Passwort:
linux-jepj:/home/guro123 # hdparm -A
-A: missing value (0/1)
hdparm - get/set hard disk parameters - version v6.3
Usage: hdparm [options] [device] ..
Options:
-a get/set fs readahead
-A set drive read-lookahead flag (0/1)
-b get/set bus state (0 == off, 1 == on, 2 == tristate)
-B set Advanced Power Management setting (1-255)
-c get/set IDE 32-bit IO setting
-C check IDE power mode status
-d get/set using_dma flag
--direct use O_DIRECT to bypass page cache for timings
-D enable/disable drive defect management
-E set cd-rom drive speed
-f flush buffer cache for device on exit
-g display drive geometry
-h display terse usage information
-i display drive identification
-I detailed/current information directly from drive
--Istdin read identify data from stdin as ASCII hex
--Istdout write identify data to stdout as ASCII hex
-k get/set keep_settings_over_reset flag (0/1)
-K set drive keep_features_over_reset flag (0/1)
-L set drive doorlock (0/1) (removable harddisks only)
-M get/set acoustic management (0-254, 128: quiet, 254: fast) (EXPERIMENTAL)
-m get/set multiple sector count
-n get/set ignore-write-errors flag (0/1)
-p set PIO mode on IDE interface chipset (0,1,2,3,4,...)
-P set drive prefetch count
-q change next setting quietly
-Q get/set DMA tagged-queuing depth (if supported)
-r get/set device readonly flag (DANGEROUS to set)
-R register an IDE interface (DANGEROUS)
-S set standby (spindown) timeout
-t perform device read timings
-T perform cache read timings
-u get/set unmaskirq flag (0/1)
-U un-register an IDE interface (DANGEROUS)
-v defaults; same as -mcudkrag for IDE drives
-V display program version and exit immediately
-w perform device reset (DANGEROUS)
-W set drive write-caching flag (0/1) (DANGEROUS)
-x tristate device for hotswap (0/1) (DANGEROUS)
-X set IDE xfer mode (DANGEROUS)
-y put IDE drive in standby mode
-Y put IDE drive to sleep
-Z disable Seagate auto-powersaving mode
-z re-read partition table
--security-help display help for ATA security commands
linux-jepj:/home/guro123 # hdparm -A /dev/hdd
-A: missing value (0/1)
/dev/hdd:
linux-jepj:/home/guro123 # hdparm -d /dev/hdd
/dev/hdd:
using_dma = 0 (off)
linux-jepj:/home/guro123 # hdparm -A1 /dev/hdd
/dev/hdd:
setting drive read-lookahead to 1 (on)
HDIO_DRIVE_CMD(setreadahead) failed: Input/output error
linux-jepj:/home/guro123 # hdparm -d /dev/hdd
/dev/hdd:
using_dma = 0 (off)
linux-jepj:/home/guro123 #
Also ist der richtige Befehl:-d Disable/enable the "using_dma" flag for this drive. This option now works with most combinations of drives and PCI interfaces which support DMA and which are
known to the kernel IDE driver. It is also a good idea to use the appropriate -X option in combination with -d1 to ensure that the drive itself is programmed
for the correct DMA mode, although most BIOSs should do this for you at boot time. Using DMA nearly always gives the best performance, with fast I/O throughput
and low CPU usage. But there are at least a few configurations of chipsets and drives for which DMA does not make much of a difference, or may even slow things
down (on really messed up hardware!). Your mileage may vary.
Unter DMA (übersetzt direkter Speicherzugriff) ist eine Schaltungs- und Steuermaßnahme zu verstehen, die über spezielle Datenleitungen auf dem Motherboard eine Verbindung zwischen Steckkarten und dem Arbeitsspeicher herstellen. Dadurch können die Daten ohne Umweg über den Prozessor direkt in den Speicher geschrieben werden. So läßt sich die Ausführungsgeschwindigkeit erhöhen.