[squid-users] cache.log

I'm getting some of these errors and see these in the archives:
--------------------------
> storeAufsOpenDone: (2) No such file or directory

A few of these is no reason to worry, and Squid should recover
automatically by forgetting it had the object cached, and process the
request as a cache miss.

If you get a lot of them, or if you repeatedly get such errors for the
same file or directory then there is reason to worry.
--------------------------
> squidaio_queue_request: WARNING - Queue congestion

if you only get this occationally then don't worry.

If you get a lot then your harddrive probably can not keep up with the
request rate you are having.
--------------------------

I guess I'm looking for ideas on what "few", "a lot" and "occasionally"
mean as we're getting the storeAufsOpenDone: error daily every few hours
it seems. The last couple of days the Queue congestion has happens in
the middle of these other messages a couple of times.

RH 7.3 (2.4.20-18.7)
Squid 2.5.STABLE2
1.6GHz Pent4 512MB
1 HD with 2GB cache on ReiserFS partition

Is this indicating a problem?