Subject: tar makes my disks crawl.
To: None <>
From: Nigel Reed <>
List: current-users
Date: 06/22/2001 19:56:34
Another thing I've just noticed is that I'm getting dire disk performance
while using tar. Again, 1.5W kernel/userland on i386 platform.

tar cvf /dev/st0 .

As soon as I set the command going I tried to load mutt, it loads about
400 messages in about 5 seconds usually, once I had set the tar going
it look 6 seconds to load 10 mesasges.

Typing ls -l just hands me solid for about 15 seconds before it
displays the list.

I'm backing up from an IDE drive to a Hp Surestore Tape 2000. Here is
the complete dmesg for my system

NetBSD 1.5W (WIBBLE) #0: Thu Jun 21 12:56:09 CDT 2001
cpu0: Intel Celeron (Mendocino) (686-class), 534.59 MHz
cpu0: I-cache 16 KB 32b/line 4-way, D-cache 16 KB 32b/line 2-way
cpu0: L2 cache 128 KB 32b/line 4-way
cpu0: features 183f9ff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,SEP,MTRR>
cpu0: features 183f9ff<PGE,MCA,CMOV,FGPAT,PSE36,MMX,FXSR>
total memory = 127 MB
avail memory = 115 MB
using 1659 buffers containing 6636 KB of memory
BIOS32 rev. 0 found at 0xfaff0
PCI BIOS rev. 2.1 found at 0xfb020
PCI IRQ Routing Table rev. 1.0 found at 0xfdae0, size 144 bytes (7 entries)
PCI Interrupt Router at 000:07:0 (vendor 0x1106 product 0x0596)
PCI Exclusive IRQs: 10 11
mainbus0 (root)
pnpbios0 at mainbus0: nodes 15, max len 74
pckbc1 at pnpbios0 index 4 (PNP0303): kbd port
pckbc2 at pnpbios0 index 10 (PNP0F13): aux port
pckbd0 at pckbc1 (kbd slot)
pckbc1: using irq 1 for kbd slot
wskbd0 at pckbd0: console keyboard
pms0 at pckbc1 (aux slot)
pckbc1: using irq 12 for aux slot
wsmouse0 at pms0 mux 0
pci0 at mainbus0 bus 0: configuration mode 1
pci0: i/o space, memory space enabled
pchb0 at pci0 dev 0 function 0
pchb0: vendor 0x1106 product 0x0691 (rev. 0xc4)
ppb0 at pci0 dev 1 function 0: vendor 0x1106 product 0x8598 (rev. 0x00)
pci1 at ppb0 bus 1
pci1: i/o space, memory space enabled
pcib0 at pci0 dev 7 function 0
pcib0: vendor 0x1106 product 0x0686 (rev. 0x22)
pciide0 at pci0 dev 7 function 1: VIA Technologies VT82C686A (Apollo KX133) ATA66 controller
pciide0: bus-master DMA support present
pciide0: primary channel configured to compatibility mode
wd0 at pciide0 channel 0 drive 0: <QUANTUM FIREBALLP AS30.0>
wd0: drive supports 16-sector PIO transfers, LBA addressing
wd0: 28629 MB, 16383 cyl, 16 head, 63 sec, 512 bytes/sect x 58633344 sectors
wd0: 32-bit data port
wd0: drive supports PIO mode 4, DMA mode 2, Ultra-DMA mode 5 (Ultra/100)
pciide0: primary channel interrupting at irq 14
wd0(pciide0:0:0): using PIO mode 4, Ultra-DMA mode 4 (Ultra/66) (using DMA data transfers)
pciide0: secondary channel configured to compatibility mode
atapibus0 at pciide0 channel 1: 2 targets
cd0 at atapibus0 drive 0: <Memorex CRW-1622, AH1234567892123  L2, D4.0> type 5 cdrom removable
cd0: 32-bit data port
cd0: drive supports PIO mode 3, DMA mode 1
pciide0: secondary channel interrupting at irq 15
cd0(pciide0:1:0): using PIO mode 3, DMA mode 1 (using DMA data transfers)
pchb1 at pci0 dev 7 function 4
pchb1: vendor 0x1106 product 0x3057 (rev. 0x30)
auvia0 at pci0 dev 7 function 5: VIA VT82C686A AC'97 Audio (rev H)
auvia0: interrupting at irq 10
auvia0: SigmaTel STAC9721/23 codec; 18 bit DAC, 18 bit ADC, Rockwell 3D
auvia0: warning: codec doesn't support hardware AC'97 2.0 Variable Rate Audio
audio0 at auvia0: full duplex, mmap, independent
vga0 at pci0 dev 8 function 0: vendor 0x102b product 0x0519 (rev. 0x01)
wsdisplay0 at vga0: console (80x25, vt100 emulation), using wskbd0
wsdisplay0: screen 1-4 added (80x25, vt100 emulation)
de0 at pci0 dev 10 function 0
de0: interrupting at irq 10
de0: DEC DE500-XA 21140 [10-100Mb/s] pass 1.2
de0: address 00:00:f8:02:8d:54
siop0 at pci0 dev 11 function 0: Symbios Logic 53c825 (fast wide scsi)
siop0: interrupting at irq 11
scsibus0 at siop0: 16 targets, 8 luns per target
isa0 at pcib0
com0 at isa0 port 0x3f8-0x3ff irq 4: ns16550a, working fifo
com1 at isa0 port 0x2f8-0x2ff irq 3: ns16550a, working fifo
addcom0 at isa0 port 0x108-0x147 irq 5
com2 at addcom0 slave 0: ns16550a, working fifo
com3 at addcom0 slave 1: ns16550a, working fifo
com4 at addcom0 slave 2: ns16550a, working fifo
com5 at addcom0 slave 3: ns16550a, working fifo
com6 at addcom0 slave 4: ns16550a, working fifo
com7 at addcom0 slave 5: ns16550a, working fifo
com8 at addcom0 slave 6: ns16550a, working fifo
com9 at addcom0 slave 7: ns16550a, working fifo
lpt0 at isa0 port 0x378-0x37b irq 7
pcppi0 at isa0 port 0x61
sysbeep0 at pcppi0
isapnp0 at isa0 port 0x279: ISA Plug 'n Play device support
npx0 at isa0 port 0xf0-0xff: using exception 16
fdc0 at isa0 port 0x3f0-0x3f7 irq 6 drq 2
fd0 at fdc0 drive 0: 1.44MB, 80 cyl, 2 head, 18 sec
isapnp0: no ISA Plug 'n Play devices found
biomask eb45 netmask ef45 ttymask ffc7
scsibus0: waiting 2 seconds for devices to settle...
cd1 at scsibus0 target 0 lun 0: <NEC, CD-ROM DRIVE:500, 1.0> SCSI2 5/cdrom removable
cd1: async, 8-bit transfers
de0: enabling 10baseT port
st0 at scsibus0 target 5 lun 0: <HP, HP35470A, T503> SCSI2 1/sequential removable
st0: density code 19, variable blocks, write-enabled
st0: sync (200.0ns offset 8), 8-bit (5.000MB/s) transfers
st1 at scsibus0 target 6 lun 0: <EXABYTE, EXB-8200, 2618> SCSI1 1/sequential removable
st1: drive empty
st1: async, 8-bit transfers
boot device: wd0
root on wd0a dumps on wd0b
root file system type: ffs
IP Filter: v3.4.16 initialized.  Default = pass all, Logging = enabled
wsmux1: connecting to wsdisplay0