The Files / Disk Entity LH screen presents the MEASURE entity DISC. Data is available live or via history.
The MEASURE entity DISC provides information about the overall disk volume. A mirrored drive would have four paths, Primary, Backup, Mirror and Mirror Backup. By default, MOMI combines these paths into a single line of information referred to as Volume View.
The Data Type field selects either Live (the default) or History. The Config button displays available options which are different depending on the Data Type selection.
Config for Live allows the selection of Volume view, if records with all zero values are displayed, and the screen update interval.
Config for History determines the starting date/time, selection of Volume view, history file where data is retrieved, if records with all zero values are displayed and filtering by Disk and/or CPU.
Clicking on a Disk Name displays Cache Detail showing all cache sizes and cache specific counts. The color bars, on lines with +%, represent percent of the total for that particular operation. Place the mouse over the cell and the tool-tip displays the underlying value.
Volume view
Volume view combines values from all four disk paths (P, B, M, MB) in an attempt to represent the overall activity on the logical disk drive. When Volume view is NOT selected, MEASURE data is displayed as is, with the exception of derived values.
Output bytes represents the bytes written to one disk volume of the mirrored set. For example, Input Bytes and Output Bytes would equal each other if 4096 bytes were written and immediately read (technically, 8192 bytes were written as the data is copied to each physical disk of the mirrored set).
Derived values
The following values are derived:
disc_rate
reads + writes
Cache Detail
MEASURE does not directly provide all the values displayed and the following values are derived (and may be changed as we learn more about how to obtain them):
cache_calls
hits
+ misses
cache_writes
cache_write_cleans
+ cache_write_dirties
+ cache_write_misses
cache_reads
cache_calls
- cache_writes
cache_read_hits
cache_reads
- misses