Hi. According to "hdparm -i /dev/dvd" my dvd drive is able to work in dma mode. Thus I enabled it in yast. "Model=Pioneer DVD-ROM ATAPIModel DVD-105S 012, FwRev=E1.22, SerialNo= Config={ Fixed Removeable DTR<=5Mbs DTR>10Mbs nonMagnetic } RawCHS=0/0/0, TrkSize=0, SectSize=0, ECCbytes=0 BuffType=13395, BuffSize=64kB, MaxMultSect=0 (maybe): CurCHS=0/0/0, CurSects=0, LBA=yes, LBAsects=0 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} PIO modes: pio0 pio1 pio2 pio3 pio4 DMA modes: sdma0 sdma1 sdma2 mdma0 mdma1 mdma2 UDMA modes: udma0 udma1 *udma2 AdvancedPM=no Drive conforms to: device does not report version: 1 2 3 4" But when I mount the dvd drive these lines appear in /var/log/messages. "Feb 26 01:11:51 oliver kernel: hdc: cdrom_decode_status: status=0x51 { DriveReady SeekComplete Error }Feb 26 01:11:51 oliver kernel: hdc: cdrom_decode_status: error=0xb0Feb 26 01:11:53 oliver kernel: hdc: cdrom_decode_status: status=0x51 { DriveReady SeekComplete Error }Feb 26 01:11:53 oliver kernel: hdc: cdrom_decode_status: error=0xb0Feb 26 01:11:55 oliver kernel: hdc: cdrom_decode_status: status=0x51 { DriveReady SeekComplete Error }Feb 26 01:11:55 oliver kernel: hdc: cdrom_decode_status: error=0xb0Feb 26 01:11:57 oliver kernel: hdc: cdrom_decode_status: status=0x51 { DriveReady SeekComplete Error }Feb 26 01:11:57 oliver kernel: hdc: cdrom_decode_status: error=0xb0Feb 26 01:11:57 oliver kernel: hdc: DMA disabledFeb 26 01:11:57 oliver kernel: hdc: ATAPI reset completeFeb 26 01:11:57 oliver kernel: ISO 9660 Extensions: Microsoft Joliet Level 3Feb 26 01:11:57 oliver kernel: ISO 9660 Extensions: RRIP_1991A" The computer disables dma itself. When I enable dma and udma2 together I get this message "Feb 26 01:15:42 oliver kernel: hdc: CHECK for good STATUS" But the dvd drives stays in dma and udma2 mode. Finally, this is the output of hdparm /dev/dvd HDIO_GET_MULTCOUNT failed: Invalid argument IO_support = 1 (32-bit) unmaskirq = 1 (on) using_dma = 0 (off) keepsettings = 0 (off) readonly = 1 (on) readahead = 8 (on) HDIO_GETGEO failed: Invalid argument Does anybody know why dma does not work but dma and udma2 together? What does "CHECK for good STATUS" mean? Thanks for your help, Fabian