Oct 2023 12:34:33 GMT

Thanks once again!

I took out the SSD of the machine now and attached it to my PC and can seem to be missing an "assigned" letter to some of the partitions. Here is a overview on the SSD:

This is a small draft of the files in D :

And here for E: drive:

They are nearly the same...

And I can't do anything else than "delete volume" on the 120GB+350GB partitions.

Can this be any helpful for you guys to look into?

Re: VMFS lost/unavailable and datastore not visible

battybishop — Mon, 02 Oct 2023 18:48:06 GMT

Check the guide above, the data you want will be in the two partitions windows doesn't recognize.

I've also found these

How to Mount VMFS in Linux, Windows, and ESXi (nakivo.com)

Tools to mount VMFS on Linux, ESXi, Windows | DiskInternals

They mention a windows VMFS driver but I've never used it.

Re: VMFS lost/unavailable and datastore not visible

kusane — Wed, 04 Oct 2023 08:28:00 GMT

Thanks for the help. I didn't manage to recover the data on the disk, so we ended up installing the system on a new harddrive and let the main drive (with the OS) just be left as it is!