We have an old Dell PowerEdge 2850 server that we use in our DMZ for a FTP and Customer portal for our customers. We had a 136GB RAID1 partition and 409GB RAID5 partition. The server's OS was VMware ESXi 3.5 and it was hosting Server 2003 virtuals. One for the FTP site and one for our Customer portal. From what I gathered, one of the RAID1 drives and one of the RAID5 drives went down. Don't know the cause. After tinkering it for a while, I blew away the RAID1 partition and replaced the failed drive. The only thing on it was ESXi. The virtuals sat on the RAID5 partition. I replaced the drive and rebuilt it within the server's BIOS. When I reinstalled ESXi, it detected that the RAID5 partition was a vmfs partition. I was able to log into VMware to try and add the partition to the storage array ESXi seen that it was a vmhba1:1:0 drive with 409GB capacity. But, when I went to add it, I got the message "Unable to read partition information from this disk."
Is there any way or any tool I can use to get the data off of this partition? It is mission critical. I don't know if it's a hardware issue or if VMware simply can't read it so I'm tagging both to this question.
Do you not have any backups ? if so proceed to Data Recovery specialist - Kroll Ontrack - https://www.krollontrack.co.uk/
If you want to experiment and mess, we can recommend some tools, we have used to successfully recover virtual machine disks.