Должен ли diff ничего не возвращать после rsync?

Question

Я только что создал резервную копию с

rsync -av --delete projects/ /Volumes/daten/projects/

После этого я запустил

diff -r projects/ /Volumes/daten/projects/

, просто чтобы проверить, все ли нормально, не ожидая вывода из diff.Однако diff обнаружил много различий.Означает ли это, что rsync неправильно синхронизировал мои данные?

Обновление: При повторном запуске rsync все выглядит нормально, для rsync делать нечего:

$ rsync -av --delete projects/ /Volumes/daten/projects/
building file list ... done

sent 470414 bytes  received 20 bytes  188173.60 bytes/sec
total size is 295619054  speedup is 628.40

Однако, diff не останавливает генерацию вывода, как будто есть много разных файлов.Вот небольшая выдержка:

$ diff -r projects/ /Volumes/daten/projects/
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_dep/debug/package_dependencies/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_dep/debug/package_dependencies/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:41 CST 2018
---
> #Sun Nov 04 19:34:13 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_1/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_1/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:41 CST 2018
---
> #Sun Nov 04 19:34:14 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_2/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_2/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:41 CST 2018
---
> #Sun Nov 04 19:34:14 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_3/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_3/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:42 CST 2018
---
> #Sun Nov 04 19:34:14 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_4/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_4/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:42 CST 2018
---
> #Sun Nov 04 19:52:00 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_5/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_5/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:42 CST 2018
---
> #Sun Nov 04 19:34:14 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_6/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_6/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:42 CST 2018
---
> #Sun Nov 04 19:34:14 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_7/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_7/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:42 CST 2018
---
> #Sun Nov 04 19:34:14 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_8/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_8/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:42 CST 2018
---
> #Sun Nov 04 19:34:14 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_9/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/ir_slices/debug/package_slice_9/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:42 CST 2018
---
> #Sun Nov 04 19:34:14 CET 2018
diff -r projects/CatClicker/app/build/intermediates/incremental/packageInstantRunResourcesDebug/tmp/debug/dex-renamer-state.txt /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental/packageInstantRunResourcesDebug/tmp/debug/dex-renamer-state.txt
1c1
< #Sat Dec 08 16:17:34 CST 2018
---
> #Sun Nov 04 19:33:52 CET 2018
Binary files projects/CatClicker/app/build/intermediates/incremental-classes/debug/instant-run-bootstrap.jar and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-classes/debug/instant-run-bootstrap.jar differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/compat/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/compat/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/coreui/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/coreui/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/coreutils/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/coreutils/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/fragment/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/fragment/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/graphics/drawable/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/graphics/drawable/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/graphics/drawable/animated/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/graphics/drawable/animated/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/mediacompat/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/mediacompat/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v4/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v4/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v7/appcompat/R$anim.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v7/appcompat/R$anim.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v7/appcompat/R$color.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/android/support/v7/appcompat/R$color.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$attr.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$attr.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$bool.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$bool.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$dimen.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$dimen.class differ
Binary files projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$drawable.class and /Volumes/daten/projects/CatClicker/app/build/intermediates/incremental-verifier/debug/cyberdynesoftware/catclicker/R$drawable.class differ

Answer 1

Похоже, что многие файлы не считаются rsync «разными».По умолчанию rsync проверяет только размеры файлов и отметки времени последнего изменения файлов.Попробуйте использовать rsync с опцией -c/--checksum, чтобы включить контрольную сумму и снова запустить "diff".

Выдержка из справочной страницы rsync:

-c, --checksum

Это изменяет способ, которым rsync проверяет, были ли файлы изменены и нуждаются в передаче.Без этой опции rsync использует «быструю проверку», которая (по умолчанию) проверяет, совпадают ли размер файла и время последней модификации между отправителем и получателем.Эта опция изменяет это, чтобы сравнивать 128-битную контрольную сумму для каждого файла, который имеет соответствующий размер.Генерация контрольных сумм означает, что обе стороны будут тратить много дискового ввода-вывода на чтение всех данных в файлах при передаче (и это до любого чтения, которое будет выполнено для передачи измененных файлов), поэтому это может замедлить процессзначительно.