tapex.8

<B>Digital的Unix操作系统VAX 4.2源码</B>

.TH tapex 8
.SH Name
tapex \- tape exerciser program
.SH Syntax
.B tapex
[
.I option(s)
]
[
.I parameter(s)
]
.SH Description
The
.PN tapex
program tests tape driver functionality.
.NXR "tapex program"
These tests provide more comprehensive functional coverage than the
.PN mtx
utility which does simple start/stop oriented read/write testing.
Functions that are tested include:
.RS 3
.IP \(bu 4 
Writing records onto a tape and verifying the records
.IP \(bu  
Using records in a range of sizes
.IP \(bu  
Record-length testing
.IP \(bu 
Random record-size testing
.IP \(bu 
Positioning tests for records and files
.IP \(bu 
Writing and reading past the end of media
.IP \(bu 
End-of-file testing
.IP \(bu 
n-buffered I/O testing
.IP \(bu 
Tape-transportability testing
.IP \(bu 
Bandwidth performance analysis
.IP \(bu 
Media loader testing
.IP \(bu 
Reporting of tape contents
.RE
.PP
When 
.PN tapex
is run, a writable tape must be loaded in the drive being 
tested, and the drive must be online.

.SH Options
Some
.PN tapex
options cause specific tests to be performed, for example, an 
end-of-media test.  Other options modify the tests, 
for example, enabling caching.  The 
.PN tapex 
options are as follows:
.NXR "tapex program" "options"
.IP \-a 5
Performance measurement test that calculates the tape transfer bandwidth
for writes and reads to the tape by timing data transfers.
.IP \-b 5
Continuously runs the write/read tests until the process is killed.
This flag can be used in conjunction with the 
.PN \-r
or 
.PN \-g 
flag.
.IP \-c 5
Enables caching on the device, where supported.  This does not
specifically test caching, but it enables the use of caching on
a tape device while running the other tests.
.IP \-C 5
Disables caching on TMSCP tape devices.  If the tape device is
a TMSCP unit, then caching is the default mode of test operation.
This flag causes the tests to be run in noncaching mode.
.IP \-d 5
Tests the ability to append to the media.  First, the test
writes records to the tape.  Then, it repositions back one
record and appends additional records. Finally, the test does a 
read verification. This test simulates the behavior
of the 
.PN "tar r"
switch.
.IP \-e 5
End-of-media test.  This test first writes
data to fill up a tape, which may take a long time for long tapes.
It then does reads and writes past the end of media, 
which should fail.  
Next it enables writing past end of media, writes to the tape, and reads
back the records for validation.
.IP \-E 5
Runs an extensive series of tests in sequential order.  
Due to the large number of tests, this option takes a long 
time to complete.  Depending on tape 
type and cpu type, this series of tests can take up to 
10 hours to complete.
.IP "\-f \f(CW/dev/rmt#\fI?\FP" 5
Specifies the name of the device special file that 
corresponds to the tape unit being tested.
The number sign (#) symbol represents the unit number. 
The question mark (?) argument can be the
letter 
.PN h 
for the high density device or the letter
.PN l 
for the low density device.  The default tape device is 
.PN /dev/rmt0h .
.IP \-F 5
File-positioning tests.  First, files are written to the tape and
verified.  Next, every other file on the tape is read. Then, the
previously unread files are read by traversing the tape backwards.  
Finally, random numbers are generated; the tape is positioned to those
locations, and the data is verified.  Each file uses a
different record size.
.IP \-G 5
File-positioning tests on already-written tape.  This flag
can be used in conjunction with the 
.PN \-F 
flag to run the file position tests on a tape that has already been
written to by a previous version of the 
.PN \-F 
test.  For this to work, the same test parameters,
for example record size and number of files, must be used as when the
the tape was written.  No other data should have been written to
the tape since the previous 
.PN \-F 
test.
.IP \-g 5
Random record-size tests.  This test writes records of random sizes.
It reads in the tape, specifying a large read size; however, only
the amount of data in the randomly-sized record should be returned.
This test only checks return values and does not validate record
contents.
.IP \-h 5
Displays a help message describing the tape exerciser.
.IP \-i 5
Interactive mode. Under this mode, the user is prompted
for various test parameters.  Typical parameters include the record
size and the number of records to write.
The following scaling factors are allowed:
.RS
.IP "k \fRor\fP K" 10
for kilobyte (1024 * n)
.IP "b \fRor\fP B" 10
for block (512 * n)
.IP "m \fRor\fP M" 10
for megabyte (1024 * 1024 * n)
.RE
.PP
For example, 10k would specify 10240 bytes.
.IP \-j 5
Write phase of the tape-transportability tests.  This test writes
a number of files to the tape, and then verifies the tape.  After
a successful verification, the tape is brought offline to be
moved to another tape unit and read in with the 
.PN \-k
option.
The purpose of this test is to prove that a tape can be written
on one drive and read by another drive.  Note that the test
parameters for the 
.PN \-k 
phase of the transportability test must
match the parameters of the 
.PN \-j 
test.  Any changes of test parameters from the defaults should 
also be changed during the 
.PN \-k 
test.
.IP \-k 5
Read phase of the tape-transportability tests.  This test reads
a tape that was written by the 
.PN \-j 
test and verifies that the expected
data is read from the tape.  Success of this test proves that a tape
can be written on one drive and read on another.  As
stated in the the description of the 
.PN \-j 
option, any parameters changed in the 
.PN \-j 
test must also be changed in the 
.PN \-k 
test.
.IP \-L 5
Media loader test.  For sequential
stack loaders, the media is loaded, written to, and verified.  Then 
the media is unloaded, and the test repeats on the next piece of
media.  This verifies that all the media in the input deck 
is writable.  To run this test in read-only mode, also specify the 
.PN \-w 
option.
.IP \-l 5
End-of-file test. This test verifies that a zero byte count is
returned when a tape mark is read and that another read will
fetch the first record of the next tape file.
.IP \-m 5
Displays tape contents. This is not a test; it reads the tape
sequentially and prints out 
the number of files on the tape, the number of
records in each file, and the size of the records within the file.  The
contents of the tape records are not examined. 
.IP \-N 5
Disables the usage of n-buffered I/O on tests that support its usage.
(See 
.MS nbuf 4
for a description of n-buffered I/O.)
.IP "\-o \fIfilename\fP" 5
.br
Sends output to the specified filename.  The default is to not create an
output file and send output to the terminal. 
.IP \-p 5
Runs both the record and file positioning tests. (See the 
.PN \-R 
and 
.PN \-F 
options.)
.IP \-q 5
Command timeout test.  This test verifies that the driver
allows enough time for completion of long operations.  The test
consists of writing files to fill up the tape.  Next a rewind is
performed followed by a forward skip out to the last file.  The
test is successful if the forward skip operation completes without
error.
.IP \-r 5
Record-size test.
A number of records are written to the tape and then verified.
This process is repeated over a range of record sizes.
.IP \-R 5
Record-positioning test.  First, records are written to the tape and
verified.  Next, every other record on the tape is read. Then, the
other records are read by traversing the tape backwards.  Finally,
random numbers are generated; the tape is positioned to those
locations, and the data is verified.
.IP \-s 5
Record-size behavior test.  Verifies that a record read will return
at most one record or the read size, whichever is less.
.IP \-S 5
Single record size test.  This option modifies the record-size test (
.PN \-r 
option).
.IP \-T 5
Copies output to standard output.  This flag is useful if
you want to log output to a file with the 
.PN \-o 
option and also have the output displayed on standard output.  
This flag must be specified after the 
.PN \-o 
flag in the command line.
.IP \-v 5
Verbose mode.  This option causes more detailed terminal output of
what the tape exerciser is doing.  For example, it lists
operations the exerciser is performing, such as record counts,
and more detailed error information.
.IP \-V 5
Very verbose mode.  This option causes more output to be
generated than either the default mode or the 
.PN \-v 
flag.  The output consists of additional status information on exerciser
operation. 
.IP \-w 5
Opens the tape as read-only.  This mode is only useful for tests
that do not write to the media.  For example, it allows the 
.PN \-m 
test to be run on a write-protected media.
.IP \-Z 5
Initializes read buffer to the nonzero value 0130.
This may be useful for debugging purposes.  If the 
.PN \-Z 
flag is not specified, all elements of the read 
buffer will be initialized to 0. Many of the tests first 
initialize their read buffer and then perform
the read operation.  After reading a record from the tape, some tests
validate that the unused portions of the read buffer 
remain at the value to which they were initialized.  
As a debugging tool, it may in some cases be
useful to have this initialized value set to be nonzero. In those cases,
the arbitrary character 0130 can be used. 
.SH Parameters
.NXR "tapex program" "parameters"
You can change the default test parameters either by using the 
.PN \-i 
option described previously or by specifying the parameters in the command
line. This section describes the parameters you can set in the command
line, listed with the associated test. 
.PP
To specify a value, type the parameter name followed by a space
and then the number.  For example 
.PN \-min_rs 
512 specifies a minimum record size of 512 blocks.
The following scaling factors are allowed:
.RS 5
.IP "k \fRor\fP K" 10
for kilobyte (1024 * n)
.IP "b \fRor\fP B" 10
for block (512 * n)
.IP "m \fRor\fP M" 10
for megabyte (1024 * 1024 * n)
.RE
.PP
For example, 10K would specify 10240 bytes.

These parameters are associated with the option 
.PN \-a :
.IP \-perf_num 10
The number of records to write and read.
.IP \-perf_rs 10
The size of records.

.PP
These parameters are associated with the option 
.PN \-d :
.IP \-tar_num 10
The number of additional and appended records.
.IP \-tar_size 10
The record size for all records written in this test.

.PP
These parameters are associated with the option 
.PN \-e .
.PP
Note that specifying too much data to be written past EOM could cause
a reel-to-reel tape to go off the end.
.IP \-end_num 10
The number or records written past EOM.
.IP \-end_rs 10
The record size.

.PP
These parameters are associated with the option 
.PN \-F :
.IP \-num_fi 10
The number of files.
.IP \-pos_ra 10
The number of random repositions.
.IP \-pos_rs 10
The record size.
.IP \-rec_fi 10
The number of records per file.
.PP
This parameter is associated with the option
.PN \-g :
.IP \-rand_num 12
The number of records to write and read.
.PP
These parameters are associated with the options 
.PN \-j 
and 
.PN \-k :
.IP \-tran_file 10
The number of files to write or read.
.IP \-tran_rec 10
The number of records contained in each file.
.IP \-tran_rs 10
The size of each record.
.PP
These parameters are associated with the option 
.PN \-R :
.IP \-pos_num 10
The number of records.
.IP \-pos_ra 10
The number of random repositions.
.IP \-pos_rs 10
The record size.
.PP
These parameters are associated with the options 
.PN \-r 
and 
.PN \-S :
.IP \-inc 10
The record increment factor.
.IP \-max_rs 10
The maximum record size.
.IP \-min_rs 10
The minimum record size.
.IP \-num_rec 10
The number of records.
.IP \-t 10
Sets a time limit in minutes on how long to run the record-size test (
.PN \-r
option).  The default is to run the test to completion.
.PP
These parameters are associated with the option 
.PN \-s :
.IP \-num_rec 10
The number of records.
.IP \-size_rec 10
The record size.
.PP
This parameter is used in any test which supports n-buffered I/O:
.IP \-num_nbuf 12
The number of buffers to use.
.PP
This parameter is associated with all tests:
.IP \-err_lines 10
The threshold on error printouts.
.SH Examples
This example runs a series of tests on tape device 
.PN rmt1h 
and sends all output to a file called 
.PN tapex.out .
.EX
tapex \-f /dev/rmt1h \-E \-o tapex.out
.EE
This example runs the end-of-media test on tape device 
.PN rmt4h .  
Verbose mode is specified, which causes additional output.  
By default, output is directed to the terminal.
.EX
tapex \-f /dev/rmt4h \-v \-e
.EE
This example performs read/write record testing. 
By default, this test runs on the default tape device 
.PN /dev/rmt0h 
and output is sent to the terminal. 
.EX
tapex \-r
.EE
This example performs read/write record testing 
using record sizes in the range 10k to a maximum record size of 20k.  
By default, this test runs on the default tape device 
.PN /dev/rmt0h 
and output is sent to the terminal.
.EX
tapex \-r \-min_rs 10k \-max_rs 20k
.EE
.SH See Also
mtx(8)
.br
.I "Guide to System Exercisers"