you should collect disk usage data to keep apprised of any changes that might be necessary.
The system might expand to more users (and thus more transactions),
the requirement for the database might change (resulting in a larger database size), and so on.
When performing post-capacity planning studies on disk usage,
you should track the following counters in Performance Monitor.
These counters can be found in the [PhysicalDisk] object:
* % Disk Time
Percentage of elapsed time that the selected disk drive is busy servicing read or write requests.
* % Disk Read Time
Percentage of elapsed time that the selected disk drive is busy servicing read requests.
* % Disk Write Time
Percentage of elapsed time that the selected disk drive is busy servicing write requests.
* Avg. Disk Read Queue Length
Average number of read requests that were queued for the selected disk during the sample interval.
* Avg. Disk Write Queue Length
Average number of write requests that were queued for the selected disk during the sample interval.
* Avg. Disk Queue Length
Average number of both read and write requests
that were queued for the selected disk during the sample interval.
It is the sum of the previous two items.
* Disk I/O Count Per Second
I/O activity to the disk array per second averaged over the measurement period.
This counter is not directly available through Performance Monitor;
to arrive at this value, you simply add together the values of two other counters
that are available—Disk Reads/sec and Disk Writes/sec.
* Disk Space Used
Amount of disk space currently being used by either the database or the operating system. This counter is not available through Performance Monitor;
use the Disk Administrator to access this information.
* Disk Space Available
Amount of disk space currently available.
This counter is not available through Performance Monitor;
use the Disk Administrator to access this information.
To start the Disk Administrator,
click Start, and then choose Programs, Administrative Tools (Common), and finally Disk Administrator.
Source:
Microsoft SQL Server 2000 Administrator's Companion eBook