zfs trauma from locate?

[B. Cook]

So I've been having much trauma with zfs and i386; but it seems it's 
been narrowed down to the 'weekend'.

We leave friday and come back monday, and monday this box is not working 
properly.  Nothing has crashed, it's just slow.. but there is no load on 
the box; just deathly slow.. 2+ minutes to log in at console for example.

A reboot fixes it and it's good for another week..

I think I have narrowed it down to the weekly locate job.

So tonight I'll run it by hand and see if the box dogs again.. but 
assuming that is it..

what can I do about *that*?

bootloader.conf:

  cat -n /boot/loader.conf
      1	autoboot_delay="4"
      2	#vm.kmem_size_max="1024M"
      3	#vm.kmem_size="1024M"
      4	vm.kmem_size_max="512M"
      5	vm.kmem_size="512M"
      6	
      7	zfs_load="YES"
      8	vfs.zfs.prefetch_disable=1
      9	vfs.root.mountfrom="zfs:tank/root"
     10	vfs.zfs.arc_max="100M"
     11	
     12	accf_http_load="YES"
     13	accf_data_load="YES"

CPU: Intel(R) Pentium(R) 4 CPU 2.80GHz (2800.11-MHz 686-class CPU)
   Origin = "GenuineIntel"  Id = 0xf41  Stepping = 1
Features=0xbfebfbff<FPU,VME,DE,PSE,TSC,MSR,PAE,MCE,CX8,APIC,SEP,MTRR,PGE,MCA,CMOV,PAT,PSE36,CLFLUSH,DTS,ACPI,MMX,FXSR,SSE,SSE2,SS,HTT,TM,PBE>
   Features2=0x441d<SSE3,DTES64,MON,DS_CPL,CNXT-ID,xTPR>
   AMD Features=0x100000<NX>
   Logical CPUs per core: 2
real memory  = 3212574720 (3063 MB)
avail memory = 3140112384 (2994 MB)
ACPI APIC Table: <DELL   PE800   >


Filesystem                  Size    Used   Avail Capacity  Mounted on
tank/root                   104G     23M    104G     0%    /

devfs                       1.0K    1.0K      0B   100%    /dev

/dev/ad4s1a                 989M    196M    714M    22%    /bootdir

/dev/ad5s1a                 989M    257M    653M    28%    /mnt/bootdir

procfs                      4.0K    4.0K      0B   100%    /proc

tank/exports                130G     26G    104G    20%    /exports

tank/exports/squid          106G    1.8G    104G     2%    /exports/squid

tank2/home                  147G     55G     91G    38%    /home

tank/tmp                    104G    256K    104G     0%    /tmp

tank/usr                    110G    5.9G    104G     5%    /usr

tank/usr/obj                104G    640M    104G     1%    /usr/obj

tank/usr/ports              104G    143M    104G     0%    /usr/ports

tank/usr/ports/distfiles    104G    189M    104G     0% 
/usr/ports/distfiles

tank/usr/src                104G    156M    104G     0%    /usr/src

tank/var                    107G    2.9G    104G     3%    /var

/exports/squid is where the squid cache is, (aufs fwiw), and /home has 
over 3k user accounts for samba.

wc -l /etc/passwd
     3289 /etc/passwd

the kernel is a simple one:

# I commented out i486 and i586 in GENERIC
# and debugging

cpu     I686_CPU
ident   GENERICplus

include GENERIC

options  DEVICE_POLLING
options  HZ=1000

options  KVA_PAGES=512

options         ALTQ
options         ALTQ_CBQ        # Class Bases Queuing (CBQ)
options         ALTQ_RED        # Random Early Detection (RED)
options         ALTQ_RIO        # RED In/Out
options         ALTQ_HFSC       # Hierarchical Packet Scheduler (HFSC)
options         ALTQ_PRIQ       # Priority Queuing (PRIQ)
options         ALTQ_NOPCC      # Required for SMP build

I have a simple pf.conf with some scrub and altq settings if anyone 
thinks it might help.

but like I said I'm pretty sure it's locate now..

clues or questions appreciated.