I have a system connected to a SAN via Fibre Channel interface. The system sees 3 disk sdb, sdc and sdd. I put them in a volume group and then allocated some logical volumes. If I use the logical volume to read and write to directly for my application, if there is an error on a write, I assume the write system call will return an error. Or does the write give a good return value after putting the data in some system buffer to be written later? Then is the write of the system buffer fails later, my program would not know.