Amazingly slow disk writes

[Eric Mertens <emmf26_(_at_)_umr_(_dot_)_edu>]

Hi,

I've noticed that when I try to untar an archive when a moderate number
of files, that my drive activity light goes solid, but the transer goes
incredably slow... I don't know what to report, I'm hoping that someone
has some insight or ideas.  The drive did not originally go this slow
when I installed (and i have checked the drive with the manufacturer
provided utility and it tests alright, and takes about the same time as
my other two drives)

This is only happening on /dev/wd0g

Thank you for your time,
-- eric

`df` output
Filesystem  512-blocks     Used    Avail Capacity  Mounted on
/dev/wd0a       147998    50002    90598    36%    /
/dev/wd0f       197934        6   188032     0%    /tmp
/dev/wd0d      6091698  2015548  3771566    35%    /usr
/dev/wd0e       197934    16600   171438     9%    /var
/dev/wd0g    219849064 177721080 31135532    85%    /home
/dev/wd1a    226998216 213758310  1889996    99%    /home/pikapps/disk2
/dev/wd2a    226998216 212186598  3461708    98%    /home/pikapps/disk3
mfs:24743        96382        2    91562     0%    /mnt

`iostat` output while untar-ing
      tty            wd0             wd1             wd2             fd0
           cpu
 tin tout  KB/t t/s MB/s   KB/t t/s MB/s   KB/t t/s MB/s   KB/t t/s MB/s
us ni sy in id
   1   73 13.03  15 0.19  63.24   1 0.04  36.96   0 0.01   0.00   0 0.00
 0  0  1  1 98 

`dmesg` output
OpenBSD 3.3-current (FSERV) #0: Tue Apr 29 08:13:31 CDT 2003
    root_(_at_)_fserv_(_dot_)_pikapphi_(_dot_)_umr_(_dot_)_edu:/usr/src/sys/arch/i386/compile/FSERV
cpu0: AMD Athlon XP Model 8 (Thoroughbred) ("AuthenticAMD" 686-class)
1.48 GHz
cpu0:
FPU,V86,DE,PSE,TSC,MSR,PAE,MCE,CX8,SYS,MTRR,PGE,MCA,CMOV,PAT,PSE36,MMX,FXSR,SIMD
real mem  = 267943936 (261664K)
avail mem = 246026240 (240260K)
using 3296 buffers containing 13500416 bytes (13184K) of memory
mainbus0 (root)
bios0 at mainbus0: AT/286+(22) BIOS, date 03/01/02, BIOS32 rev. 0 @
0xf0bf0
apm0 at bios0: Power Management spec V1.2 (BIOS mgmt disabled)
apm0: AC on, battery charge unknown
pcibios0 at bios0: rev. 2.1 @ 0xf0000/0x1462
pcibios0: PCI IRQ Routing Table rev. 1.0 @ 0xf13a0/192 (10 entries)
pcibios0: PCI Interrupt Router at 000:17:0 ("VIA VT82C586 PCI-ISA" rev
0x00)
pcibios0: PCI bus #1 is the last bus
bios0: ROM list: 0xc0000/0x8000 0xcc000/0x800 0xd0000/0x1800
0xec000/0x4000!
pci0 at mainbus0 bus 0: configuration mode 1 (no bios)
pchb0 at pci0 dev 0 function 0 "VIA VT8366 Host-PCI" rev 0x00
ppb0 at pci0 dev 1 function 0 "VIA VT8366 PCI-AGP" rev 0x00
pci1 at ppb0 bus 1
vga0 at pci1 dev 0 function 0 "ATI Rage 128 Pro TF" rev 0x00
wsdisplay0 at vga0: console (80x25, vt100 emulation)
wsdisplay0: screen 1-5 added (80x25, vt100 emulation)
cmpci0 at pci0 dev 5 function 0 "C-Media Electronics CMI8738/C3DX Audio"
rev 0x10: irq 5
audio0 at cmpci0
fxp0 at pci0 dev 15 function 0 "Intel 82557" rev 0x05: irq 12, address
00:08:c7:6b:d8:61
inphy0 at fxp0 phy 1: i82555 10/100 media interface, rev. 0
fxp1 at pci0 dev 16 function 0 "Intel 82557" rev 0x08: irq 5, address
00:02:b3:4c:41:d5
inphy1 at fxp1 phy 1: i82555 10/100 media interface, rev. 4
pcib0 at pci0 dev 17 function 0 "VIA VT8366 PCI-ISA" rev 0x00
pciide0 at pci0 dev 17 function 1 "VIA VT82C571 IDE" rev 0x06: ATA100,
channel 0 configured to compatibility, channel 1 configured to
compatibility
wd0 at pciide0 channel 0 drive 0: <WDC WD1200JB-00CRA1>
wd0: 16-sector PIO, LBA, 114473MB, 16383 cyl, 16 head, 63 sec, 234441648
sectors
wd1 at pciide0 channel 0 drive 1: <WDC WD1200JB-00CRA1>
wd1: 16-sector PIO, LBA, 114473MB, 16383 cyl, 16 head, 63 sec, 234441648
sectors
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 5
wd1(pciide0:0:1): using PIO mode 4, Ultra-DMA mode 5
wd2 at pciide0 channel 1 drive 1: <WDC WD1200JB-00CRA1>
wd2: 16-sector PIO, LBA, 114473MB, 16383 cyl, 16 head, 63 sec, 234441648
sectors
wd2(pciide0:1:1): using PIO mode 4, Ultra-DMA mode 5
"VIA VT83C572 USB" rev 0x1b at pci0 dev 17 function 2 not configured
"VIA VT83C572 USB" rev 0x1b at pci0 dev 17 function 3 not configured
"VIA VT83C572 USB" rev 0x1b at pci0 dev 17 function 4 not configured
isa0 at pcib0
isadma0 at isa0
pckbc0 at isa0 port 0x60/5
pckbd0 at pckbc0 (kbd slot)
pckbc0: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard, using wsdisplay0
pcppi0 at isa0 port 0x61
midi0 at pcppi0: <PC speaker>
sysbeep0 at pcppi0
lpt0 at isa0 port 0x378/4 irq 7
npx0 at isa0 port 0xf0/16: using exception 16
pccom0 at isa0 port 0x3f8/8 irq 4: ns16550a, 16 byte fifo
pccom0: console
pccom1 at isa0 port 0x2f8/8 irq 3: ns16550a, 16 byte fifo
fdc0 at isa0 port 0x3f0/6 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB 80 cyl, 2 head, 18 sec
biomask c040 netmask d060 ttymask d0e2
pctr: user-level cycle counter enabled
mtrr: Pentium Pro MTRR support
dkcsum: wd0 matched BIOS disk 80
dkcsum: wd1 matched BIOS disk 81
dkcsum: wd2 matched BIOS disk 82
root on wd0a
rootdev=0x0 rrootdev=0x300 rawdev=0x302