"virtual machine restore file write failed" gave a few results. Maybe worth a look?
vStorage restore to a thin provisioned disk using SAN transport mode may fail with "Virtual machine restore: file write failed"
http://www.symantec.com/business/support/index?page=content&id=TECH144235
vStorage restores fails with "file write failed" "You have requested access to an area of the virtual disk that is out of bounds (17)."
http://www.symantec.com/business/support/index?page=content&id=TECH140080
VMWare restore fails with STATUS 5
http://www.symantec.com/business/support/index?page=content&id=TECH148342
plus
https://www-secure.symantec.com/connect/forums/netbackup-7-vsphere-41-restoring-vmdk-issue
Maybe give you something to go on? Sorry, no personal experience so apologies if these bear no relevance to your exact situation.