Como "val0x00ff" já compartilhou o link que contém a resposta exata:
communities.vmware.com/thread/492752
Once you've changed the disk's size in VMware and did not reboot your server, rescan your SCSI devices as such. First, check the name(s) of your scsi devices.
$ ls /sys/class/scsi_device/
Then rescan the scsi bus. Below you can replace the '0:0:0:0′ with the actual scsi bus name found with the previous command. Each colon is prefixed with a slash, which is what makes it look weird.
$ echo 1 > /sys/class/scsi_device/0:0:0:0/device/rescan
That will rescan the current scsi bus and the disk size that has changed will show up.