dxpresto(8)
Name
dxpresto − graphically display Prestoserve state and statistics
Syntax
/usr/etc/dxpresto [ hostname ]
/usr/etc/dxpresto hostname options
Description
The dxpresto command is an X Window System application that graphically displays a machine’s Prestoserve state and statistics. The dxpresto command uses a Remote Procedure Call (RPC) protocol to communicate with the machine being monitored. You use the dxpresto command to provide general information about Prestoserve and to help manage Prestoserve. Also, you can use the command to demonstrate the efficacy of the Prestoserve software.
Use the hostname variable to specify the machine that you want to monitor; the machine must be running the Prestoserve software. If hostname is not specified and options are not specified, then localhost, an alias for the local machine that is running the Prestoserve software, is used. You must specify hostname if you want to use options.
Note
The machine that you want to monitor must be running the prestoctl_svc daemon. Also, if you want to be able to enable or disable Prestoserve on the machine, it must be running the prestoctl_svc daemon with the −n option.
Because dxpresto is an X Window System application, your DISPLAY environmental variable must be set to a machine that is an X Server. For more information, see X(.).
The dxpresto window shows the following information:
•The Host field shows the name of the host that you are monitoring. You can type another host name in the field and hit the RETURN key to monitor that host.
•The Presto State buttons show the Prestoserve state, either Enabled (UP), Disabled (DOWN), or Error (ERROR). If the machine being monitored is running the prestoctl_svc daemon with the −n option, you can change the machine’s Prestoserve state to either Enabled (UP) or Disabled (DOWN) by clicking on the appropriate button. You cannot click on the Error button; contact the server administrator or the server hardware Field Service representative if the Error button is enabled.
•The Sample Interval slider shows the interval of time between Prestoserve queries, and it allows you to change that interval. When you invoke the dxpresto command, the default Sample Interval is 5; therefore Prestoserve information is gathered every five seconds. For example, if you want Prestoserve queried more often, move the slider to the left and click on MB1 until 2 appears; Prestoserve is then queried every two seconds.
•The Time since last Enable field shows the time since Prestoserve was last enabled. The time is displayed in hours, minutes, and seconds. The total number of seconds is also shown.
•The Size field displays the number of Kbytes of nonvolatile memory that the Prestoserve cache is utilizing. Note that Prestoserve can utilize less than the default maximum size of its Prestoserve cache if you changed the cache size with the presto −s command.
•The Batteries graphics show the state of the Prestoserve backup battery system. An intact battery icon with the word ok indicates that the battery has sufficient power. An intact battery icon with the word low indicates that the battery’s power is low. A broken battery icon indicates that the battery is disabled. Prestoserve goes into the ERROR state when the backup battery power falls below a minimum amount. Contact the server administrator or the server hardware Field Service representative if a battery is low or disabled.
•The Display Cache Utilization buttons allow you to display or to not display graphs that demonstrate how the Prestoserve cache is being utilized.
•The Display Cache Statistics buttons allow you to display or to not display the Prestoserve cache statistics table.
•The Exit button allows you to exit from dxpresto.
•The error bar displays error messages for both Prestoserve and the dxpresto command. For example, if the prestoctl_svc daemon with the −n option is not running on the machine you are monitoring, then a message is displayed indicating that changes to Prestoserve operation are not allowed.
Some error messages, such as those indicating RPC communication failure, are displayed on the terminal from which you invoked the dxpresto command.
If you display the Display Cache Utilization graphs, the following is shown:
•The Presto buffers bar graph shows how the Prestoserve cache operations are distributed among the four Prestoserve buffer states: dirty, clean, inval, and active. The vertical axis shows the maximum number of objects or disk blocks that the entire Prestoserve cache can contain. The sum of the four bars is the total number of buffers used in the Prestoserve cache. Note that the size of the Prestoserve cache can be changed by using the presto −s command.
•The Writes per second trend line graph shows a recent history of the average number of writes per second over the time intervals that are determined by the Sample Interval slider.
Each point in the horizontal axis represents a sample time interval as determined by the Sample Interval slider; the maximum number of samples that can be shown is 210. When you reach the maximum number of samples, the graph shifts to the left so you can see at least the last 105 samples, which is half the maximum number of samples. If you choose 5 in the Sample Interval slider, Prestoserve is queried every five seconds; therefore it takes 1050 (5 x 210) seconds to obtain the maximum of 210 samples.
The vertical axis shows the average number of writes performed per second within the sample time interval as determined by the Sample Interval slider.
For example, if you choose 2 in the Sample Interval slider, Prestoserve is queried every two seconds, and each point in the graph shows the average number of writes performed within the interval of two seconds. If the graph shows that an average of 5 writes per second were performed within two seconds, Prestoserve actually performed 10 writes within those two seconds. The calculation is:
5 writes
---------- x 2 sec = 10 writes
sec
If you change hosts, the Writes per second graph displays a vertical line of dashes to distinguish the new host’s information from the previous host’s information.
•The Hits per second trend line graph shows a recent history of the average number of Prestoserve cache hits per second over the time intervals that are determined by the Sample Interval slider. The Prestoserve cache hits represent the total number of clean and dirty read and write hits (blocks that match blocks already in the cache).
Each point in the horizontal axis represents a sample time interval as determined by the Sample Interval slider; the maximum number of samples that can be shown is 210. When you reach the maximum number of samples, the graph shifts to the left so you can see at least the last 105 samples, which is half the maximum number of samples. If you choose 2 in the Sample Interval slider, Prestoserve is queried every two seconds; therefore it takes 420 (2 x 210) seconds to obtain the maximum of 210 samples.
The vertical axis shows the average number of hits performed per second within the sample time interval as determined by the Sample Interval slider.
For example, if you choose 10 in the Sample Interval slider, Prestoserve is queried every 10 seconds, and each point in the graph shows the average number of hits performed within the interval of 10 seconds. If the graph shows that an average of 2 hits per second were performed within 10 seconds, Prestoserve actually performed 20 writes within those 10 seconds. The calculation is:
2 hits
---------- x 10 sec = 20 hits
sec
If you change hosts, the Hits per second graph displays a vertical line of dashes to distinguish the new host’s information from the previous host’s information.
If you display the Display Cache Statistics table, the following is shown:
•The Prestoserve statistics table is similar to the information that is displayed when you use the presto −p command. For each Prestoserve cache read or write operation, Prestoserve increments an appropriate counter. The table shows:
The clean hits counter, which is the number of hits on the clean buffers
The dirty hits counter, which is the number of hits on the dirty buffers (each dirty hit represents a physical disk write that was avoided entirely)
The passes counter, which is the number of I/O operations that Prestoserve passed directly to the actual device driver
The count, which is the sum of the three previous counters
The hit rate percentage, which is the ratio of clean hits and dirty hits to the total count
•The Since last Enable button allows you to display Prestoserve statistics since Prestoserve was last enabled. This is useful when you want to determine how Prestoserve performs over a long period of time.
•The Since last Sample button allows you to display the Prestoserve statistics for each sample time interval as determined by the Sample Interval slider. If no Prestoserve activity occurs during the time interval, the numbers in the statistics table are zero. For example, if the Sample Interval slider is set to 5 and the Since last Sample button is enabled, the statistics table shows the Prestoserve statistics for each interval of five seconds.
•The Since last Zero button allows you to display Prestoserve statistics since you clicked on the Zero button. This button allows you to determine how Prestoserve performs over a specific period of time that you can set by using the Zero button.
•The Zero button allows you to set a time reference for the Prestoserve statistics table. If you click on the Zero button and, at a later time, click on the Since last Zero button, the table displays the Prestoserve statistics since you clicked on the Zero button.
Options
−bd color Specifies the color of the window’s border (color displays only). The default is black.
−bg color Specifies the color of the window’s background (color displays only). The default is white.
−d dispname Specifies the display screen on which dxpresto displays its window. If the display option is not specified, dxpresto uses the display screen specified by your DISPLAY environment variable. The display option has the format hostname:number. Using two colons (::) instead of one (:) indicates that DECnet is to be used for transport. The default is :0. For more information, see X(.).
−display dispname This option is the same as the −d option.
−fg color Specifies the color of the text (color displays only). The default is black.
−geometry Specifies the width, length, and location of the dxpresto window. If the geometry option is not specified, dxpresto uses default values. The geometry option has the format =[width][xlength][x][y]. For more information about the screen coordinate system, see X(.).
X Defaults
The dxpresto application uses the values in the .Xdefaults file when you logged in and uses the appropriate resource specification to customize the appearance or characteristics of its displayed dxpresto window. The format for a resource specification in the .Xdefaults file is:
[name*]resource: value
nameSpecifies the application name or the name string that restricts the resource assignment to that application or to a component of an application. If this argument is not specified, the resource assignment is globally available to all X applications.
resourceSpecifies the resource.
valueSpecifies the value that is to be assigned to the resource.
For more information, see X(.).
Because each toolkit-based application can consist of a combination of widgets (for example, push buttons and a scroll bar), you can form the name string by adding widget class and name identifiers to the string. For further information about adding class and name identifiers, see X(.).
For dxpresto, the available name identifiers are:
graph_parentThe dialog box containing all of the graphs
dirty_graphThe graph displaying dirty buffers
clean_graphThe graph displaying clean buffers
inval_graphThe graph displaying inval buffers
active_graphThe graph displaying active buffers
write_graphThe graph displaying cache write history
hit_graphThe graph displaying cache hit history
Examples
If you want to change the foreground and background colors of the dxpresto window and to customize the window’s graphs, you can add the following entries to your .Xdefaults file:
dxpresto*background: darkslategray
dxpresto*foreground: wheat
dxpresto*borderColor: gold
dxpresto*highlight: yellow
dxpresto*graph_parent*borderColor: firebrick
dxpresto*dirty_graph*highlight: gold
dxpresto*dirty_graph*background: black
dxpresto*clean_graph*highlight: gold
dxpresto*clean_graph*background: black
dxpresto*inval_graph*highlight: gold
dxpresto*inval_graph*background: black
dxpresto*active_graph*highlight: gold
dxpresto*active_graph*background: black
dxpresto*write_graph*highlight: gold
dxpresto*write_graph*background: black
dxpresto*hit_graph*highlight: gold
dxpresto*hit_graph*background: black
Files
/usr/lib/X11/uid/dxpresto.uid
~/.Xdefaults
See Also
presto(4), presto(8), prestoctl_svc(8), X(1X)
Guide to Prestoserve