ftp-download-stress01 Verify the ftp server or the kernel is not down after a ftp client requests large data via IPv4/IPv6 ftp-download-stress02 Verify the ftp server or the kernel is not down after many ftp clients request data over IPv4/IPv6 asynchronously for a long time ftp-upload-stress01 Verify the ftp server or the kernel is not down after a ftp client uploads a large data via IPv4/IPv6 ftp-upload-stress02 Verify the ftp server or the kernel is not down after many ftp clients uploads data over IPv4/IPv6 asynchronously for a long time