Hi folks, I have an HP Proliant 140DL G2 server with what appears to be an IDE drive in non-DMA mode. Performance on the server is extremely bad when large amounts of disk activity is taking place. I think the problem is that my drive is not in DMA mode: # hdparm /dev/hda /dev/hda: multcount = 16 (on) IO_support = 0 (default 16-bit) unmaskirq = 0 (off) using_dma = 0 (off) keepsettings = 0 (off) readonly = 0 (off) readahead = 256 (on) geometry = 16383/255/63, sectors = 80026361856, start = 0 ...but I can't set it on: # hdparm -d1 /dev/hda /dev/hda: setting using_dma to 1 (on) HDIO_SET_DMA failed: Operation not permitted using_dma = 0 (off) ...which I think is because the IDE controller isn't really recognized, or is pretending to be a SATA controller: # lspci -v | less 00:1f.2 IDE interface: Intel Corporation 82801EB (ICH5) SATA Controller (rev 02) (prog-if 8a [Master SecP PriP]) Subsystem: Hewlett-Packard Company: Unknown device 3208 Flags: bus master, 66Mhz, medium devsel, latency 0, IRQ 193 I/O ports at <unassigned> I/O ports at <unassigned> I/O ports at <unassigned> I/O ports at <unassigned> I/O ports at 1470 [size=16] All the google hits I've seen so far imply I have to build a kernel module but I'd rather not get into the business of rolling my own kernel if I don't have to. I spun through the HP support page for this box/OS combo, and I don't see any SATA/IDE/ATA drivers, only SCSI/SAS drivers. So before I continue on, can I get a sanity check here -- am I barking up the right tree? -- /\oo/\ / /()\ \ David Mackintosh | dave at xdroop.com | http://www.xdroop.com -------------- next part -------------- A non-text attachment was scrubbed... Name: not available Type: application/pgp-signature Size: 189 bytes Desc: not available URL: <http://lists.centos.org/pipermail/centos/attachments/20080602/84469a48/attachment-0004.sig>