MSP430F2619 has 256 bytes of information flash memory. This memory is again segmented in 4, 64 bytes segments. Segment A of this memory can't be erased during mass erase and production programming. I want to store device specific configuration data which is more than 105 bytes long. This I will store in Segment A and B. But how do I make sure that part in segment will remain even after mass erase or production programming.
At runtime the LOCKA bit protects segment A from any kind of write or erase, but it also protects the entire information memory from a mass erase operation. Its certainly possible to erase these areas during production programming but, depending on how you're doing the programming, you need to go more or less out of your way to do it. (It looks like for JTAG you'd need to explicitly clear LOCKA to do it, but the built in bootloader will clear it for you if you enter it from reset).
Also note that segment A contains some device calibration data so if you need that, don't put your data over the top of it.