[OpenAFS] AFS Speed

[Jimmy Engelbrecht]

Nathan Ward <nward@esphion.com> writes:

> I have an AFS cell, which has a single fileserver and a bunch of
> workstations.
> 
> The fileserver has ~180Gb of storage, which achieves ~60Mb/sec when
> writing directly to an ext2 partition.
> 
>  From all my client machines, the access speeds to the AFS server are
> shocking. Deleting a tree that is ~25Mb of source files (ie smallish
> files) takes upward of 30 minutes, and there appears to be very little
> CPU load on the server and client machines during this time...
> 
> Reading that tree takes a long time (I dont have any figures right
> now), but not as long as writing or deleting.
> 
> It seems that all the fileserver processes are at about 0.1-0.9% CPU,
> and are almost always sleeping.
> 
> Network speed is not an issue, as there is full gigE between the 2 machines.
> 
> I originally attributed this to the fact that AFS has its own
> databases etc and manipulating them could be slowing it down, but if
> that were the case, you'd think that the CPU load on the server would
> be much higher.
> 
> There is around about 2500-4000 contexts switches per second, im not
> sure if thats a high value or not.

run afsfsperf from the arla-0.36-branch and compare it with my numbers.

http://www.e.kth.se/~jimmy/afsfsperf/afsfsperf.html

/Jimmy