I have a NAS that uses Active Directory users as authentication and 2 VMs that mount a share on there on boot via /etc/fstab like so:
//10.0.0.100/docs /mnt/cifs/apps cifs username=domainuser,password=thepassword,domain=office,iocharset=utf8,sec=ntlm 0 0
After a power outage they would no longer mount on boot, normally this just means they booted faster than the NAS and a quick reboot on the CentOS VMs fixes the issue. This is not working this time, I've reset the NAS and VMs, I've made sure that I can access the NAS from other workstations, can login with domain credentials, etc.
Only other oddity was that someone changed the names of the Virtual Machine Port Groups in ESXi (Basically removed underscores, so Private_LAN became Private LAN) before the power outage, so when the ESXi host came back online I noticed that all networking was down, checked the settings of the VMs and as it was pointing to the old name all the NICs were not connected, I of course reconnected them all to the new port groups and turned the NIC back on.
I can ping the NAS from the VMs, etc. but reboot after reboot I cannot get them to mount the share. I made sure everything came up in the correct order (DC first for auth, NAS 2nd and VMs 3rd).