I had issue mounting one of Linux system, lost root Password.

Which SET Grub setting as 0, which not give you to enter in to single user mode.

here is the steps for recovering.

Download KNOPPIX_V7.2.0CD-2013-06-16-EN.iso
Upload to Esxi one of the Folder where you have access for this ISO to Boot.
Stop the VM
Add ISO Image as CD in to the VM as Show as below. ( Connect and Power on, Select the ISO Image which was uploaded your folder/

5. Select Boot Option.

6. Select Boot Option CD ROM, how you setup in BIOS

7. Boot with Live CD and Mount the VM Drive

8. Login and try below command to scan LVM

lvmdiskscan

/dev/ram0 [ 64.00 MiB]
/dev/eve-ng-vg/root [ 71.52 GiB]
/dev/ram1 [ 64.00 MiB]
/dev/sda1 [ 487.00 MiB]
/dev/eve-ng-vg/swap_1 [ 8.00 GiB]
/dev/ram2 [ 64.00 MiB]
/dev/ram3 [ 64.00 MiB]
/dev/ram4 [ 64.00 MiB]
/dev/ram5 [ 64.00 MiB]
/dev/sda5 [ 39.52 GiB] LVM physical volume
/dev/ram6 [ 64.00 MiB]
/dev/ram7 [ 64.00 MiB]
/dev/ram8 [ 64.00 MiB]
/dev/ram9 [ 64.00 MiB]
/dev/ram10 [ 64.00 MiB]
/dev/ram11 [ 64.00 MiB]
/dev/ram12 [ 64.00 MiB]
/dev/ram13 [ 64.00 MiB]
/dev/ram14 [ 64.00 MiB]
/dev/ram15 [ 64.00 MiB]
/dev/sdb [ 40.00 GiB] LVM physical volume
1 disk
18 partitions
1 LVM physical volume whole disk
1 LVM physical volume