From: chip Date: Sat, 26 Feb 2000 07:33:51 +0000 (+0000) Subject: Rename from nhfsstone.1. X-Git-Tag: nfs-utils-0-1-7~17 X-Git-Url: https://git.decadent.org.uk/gitweb/?p=nfs-utils.git;a=commitdiff_plain;h=0761d72c6e51caf06ab904ef3018dd1321acfee2 Rename from nhfsstone.1. --- diff --git a/utils/nhfsstone/nhfsstone.man b/utils/nhfsstone/nhfsstone.man new file mode 100644 index 0000000..e205b68 --- /dev/null +++ b/utils/nhfsstone/nhfsstone.man @@ -0,0 +1,381 @@ +.\" @(#)nhfsstone.man 1.13 89/10/05 Copyright (c) 1989, Legato Systems Inc +.\" See DISCLAIMER file for restrictions +.TH NHFSSTONE 1 "4 October 1989" +.SH NAME +nhfsstone \- Network File System benchmark program +.SH SYNOPSIS +.B nhfsstone +[ +.B \-v +] [[ +.B \-t secs +] | [ +.B -c calls +]] [ +.B \-l load +] [ +.B \-p nprocs +] [ +.B \-m mixfile +] [ +.B dir +]... +.SH DESCRIPTION +.B nhfsstone +(pronounced n\-f\-s\-stone, the "h" is silent) +is used on a +.SM NFS +client to generate an artificial load with a particular mix of +.SM NFS +operations. It reports the average response time of the server in +milliseconds per call and the load in calls per second. +The program adjusts its calling patterns based on the client's kernel +.SM NFS +statistics and the elapsed time. +Load can be generated over a given time or number of +.SM NFS +calls. +.LP +Because it uses the kernel +.SM NFS +statistics to monitor its progress, +.B nhfsstone +cannot be used to measure the performance of non\-NFS filesystems. +.LP +The +.B nhfsstone +program uses file and directory manipulation in an attempt to generate +particular +.SM NFS +operations in response to particular system calls. +To do this it uses several tricks +that are based on a knowledge of the implementation of the +.SM NFS +client side reference port. +For example, it uses long file names to circumvent the kernel name lookup +cache so that a +.BR stat (2) +system call generates an +.SM NFS +lookup operation. +.LP +The mix of +.SM NFS +operations can be set with a mix file, which is the output of the +.BR nfsstat (8C) +command (see the "\-m" option below). +The percentages taken from +the mix file are calculated based on the number of +.SM NFS +calls, not on the percentages printed by nfsstat. Operations with +0% in the mix will never get called by +.BR nhfsstone . +In a real server load mix, even though the percentage of call for +a particular +.SM NFS +operation may be zero, the number of calls is often nonzero. +.B Nhfsstone +makes the assumption that the number of calls to these 0 percent +operations will have an insignificant effect on server response. +.LP +Normally +.B nhfsstone +should be given a list of two or more test directories to use +(default is to use the current directory). +The test directories used should be located on different disks and +partitions on the server to realistically simulate typical server loads. +Each +.B nhfsstone +process looks for a directory +.B /testdir +(where is a number from 0 to +.B nprocs +\- 1). +If a process directory name already exists, +it is checked for the correct set of test files. +Otherwise the directory is created and populated. +.SH OPTIONS +.TP 12 +.B \-v +Verbose output. +.TP +.B \-t secs +Sets +.B calls +based on the given running time (in seconds) and the load. +.TP +.B \-c calls +Total number of +.SM NFS +calls to generate (default is 5000). +.TP +.B \-l load +Load to generate in +.SM NFS +calls per second (default is 30). +.TP +.B \-p nprocs +Number of load generating sub\-processes to fork (default is 7). +This can be used to maximize the amount of load a single machine can generate. +On a small client machine (slow CPU or small amount of memory) +fewer processes might be used to avoid swapping. +.TP +.B \-m mixfile +Mix of +.SM NFS +operations to generate. +The format of +.B mixfile +is the same as the output of the +.BR nfsstat (8C) +program. +A mix file can be created on a server by typing "nfsstat \-s > mixfile". +The default mix of operations is: null 0%, getattr 13%, setattr 1%, +root 0%, lookup 34%, readlink 8%, read 22%, wrcache 0%, write 15%, create 2%, +remove 1%, rename 0%, link 0%, symlink 0%, mkdir 0%, rmdir 0%, readdir 3%, +fsstat 1%. +.SH USING NHFSSTONE +As with all benchmarks, +.B nhfsstone +can only provide numbers that are useful if experiments that use it are +set up carefully. +Since it is measuring servers, it should be run on a client +that will not limit the generation of +.SM NFS +requests. +This means it should have a fast CPU, +a good ethernet interface and the machine +should not be used for anything else during testing. +A Sun\-3/50 can generate about 60 +.SM NFS +calls per second before it runs out of CPU. +.LP +.B Nhfsstone +assumes that all +.SM NFS +calls generated on the client are going to a single server, and that +all of the +.SM NFS +load on that server is due to this client. +To make this assumption hold, +both the client and server should be as quiescent as possible during tests. +.LP +If the network is heavily utilized the delays due to collisions +may hide any changes in server performance. +High error rates on either the client or server can also +cause delays due to retransmissions of lost or damaged packets. +.BR netstat (8C) +.B \-i +can be used to measure the error and collision rates on the client and server. +.LP +To best simulate the effects of +.SM NFS +clients on the server, the test +directories should be set up so that they are on at least two of the +disk partitions that the server exports and the partitions should be +as far apart as possible. The +.BR dkinfo (8) +command can be used to find the physical geometry of disk on BSD based systems. +.SM NFS +operations tend to randomize +access the whole disk so putting all of the +.B nhfsstone +test directories on a single partition or on +two partitions that are close together will not show realistic results. +.LP +On all tests it is a good idea to run the tests repeatedly and compare results. +The number of calls can be increased +(with the +.B \-c +option) until the variance in milliseconds per call is acceptably small. +If increasing the number of calls does not help there may be something +wrong with the experimental setup. +One common problem is too much memory on the client +test machine. With too much memory, +.B nhfsstone +is not able to defeat the client caches and the +.SM NFS +operations do not end up going to the server at all. If you suspect that +there is a caching problem you can use the +.B -p +option to increase the number of processes. +.LP +The numbers generated by +.B nhfsstone +are most useful for comparison if the test setup on the client machine +is the same between different server configurations. +Changing +.B nhfsstone +parameters between runs will produce numbers that can not be +meaningfully compared. +For example, changing the number of generator processes +may affect the measured response +time due to context switching or other delays on the client machine, while +changing the mix of +.SM NFS +operations will change the whole nature of the experiment. +Other changes to the client configuration may also effect the comparability +of results. +While +.B nhfsstone +tries to compensate for differences in client configurations +by sampling the actual +.SM NFS +statistics and adjusting both the load and mix of operations, some changes +are not reflected in either the load or the mix. For example, installing +a faster CPU or mounting different +.SM NFS +filesystems may effect the response time without changing either the +load or the mix. +.LP +To do a comparison of different server configurations, first set up the +client test directories and do +.B nhfsstone +runs at different loads to be sure that the variability is +reasonably low. Second, run +.B nhfsstone +at different loads of interest and +save the results. Third, change the server configuration (for example, +add more memory, replace a disk controller, etc.). Finally, run the same +.B nhfsstone +loads again and compare the results. +.SH SEE ALSO +.LP +The +.B nhfsstone.c +source file has comments that describe in detail the operation of +of the program. +.SH ERROR MESSAGES +.TP +.B "illegal calls value" +The +.B calls +argument following the +.B \-c +flag on the command line is not a positive number. +.TP +.B "illegal load value" +The +.B load +argument following the +.B \-l +flag on the command line is not a positive number. +.TP +.B "illegal time value" +The +.B time +argument following the +.B \-t +flag on the command line is not a positive number. +.TP +.B "bad mix file" +The +.B mixfile +file argument following the +.B \-m +flag on the command line could not be accessed. +.TP +.B "can't find current directory" +The parent process couldn't find the pathname of the current directory. +This usually indicates a permission problem. +.TP +.B "can't fork" +The parent couldn't fork the child processes. This usually results from +lack of resources, such as memory or swap space. +.TP +.PD 0 +.B "can't open log file" +.TP +.B "can't stat log" +.TP +.B "can't truncate log" +.TP +.B "can't write sync file" +.TP +.B "can't write log" +.TP +.B "can't read log" +.PD +A problem occurred during the creation, truncation, reading or writing of the +synchronization log file. The parent process creates the +log file in /tmp and uses it to synchronize and communicate with its children. +.TP +.PD 0 +.B "can't open test directory" +.TP +.B "can't create test directory" +.TP +.B "can't cd to test directory" +.TP +.B "wrong permissions on test dir" +.TP +.B "can't stat testfile" +.TP +.B "wrong permissions on testfile" +.TP +.B "can't create rename file" +.TP +.B "can't create subdir" +.PD +A child process had problems creating or checking the contents of its +test directory. This is usually due to a permission problem (for example +the test directory was created by a different user) or a full filesystem. +.TP +.PD 0 +.B "bad mix format: unexpected EOF after 'nfs:'" +.TP +.B "bad mix format: can't find 'calls' value" +.TP +.B "bad mix format: unexpected EOF after 'calls'" +.TP +.B "bad mix format: can't find %d op values" +.TP +.B "bad mix format: unexpected EOF" +.PD +A problem occurred while parsing the +.B mix +file. The expected format of the file is the same as the output of +the +.BR nfsstat (8C) +command when run with the "\-s" option. +.TP +.B "op failed: " +One of the internal pseudo\-NFS operations failed. The name of the operation, +e.g. read, write, lookup, will be printed along with an indication of the +nature of the failure. +.TP +.B "select failed" +The select system call returned an unexpected error. +.SH BUGS +.LP +Running +.B nhfsstone +on a non\-NFS filesystem can cause the program to run forever because it +uses the kernel NFS statistics to determine when enough calls have been made. +.LP +.B Nhfsstone +uses many file descriptors. The kernel on the client may +have to be reconfigured to increase the number of available file table entries. +.LP +Shell scripts that used +.B nhfsstone +will have to catch and ignore SIGUSR1 (see +.BR signal (3)). +This signal is +used to synchronize the test processes. If the signal is not caught +the shell that is running the script will be killed. +.SH FILES +.PD 0 +.TP 20 +.B /vmunix +system namelist +.TP +.B /dev/kmem +kernel virtual memory +.TP +.B ./testdir* +per process test directory +.TP +.B /tmp/nhfsstone%d +process synchronization log file +.PD