expanding C drive in VMware

You can expand the drive but I don't know if you can expand the partition within Red Hat. For an example, for a Windows machine within VM you can expand your C: drive but the expanded space would be unallocated space the expanded space does not add space to your current Windows Partition since this is not managed by VMware but instead the OS.

Avilov can you show me how i can do the second step in details. thanks

if you run LVM, you need to  extend logical volume with "lvextend" command

check filesystem first with "e2fsck" command,
and than run "Resize2fs"

avilov, he'll need to resize the physical partition and then the physical volume first, then resize the desired logical volume, and only then resize the filesystem. None of these steps require a reboot, let alone booting from external media.

i didn't say reboot, i said umount  and if that is a  root partition he'll need to boot from external media. if that is incorrect please provide an instruction on how to unmount running root partition on live server