Zdravim
Mam na notase nainstalovany ubuntu 7.10, chcel som si nieco stiahnut z CD a DVD a prekvapila ma nemilo rychlost a ako sa spomalia veci v notase - zacalo sekat prehravanie mp3 (CPU 2 GHz, 512 MB RAM, IDE). Preto som zacal laborovat s hdparm. Skusil som zapnut DMA : hdparm -d1 /dev/cdrom a dostal som nasledovnu hlasku :
/dev/cdrom:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Inappropriate ioctl for device
podobne chybove hlasky dostavam aj pri inych parametroch.
Cez dmesg som vykoumal ze HDD a CDROM pristupuje masina cez SCSI (emulacia)
$ dmesg | grep scsi
[ 9.809537] scsi0 : ata_piix
[ 9.809644] scsi1 : ata_piix
[ 3.772000] scsi 0:0:0:0: Direct-Access ATA WDC WD600UE-22KV 01.0 PQ: 0 ANSI: 5
[ 3.776000] scsi 0:0:1:0: CD-ROM HL-DT-ST DVDRAM GSA-T10N PC05 PQ: 0 ANSI: 5
[ 3.820000] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 3.820000] scsi 0:0:1:0: Attached scsi generic sg1 type 5
[ 3.848000] sr0: scsi3-mmc drive: 24x/24x writer dvd-ram cd/rw xa/form2 cdda tray
[ 3.848000] sr 0:0:1:0: Attached scsi CD-ROM sr0
Takze moja otazka znie ako mozem trosku zdvihnut vykon pri diskovych operaciach ? Eventualne, da sa vypnut tento SCSI pristup ?
hdparm a SCSI emulacia
Pre pridávanie komentárov sa musíte prihlásiť.
Toto cele je sposobene zapnutym AHCI v biose. Ja som mal pred nedavnom presne opacny problem -> AHCI som mal vypnute, SATA disky mi bral ako IDE a ficalo to rychlostou 3-5MB/s (hdparm -tT). Po zapnuti AHCI to islo cca 60-70MB/s :)
Co ti vypise hdparm /dev/mojdisk ; hdparm -tT /dev/mojdisk ?
/dev/sda:
IO_support = 0 (default 16-bit)
readonly = 0 (off)
readahead = 256 (on)
geometry = 7296/255/63, sectors = 117210240, start = 0
hdparm -tT /dev/sda
/dev/sda:
Timing cached reads: 1296 MB in 2.00 seconds = 648.79 MB/sec
Timing buffered disk reads: 98 MB in 3.03 seconds = 32.36 MB/sec