Disk Performance
I am currently playing around with vmware, running win98. However, the
performance stinks (I am using a beta release though). The strange thing
is though that if I do a
find / -print > /dev/null
in another window, the performance IMPROVES...
Now I am worried that there is a bigger question here...
My / files are all on a SCSI disk, while vmware runs off an IDE drive.
Could this have something to do with interrupts? Or DMA settings?
Any thoughts?
My IDE drive is an UIDE drive, but I cannot find a way to tell the kernel.
Does it automatically know? Its a Quantum Fireball 10GByte. It seems
to know it is dma (using_dma is set).
Here is my /proc/ide/ide1/hdc/settings...
name value min max mode
---- ----- --- --- ----
bios_cyl 19885 0 65535 rw
bios_head 16 0 255 rw
bios_sect 63 0 63 rw
breada_readahead 4 0 127 rw
bswap 0 0 1 r
file_readahead 124 0 2097151 rw
io_32bit 0 0 3 rw
keepsettings 0 0 1 rw
max_kb_per_request 64 1 127 rw
multcount 0 0 8 rw
nice1 1 0 1 rw
nowerr 0 0 1 rw
pio_mode write-only 0 255 w
slow 0 0 1 rw
unmaskirq 0 0 1 rw
using_dma 1 0 1 rw
what is nice1? and pio_mode write-only looks curious...
Here is the output from hdparm -i /dev/hdc
/dev/hdc:
Model=QUANTUM FIREBALL CX10.2A, FwRev=A3F.0B00, SerialNo=833920130551
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs }
RawCHS=19885/16/63, TrkSize=32256, SectSize=21298, ECCbytes=4
BuffType=3(DualPortCache), BuffSize=418kB, MaxMultSect=16, MultSect=off
DblWordIO=no, maxPIO=2(fast), DMA=yes, maxDMA=2(fast)
CurCHS=19885/16/63, CurSects=20044080, LBA=yes
LBA CHS=621/512/63 Remapping, LBA=yes, LBAsects=20044080
tDMA={min:120,rec:120}, DMA modes: mword0 mword1 *mword2
IORDY=on/off, tPIO={min:120,w/IORDY:120}, PIO modes: mode3 mode4
UDMA modes: mode0 mode1 mode2
Here is the output from hdparm /dev/hdc
/dev/hdc:
multcount = 0 (off)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 19885/16/63, sectors = 20044080, start = 0
I guess hdparm -c 1 -m 16 might improve things, but why does it go faster
when I use the scsi disk??
/proc/interrupts is
CPU0
0: 6189709 XT-PIC timer
1: 11676 XT-PIC keyboard
2: 0 XT-PIC cascade
4: 89680 XT-PIC serial
5: 146029 XT-PIC aic7xxx
8: 1539593 XT-PIC rtc
9: 265750 XT-PIC eth0
10: 1 XT-PIC soundblaster
13: 1 XT-PIC fpu
15: 44096 XT-PIC ide1
NMI: 0
ERR: 0
During bootup, the kernel (2.2.12) reports...
PIIX3: IDE controller on PCI bus 00 dev 39
PIIX3: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xffa0-0xffa7, BIOS settings: hda:pio, hdb:pio
ide1: BM-DMA at 0xffa8-0xffaf, BIOS settings: hdc:pio, hdd:pio
/dev/hdc is not detected by the bios. Incidentally, if I let the bios
detect the disk, the kernel starts hunting for /dev/hda, which causes a delay
of 10 seconds or more during bootup (I only have one IDE disk). Even then,
the BIOS never reports that it is a DMA disk (it can
detects the mode automatically only). Surely this delay indicates a problem
with the kernel?
All help appreciated. I have checked the HOWTOs, but they are seriously lacking
in useful information concerning this...
G.
--
Gordon Russell
http://www.dcs.napier.ac.uk/~gor
PGP Public Key - http://www.dcs.napier.ac.uk/~gor/pgpkey.txt
Reply to: