A simple test for damaged disks

WARNING !!! ... This test will destroy the partition table and the beginning of the first partition. It can be done only as a last resort.

dd if=/dev/urandom of=test.img bs=65536 count=16

cat test.img > /dev/daX

dd if=/dev/daX of=test_rb.img bs=65536 count=16

diff test.img test_rb.img

If these files differs you have problems with disk.

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