我的硬盘怎么没法打开DMA ，请高手指点!

Kinwa

我的是版本Redhat7.2，以root身份登入后运行
hdparm -d 1 /dev/hda
提示：
   dev/hda
        setting using_dma to (on)
        HDIO_SET_DMA faild :Operation not permitted
请问是怎么回事。

d00m3d

Please show us your result of

hdparm -i /dev/hda

Kinwa

我用 hdparm  -v /dev/hda
Multcont    =16 (on)
I/O Support =1  (32bit)
umaskirq    =1  (on)
using_dma   =0  (off)
keepsettings=0  (off)
nowerr      =0  (off)
readonly    =0  (off)
readahead   =8  (0n)
geometry    =1011/255/63  sectors =160836480, start=0

d00m3d

No, hdparm -v /dev/hda cannot see the supported DMA modes, pls show the results of

hdparm -i /dev/hda

Kinwa

/dev/hda:

del=IC35L080AVVA07-0, FwRev=VA4OA52A, SerialNo=VNC402A4GL0T6A
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=52
BuffType=DualPortCache, BuffSize=1863kB, MaxMultSect=16, MultSect=16
CurCHS=4047/16/255, CurSects=-217054981, LBA=yes, LBAsects=160836480
IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2
AdvancedPM=yes: disabled (255)
Drive Supports : ATA/ATAPI-5 T13 1321D revision 1 : ATA-2 ATA-3 ATA-4 ATA-5
/dev/hdd:

Model=Maxtor 6Y120L0, FwRev=YAR41BW0, SerialNo=Y3L9J1RE
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
CurCHS=4047/16/255, CurSects=-217054981, LBA=yes, LBAsects=240121728
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6
AdvancedPM=yes: disabled (255)
Drive Supports : ataATA-1 ATA-2 ATA-3 ATA-4 ATA-5 ATA-6 ATA-7

Kinwa

非常感谢d00m3d这么热心帮助！

Kinwa

我看到两个硬盘的参数感到很奇怪，为什么我的hda只能工作到udma2
而hdd却能到udma6，我在windows下看一个是工作在udma5 一个是工作在udma6.

d00m3d

最初由 Kinwa 发表
/dev/hda:

del=IC35L080AVVA07-0, FwRev=VA4OA52A, SerialNo=VNC402A4GL0T6A
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=52
BuffType=DualPortCache, BuffSize=1863kB, MaxMultSect=16, MultSect=16
CurCHS=4047/16/255, CurSects=-217054981, LBA=yes, LBAsects=160836480
IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2
AdvancedPM=yes: disabled (255)
Drive Supports : ATA/ATAPI-5 T13 1321D revision 1 : ATA-2 ATA-3 ATA-4 ATA-5
/dev/hdd:

Model=Maxtor 6Y120L0, FwRev=YAR41BW0, SerialNo=Y3L9J1RE
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
CurCHS=4047/16/255, CurSects=-217054981, LBA=yes, LBAsects=240121728
IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6
AdvancedPM=yes: disabled (255)
Drive Supports : ataATA-1 ATA-2 ATA-3 ATA-4 ATA-5 ATA-6 ATA-7

Well, you got a very nice harddisk (hdd)!  It supports many DMA modes.  hda is older but it should be able to open DMA mode.

I believe you have no problems with hdd.  I suspect your hdparm in RH7.2 may be toooooooo old to support it.  Try:

1.  upgrade your hdparm to a newer version, at least 5.4+
2.  get a Linux LiveCD such as Knoppix, boot it up and verify if the DMA mode can be open
3.  harddisk without DMA can painfully penalize performance, below is the command I usually use.  You can use it to temporarily improve your harddisk performance a little bit

hdparm -c1 -d1 -u1 -m16 -a1024  /dev/hda

-X option may also be used.  It can greatly enhance the data transmission rate.  -X66 corresponding to ATA66 but I forgot what is corresponding to ATA100, -X69?

I know -d1 does not work, please don't worry.  Based on your hdparm -v information, -u1 and -m16 is already enabled.  The -a1024 will improve your reading performance.

Kinwa

还是不行，我下载了一个hdparm5.5,看来只能升级内核了。还有-a1024,这个参数不行。我这所以装7.2是因为有很多EDA工具都指定在redhat7.2下运行，不知道升级内核后会不会有问题。

d00m3d

Can those options work with your hdd? i.e.

hdparm -c1 -d1 -u1 -m16 -a1024 /dev/hdd

I forget what other utilities may related to harddisk operations.

However, before you make any changes to your system, I suggest you to verify it again with a Knoppix LiveCD.