Pomaly HDD IBM UltraATA100

[Alexandr Malusek]

Pavel Ruzicka <pavouk na k332.feld.cvut.cz> writes:

> Mam problem s nekolika harddisky IBM 30GB, 45GB, 7200rpm, UltraATA100, ze 
> jsou pod linuxem strasne pomale.

Zvlastni. Tyto disky jsem pri nakupu preferoval, protoze s nimi mam
dobre zkusenosti. Mam je na "klasickem" IDE kabelu.

PC1 (2x550 MHz PIII, 2x45 GB IBM HD):
$ /sbin/lspci
00:00.0 Host bridge: Intel Corporation 440BX/ZX - 82443BX/ZX Host bridge
00:07.1 IDE interface: Intel Corporation 82371AB PIIX4 IDE (rev 01)
$ hdparm -tT /dev/hda
 Timing buffer-cache reads:   128 MB in  0.97 seconds =131.96 MB/sec
 Timing buffered disk reads:  64 MB in  2.78 seconds = 23.02 MB/sec
$ hdparm -tT /dev/hdb
 Timing buffer-cache reads:   128 MB in  0.97 seconds =131.96 MB/sec
 Timing buffered disk reads:  64 MB in  2.79 seconds = 22.94 MB/sec

PC2 (2x866 MHz PIII, 30 GB IBM HD)
$ /sbin/lspci
00:07.1 IDE interface: VIA Technologies, Inc. VT82C586 IDE [Apollo] (rev 10)
$ hdparm -tT /dev/hda
 Timing buffer-cache reads:   128 MB in  0.93 seconds =137.63 MB/sec
 Timing buffered disk reads:  64 MB in  2.85 seconds = 22.46 MB/sec

U PC2 bych ho mohl pripojit i na ATA100, ale to PC funguje jako
bezdiskovy node v PC clusteru, takze to pro me nema valny vyznam.

> Konkretne merenim hdparm -t /dev/hda ukazuje rychlost kolem 2,5MB/s.

Takovou rychlost nedosahnu ani pri vypnutem using_dma:

$ hdparm /dev/hda
/dev/hda:
 multcount    =  0 (off)
 I/O support  =  0 (default 16-bit)
 unmaskirq    =  0 (off)
 using_dma    =  0 (off)
 keepsettings =  0 (off)
 nowerr       =  0 (off)
 readonly     =  0 (off)
 readahead    =  8 (on)
 geometry     = 3328/255/63, sectors = 53464320, start = 0

$ hdparm -t /dev/hda
 Timing buffered disk reads:  64 MB in 17.19 seconds =  3.72 MB/sec

> Je problem v jadre? V disku?

Nevim, pod ATA100 jsem to netestoval. Jadro mam obstarozni
2.2.16-SMP. Asi bych zkusil disky dat na stare IDE, je mozne ze s
ATA100 jsou nejake problemy.

--
A. Malusek  (malusek na ujf.cas.cz)
UJF AV CR