make buildkernel failing on zfs - fixed but now everything is slow

[Colin]

Hi again folks.

Thanks to all the suggestions I have gotten the new world/kernel up and 
running finally, unfortunately I seem to be having problems now. The 
entire system is sluggish and unresponsive. Even trying to scroll 
through a vi session jumps and pauses all the time.

Whether it is bringing up an SSH session, something through apache or 
anything else on the system is can take anywhere up to 20 second to 
respond which is not good.

top gives me the impression that its not any kind of runaway process or 
anything like that

last pid: 78629;  load averages:  0.00,  0.03,  0.06                      
116 processes: 1 running, 115 sleeping
CPU:  0.6% user,  0.0% nice,  0.6% system,  0.0% interrupt, 98.9% idle
Mem: 787M Active, 2057M Inact, 200M Wired, 101M Cache, 112M Buf, 114M Free
Swap: 8000M Total, 1708K Used, 7998M Free

There's nothing obvious that I can see in any other logfiles, are there 
any tools or other things that I can use to figure out why the system is 
so sluggish now?
Cheers
Colin.