Serious I/O problems (bad performance and live-lock)

[Scott Long]

Daniel Eriksson wrote:
> Scott Long wrote:
> 
> 
>>What happens if you turn off mpsafevfs?
> 
> 
> At first I thought it had cured the problem, but after running 'dd' for ~3
> minutes it started swapping, and about a minute later the system became
> completely unresponsive.
> 
> Also, if I abort 'dd' after the swapping has started but before it
> live-locks it seems that a new 'dd' will take the system to that
> unresponsive state very quickly.
> 
> I tested this on the UP system, newly rebooted. The system itself is pretty
> basic. More discs than normal, but they were not mounted (they are normally
> exported using ggate). Below is the dmesg just in case...
> 
> /Daniel Eriksson
> 

Ok, next test would be to turn off mpsafevm.  This is just a simple
guess, though, but and changes in the behaviour would be very
interesting to note.

Scott