3ware 9550SXU-4LP a vysoke i/o wait pri zapise

Zdravim, mam v serveri (ASUS RS120-E4/PA4) 3ware 9550SXU-4LP (PCI-X verzia), kde su pripojene styri disky WDC5001ABYS nakonfigorovane do RAID5. Stripe size pola je 64kB, cache je zapnuta, je nastaveny performance profil. Pri read operaciach to ide relativne dobre, ale pri operaciach s databazou (insert, update...), pri kopirovani/kompilovani idu i/o wait na 80-100% a tiez aj napr. ked vypinam apache a dost dlho trva aj ls na adresar. Nasiel som v 3ware KB nejake veci ktore treba nastavit, ale malo to minimalny ucinok. V prilohe je config mojho jadra. Kde moze byt problem? Dik

Vypis konfiguracie raidu:

hostname ~ # tw_cli
//hostname> /c0 show all
/c0 Driver Version = 2.26.08.003-2.6.23
/c0 Model = 9550SXU-4LP
/c0 Available Memory = 112MB
/c0 Firmware Version = FE9X 3.08.00.016
/c0 Bios Version = BE9X 3.08.00.004
/c0 Boot Loader Version = BL9X 3.02.00.001
/c0 Serial Number = 
/c0 PCB Version = Rev 032
/c0 PCHIP Version = 1.60
/c0 ACHIP Version = 1.90
/c0 Number of Ports = 4
/c0 Number of Drives = 4
/c0 Number of Units = 1
/c0 Total Optimal Units = 1
/c0 Not Optimal Units = 0
/c0 JBOD Export Policy = off
/c0 Disk Spinup Policy = 1
/c0 Spinup Stagger Time Policy (sec) = 1
/c0 Auto-Carving Policy = off
/c0 Auto-Carving Size = 2048 GB
/c0 Auto-Rebuild Policy = on
/c0 Controller Bus Type = PCIX
/c0 Controller Bus Width = 64 bits
/c0 Controller Bus Speed = 133 Mhz

Unit  UnitType  Status         %RCmpl  %V/I/M  Stripe  Size(GB)  Cache  AVrfy
------------------------------------------------------------------------------
u0    RAID-5    OK             -       -       64K     1396.95   ON     OFF

Port   Status           Unit   Size        Blocks        Serial
---------------------------------------------------------------
p0     OK               u0     465.76 GB   976773168     WD-WCAS
p1     OK               u0     465.76 GB   976773168     WD-WCAS
p2     OK               u0     465.76 GB   976773168     WD-WCAS
p3     OK               u0     465.76 GB   976773168     WD-WCAS

//hostname> /c0/u0 show all
/c0/u0 status = OK
/c0/u0 is not rebuilding, its current state is OK
/c0/u0 is not verifying, its current state is OK
/c0/u0 is initialized.
/c0/u0 Cache State = on
/c0/u0 volume(s) = 1
/c0/u0 name = hostname
/c0/u0 serial number = 
/c0/u0 Ignore ECC policy = off
/c0/u0 Auto Verify Policy = off
/c0/u0 Storsave Policy = performance
/c0/u0 Command Queuing Policy = on

Unit     UnitType  Status         %RCmpl  %V/I/M  Port  Stripe  Size(GB)
------------------------------------------------------------------------
u0       RAID-5    OK             -       -       -     64K     1396.95
u0-0     DISK      OK             -       -       p3    -       465.651
u0-1     DISK      OK             -       -       p2    -       465.651
u0-2     DISK      OK             -       -       p1    -       465.651
u0-3     DISK      OK             -       -       p0    -       465.651
u0/v0    Volume    -              -       -       -     -       1396.95

uname:

Linux hostname 2.6.23-hardened-r8 #6 SMP Fri Mar 21 13:37:11 CET 2008 x86_64 Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz GenuineIntel GNU/Linux

a /proc/interrupts

           CPU0       CPU1       CPU2       CPU3       
  0:    7658974          0          0          0   IO-APIC-edge      timer
  1:          2          0          0          0   IO-APIC-edge      i8042
  4:        821          0          0          0   IO-APIC-edge      serial
  8:          0          0          0          0   IO-APIC-edge      rtc
  9:          0          0          0          0   IO-APIC-fasteoi   acpi
 12:          3          0          0          0   IO-APIC-edge      i8042
 14:         78          0          0          0   IO-APIC-edge      ide0
 19:          0          0          0          0   IO-APIC-fasteoi   uhci_hcd:usb3
 23:          0          0          0          0   IO-APIC-fasteoi   ehci_hcd:usb1, uhci_hcd:usb2
 24:    3796921          0          0          0   IO-APIC-fasteoi   3w-9xxx
380:   31930960          0          0          0   PCI-MSI-edge      eth0
NMI:          0          0          0          0 
LOC:    7591290    7591295    7625528    7625510 
ERR:          0

Dotaz: 3ware 9550SXU-4LP a vysoke i/o wait pri zapise