Test integrity of SD cards

The purpose of this application is to test the integrity of SD cards, and in particular to test that it is not reporting a fake card size.

There are other applications that will do the same task, some are destructive testing, and many can take days to complete the tests on a large card (this application can still take several hours to run, but should not take days).

This contains three programs

sdtest.rb

• sdtest.rb will create lots of files and tests they have been correctly written.
• If the program completes successfully it will delete the test files, although it will leave the directory /sd_test on the card, and this directory will have to be removed manually.
• If the program detects errors then all of the test files it has created will be left on the SD card lest you wish to look at the problems in more detail later. These files will nonetheless be removed the next time the program is run.
• The program is designed to be non-destructive, and so should not remove any files it has not itself created; but if the SD card is faulty it is possible that other files on the card may become corrupted by the actions of this program.

sdtest_check.rb

• sdtest_check.rb will read through the test files created by sdtest.rb when sdtest.rb has failed to remove the test files (e.g. when sdtest.rb detected failures during its run).

sdtest_extend.rb

• sdtest_extend.rb runs similar to sdtest.rb but unlike sdtest.rb it will not remove any previous test files it encounters. This allows the test to be stopped and restarted without having to recreate test files that were previously created.

Parameters

The only parameter that either program uses is the block device that SD card is mounted on (e.g. /dev/sdc1). The card must be mounted in order for the application to work, and it should either be completely empty or almost completely empty (the program will still run even if the card is almost full, but it will probably not return any useful information since there will be not enough space to create lots of large files to create valid tests).

Runtime environment

These are ruby programs, and so it does require that you have ruby version 2 installed on your system.

These programs will only run under Linux. The applications have been tested under Ubuntu, but should work under any Linuxes, not are unlikely to work on other operating systems.

The applications have the file in the incs directory located under the directory in which the application source files exist.

When running sdtest.rb the percentages when creating new files is the percentage remaining (i.e. the percentage decreases as it progresses), while the percentages when reading the files is the percentage complete (i.e. the percentage increases as it progresses).