NAME

prestotool − graphically display a machine’s Prestoserve state and statistics

SYNOPSIS

prestotool [ hostname ]

DESCRIPTION

Prestotool is a SunView window program that graphically displays a machine’s Prestoserve state and statistics.  The machine’s name is specified by hostname. If no name is specified, hostname is defaulted to “localhost”. 

A Prestoserve driver improves performance of accelerated  filesystems by reducing disk I/O through the caching of synchronous disk write operations.  Prestotool allows a user to visually inspect Prestoserve board state and Prestoserve driver statistics from any SunView terminal. 

The first line of the tool is dedicated to error and status messages.  This line is usually blank. 

The tool gets its information via remote procedure calls to the specified host.  The polling time may be controlled by the Sample time slider; the units are seconds.  The host being monitored may be changed by editing the host’s name and left mouse clicking the Host field. 

The third line displays the Prestoserve board state in three fields.  The first field, Size displays how much memory is utilized in the Prestoserve cache, e.g., “1M bytes”.  The second field, Board displays whether the board is enabled or not, e.g., “On” or “Off”.  Some machines may allow the users to toggle the state of their Prestoserve boards; this is done by left mouse clicking the Board field.  The third field displays the status of each of the Prestoserve board’s batteries by drawing either good battery icons or broken battery icons. 

On the fourth line, the Writes Pending slider shows the number of dirty buffers in the Prestoserve cache. 

The fifth line is blank and it serves to separate Prestoserve board state from Prestoserve driver statistics.  The display of Prestoserve driver statistics is controlled by the selection on the sixth line.  Epoch shows the statistics since the driver was last turned “On”.  This usually happens only when the machine is booted.  Cumulative shows the statistics accumulated from the time this option was selected.  Instantaneous shows the statistics since the last sample was taken. 

The last two lines show write and read statistics.  The Writes field shows the number of write requests that UNIX made to the Prestoserve driver.  The associated Percent Hits slider displays the percentage of those writes that overwrote a cached block in the Prestoserve cache.  (The percentage is computed from the sum of both clean hits and dirty hits.)  The write hit rate can be interpreted as the number of physical disk writes that were eliminated by the Prestoserve cache.  Similarly, the Reads field shows the number of read requests that UNIX made to the Prestoserve driver.  The associated Percent Hits slider displays the percentage of those reads that were performed by copying blocks out of the Prestoserve cache instead of doing physical disk reads. 

SEE ALSO

presto(1), presto(4), prestoctl_svc(8)

Prestoserve 1.1  —  Last change: September 13, 1989