I've seen similar issues with AutoGrowth on the data and log files. When SQL Server needs to allocate more space, it stops all activity in the database until its completed. If you have your AutoGrow numbers at the default of 10%, back those down to something in the MB range.

-Mike

>Hello,
>
>I have SQL Server 2000 running on NT4. Periodically -- sometimes several times a day -- users can't connect to the server for maybe 30 minutes at a time. Nor can I connect through Enterprise Manager or Profiler from the server during that time. And when SQL Server is locked up, I can hear the HDD grinding away. The task manager shows low and consistent CPU usage.
>
>At other times performance seems just fine for the 10-15 concurrent users doing fairly basic, light stuff.
>
>The server is a Proliant 3000 with 1/2GB of RAM. Nothing else is running on the server except Agent, for which nothing is scheduled during these periods.
>
>I can't find anything in the logs which indicate any activity during these periods. Unfortunatly, Profiler can't connect either, so I can't trace what's going on.
>
>Anyone have any suggestions on what to look at or tips on how to diagnose this problem?