def _get_erase_command(self, drive, pattern):
        """Return the command arguments based on the pattern.

        Erase command examples:
        1) Sanitize: "ssacli ctrl slot=0 pd 1I:1:1 modify erase
                      erasepattern=overwrite unrestricted=off forced"
        2) Zeros: "ssacli ctrl slot=0 pd 1I:1:1 modify erase
                   erasepattern=zero forced"

        :param drive: A string with comma separated list of drives.
        :param pattern: A string which defines the type of erase.
        :returns: A list of ssacli command arguments.
        """
        cmd_args = []
        cmd_args.append("pd %s" % drive)
        cmd_args.extend(['modify', 'erase', pattern])

        if pattern != 'erasepattern=zero':
            cmd_args.append('unrestricted=off')

        cmd_args.append('forced')
        return cmd_args
Return the command arguments based on the pattern.

        Erase command examples:
        1) Sanitize: "ssacli ctrl slot=0 pd 1I:1:1 modify erase
                      erasepattern=overwrite unrestricted=off forced"
        2) Zeros: "ssacli ctrl slot=0 pd 1I:1:1 modify erase
                   erasepattern=zero forced"

        :param drive: A string with comma separated list of drives.
        :param pattern: A string which defines the type of erase.
        :returns: A list of ssacli command arguments.