import re


def is_valid_vpsa_internal_name(vpsa_internal_id):
    """
    Validates a VPSA internal ID. A valid VPSA internal ID should look
    like: vsa-00000001 - It should always start with "vsa-" and end with 8
    hexadecimal characters in lower case.

    :type vpsa_internal_id: str
    :param vpsa_internal_id: The VPSA internal ID to be validated.

    :rtype: bool
    :return: True or False depending on whether vpsa_internal_id passes
     validation.
    """
    if vpsa_internal_id is None:
        return False
    match = re.match(r'^vsa-[0-9a-f]{8}$', vpsa_internal_id)

    if not match:
        return False

    return True