| 1 | # Writing to 2 files that share the duplicate blocks. |
| 2 | # The dedupe working set is spread uniformly such that when |
| 3 | # each of the jobs choose to perform a dedup operation they will |
| 4 | # regenerate a buffer from the global space. |
| 5 | # If you test the dedup ratio on either file by itself the result |
| 6 | # is likely lower than if you test the ratio of the two files combined. |
| 7 | # |
| 8 | # Use `./t/fio-dedupe <file> -C 1 -c 1 -b 4096` to test the total |
| 9 | # data reduction ratio. |
| 10 | # |
| 11 | # |
| 12 | # Full example of test: |
| 13 | # $ ./fio ./examples/dedupe-global.fio |
| 14 | # |
| 15 | # Checking ratio on a and b individually: |
| 16 | # $ ./t/fio-dedupe a.0.0 -C 1 -c 1 -b 4096 |
| 17 | # |
| 18 | # $ Extents=25600, Unique extents=16817 Duplicated extents=5735 |
| 19 | # $ De-dupe ratio: 1:0.52 |
| 20 | # $ De-dupe working set at least: 22.40% |
| 21 | # $ Fio setting: dedupe_percentage=34 |
| 22 | # $ Unique capacity 33MB |
| 23 | # |
| 24 | # ./t/fio-dedupe b.0.0 -C 1 -c 1 -b 4096 |
| 25 | # $ Extents=25600, Unique extents=17009 Duplicated extents=5636 |
| 26 | # $ De-dupe ratio: 1:0.51 |
| 27 | # $ De-dupe working set at least: 22.02% |
| 28 | # $ Fio setting: dedupe_percentage=34 |
| 29 | # $ Unique capacity 34MB |
| 30 | # |
| 31 | # Combining files: |
| 32 | # $ cat a.0.0 > c.0.0 |
| 33 | # $ cat b.0.0 >> c.0.0 |
| 34 | # |
| 35 | # Checking data reduction ratio on combined file: |
| 36 | # $ ./t/fio-dedupe c.0.0 -C 1 -c 1 -b 4096 |
| 37 | # $ Extents=51200, Unique extents=25747 Duplicated extents=11028 |
| 38 | # $ De-dupe ratio: 1:0.99 |
| 39 | # $ De-dupe working set at least: 21.54% |
| 40 | # $ Fio setting: dedupe_percentage=50 |
| 41 | # $ Unique capacity 51MB |
| 42 | # |
| 43 | [global] |
| 44 | ioengine=libaio |
| 45 | iodepth=256 |
| 46 | size=100m |
| 47 | dedupe_mode=working_set |
| 48 | dedupe_global=1 |
| 49 | dedupe_percentage=50 |
| 50 | blocksize=4k |
| 51 | rw=write |
| 52 | buffer_compress_percentage=50 |
| 53 | dedupe_working_set_percentage=50 |
| 54 | |
| 55 | [a] |
| 56 | |
| 57 | [b] |