vdt - visual disk test
vdt [-options]
vdt performs i/o tests on files, logical volumes, partitions or whole disks.
vdt offers various disk addressing patterns and test area selections.
basic parameters:
-b size alternate i/o buffer size -c filename target for (read) comparison tests -e seed random number generator seed -f filename use this file for read/write tests -m number maximum number of iterations per test -p percent test area = given % of testsize -P pattern filler for output buffer (0oct|xhex|dec|rand|zero) -r filename input(source) for read-only(comparison) tests -s stripes split test area in given # of stripes -t seconds maximum elapsed time per test -w filename use this output file for write-only tests -z testsize test area = just this much (default=whole file)
basic tests:
--make create & fill test (Bunch_of_Sectors at a time) --poke poke test (same as '--writ --sect') --read read test (B.o.S. at a time) --seek seek test (same as '--read --sect') --writ write test (B.o.S. at a time)
compound tests:
--aver ratification test (write, read back, compare) --blot update test (read, stain, write back) --comp comparison test (B.o.S. at a time) --cool freshen test (read, write back) --copy copy test (B.o.S. at a time) --mess shuffle test (read, write somewhere else)
stress tests:
--burn burn (read/write) test (all addressing modes) --cook cook (read-only) test (all addressing modes)
address patterns:
--incr incrementing addresses (start to end) --decr decrementing addresses (end to start) --conv converging addresses (edges to middle) --scat scattering addresses (middle to edges) --gold 'diamond'-pattern (middle to edges and back) --spot 'X'-pattern (edges to middle and back) --rand random addresses
region selection:
--edge --head and --tail combined --head select initial portion of test area (default) --core select central portion of test area --tail select final portion of test area --slab --edge and --core combined --even divide test area proportionally --flip invert selection of test area
entropy control:
--same yields same random numbers across tests --firm yields same random numbers across platforms --fate same as '--same --firm' --whim extra entropy for unpredictable randomness
operation flags:
-A append to log file -E separate error messages into 'vdt.err' -T timestamped names for log and error files -V show version info and exit -v verbose and additional details
--si use powers of 1000 not 1024
--fast apply faster algotythms --full random seek within B.o.S. --help show this usage help --once same as --uniq --raze flatten (truncate) output file --sync synchronous (blocking) output --uniq test each and every random address just once --wait request user interaction to finish
extra parameters:
-L lines override screen's # of lines -C columns ditto for columns
Without any options, vdt shows a minimal help message, and bails out.
Upon completion, a log file (`vdt.log' by default) can be found in the calling directory.
The location and name of this log file can be modified by means of the flags shown above.
Any test can be time-limited by using the '-t seconds' option.
The '-v' flag enhances log details and improves visual feedback.
Ordinarily, Vdt does not interact with the observer, but the '--wait' flag can give you an option to pause at test completion just before cleaning up the screen (specially useful if tests are short-lived).
Vdt can be interrupted at any time with '^C' (Control+C).
vdt.log vdt's log file vdt.err separate error messages vdt.opt vdt's options file
$HOME/.vdt vdt's workplace (if found) /usr/local/bin vdt's default executable path
Example 1: create and fill a 64MiB new file
$ vdt -w test.dat --make -z 64M
Example 2: basic read test from start to end
$ vdt -r test.dat --read --incr
Example 3: basic write-test an existing file from start to end
$ vdt -w test.dat --writ --incr
Example 4: stress write-test an existing file
$ vdt -w test.dat --burn
Example 5: copy-test an existing file to a new one, pausing at completion.
$ vdt -r test.dat -w clone.dat --copy --wait
Example 6: compare-test two existing files, pausing at completion.
$ vdt -r test.dat -c clone.dat --comp --wait
Example 7: time-limited (to 3 seconds) random write-test with pause
$ vdt -w test.dat --writ --rand --wait -t 3
Example 8: same as above with synchronous/blocking output
$ vdt -w test.dat --writ --rand --wait -t 3 --sync
TERM The value of the TERM environment variable may affect
the output of `vdt'.
VDT Optionally used to automate initialization of flags
and/or parameters.
The following exit values are returned:
0 No errors of any kind.
>0 An error occurred.
EACCES Permission denied (POSIX.1)
Search permission is denied for
a component of the path prefix
of a given <pathname>.
ENOTTY Inappropriate I/O control operation (POSIX.1)
The type of the file or device being tested
is not suitable (eg. chosing a block device
instead of a raw device).
df(1), mount(1), iostat(1).
Ordinarily, `vdt' does not require `root' privileges or SUID file permissions in order to operate on regular files.
The INT, and TERM signals are caught by `vdt', allowing for an orderly quit.
The QUIT signal causes `vdt' to restart the current test, as would happen in the case of a window resize.
On some operating systems, the logical sector size may be greater than 512 bytes.
When the test subject is big enough while available memory not so, enlarging the screen window may avoid buffer allocation failures.
In the event of a failure to detect the actual disk/partition size, providing an explicit test area size (by means of '-z') may circumvent the problem.
On FreeBSD-7-x86 and Solaris-10-x86_64, using the default 24x80 screen leads to a miscalculation of available columns; the workaround is (if possible) to manually enlarge the screen window horizontally by at least one column, or to use the '-C 64' option in order to force the use of all available columns.
A screen with less than 24 lines results in garbled output.
Not all possibly harmfull/misleading combinations of flags are prevented.
The original and current versions of `vdt' consist of code and documentation written by:
Alexandre Botao http://botao.org
botao@unix.sh
botao@linux.sh alexandre@botao.org
Copyright 2010 Alexandre Botao
`vdt' is `Free and Open Source Software' (FOSS), and is licensed under the GNU GENERAL PUBLIC LICENSE Version 3 (the "License");
You may not use `vdt' except in compliance with the License. You may obtain a copy of the License at
http://www.gnu.org/licenses/
Additionally, a copy of the License is distributed along with `vdt' in a file called 'LICENSE';
Commercial support is NOT available for `vdt'. Suggestions and/or bug reports are very welcome.
`vdt' is distributed on an ``AS IS'' basis, WITHOUT ANY WARRANTY OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.