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Brent Bradburn
Brent Bradburn
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Using rsync to verify the integrity of a duplicate

To guarantee that this test physically re-reads the files from the drive media, I suggest powering-down both drives and restarting them before running this test. This will clear their internal volatile caches.

If not also restarting Linux, you should at least drop the caches (*) with:

sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'

Then to re-read both trees and compare their checksums:

rsync --dry-run --checksum --itemize-changes --archive SRC DEST

Modern rsync checksum uses MD5, which is 128 bits. The likelihood of this failing to detect an error in an individual file is astronomically low (some discussion here), but not impossible.

Using rsync to verify the integrity of a duplicate

To guarantee that this test physically re-reads the files from the drive media, I suggest powering-down both drives and restarting them before running this test. This will clear their internal volatile caches.

If not also restarting Linux, you should at least drop the caches (*) with:

sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'

Then to re-read both trees and compare their checksums:

rsync --dry-run --checksum --itemize-changes SRC DEST

Modern rsync checksum uses MD5, which is 128 bits. The likelihood of this failing to detect an error in an individual file is astronomically low (some discussion here), but not impossible.

Using rsync to verify the integrity of a duplicate

To guarantee that this test physically re-reads the files from the drive media, I suggest powering-down both drives and restarting them before running this test. This will clear their internal volatile caches.

If not also restarting Linux, you should at least drop the caches (*) with:

sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'

Then to re-read both trees and compare their checksums:

rsync --dry-run --checksum --itemize-changes --archive SRC DEST

Modern rsync checksum uses MD5, which is 128 bits. The likelihood of this failing to detect an error in an individual file is astronomically low (some discussion here), but not impossible.

Source Link
Brent Bradburn
Brent Bradburn
  • 1.3k
  • 1
  • 14
  • 23

Using rsync to verify the integrity of a duplicate

To guarantee that this test physically re-reads the files from the drive media, I suggest powering-down both drives and restarting them before running this test. This will clear their internal volatile caches.

If not also restarting Linux, you should at least drop the caches (*) with:

sudo sh -c 'echo 3 > /proc/sys/vm/drop_caches'

Then to re-read both trees and compare their checksums:

rsync --dry-run --checksum --itemize-changes SRC DEST

Modern rsync checksum uses MD5, which is 128 bits. The likelihood of this failing to detect an error in an individual file is astronomically low (some discussion here), but not impossible.