I see a chart labeled DB Writes in the ProTop Portal. What's it about?
Charts in the ProTop Portal typically include a left and right axis. Which axis applies to which metric can be seen in the legend in the top right of the chart.
In this case, the left axis shows "Logical write/sec". Logical writres are block update operations in the –B buffer cache.
OS Writes (right axis) occur when a block is written from the buffer cache to disk.
These metrics are ”per second”.