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axboe
fsync is not working properly with nrfiles
When nrfiles is set to 2 and fsync is set to 1, the sync system call is only executed after each write operation for the first file. This results in the following pattern for the first file:
Write
Sync
Write
Sync
Write
Sync
For the second file, the sync system call is not executed after each write operation.
Write
Write
Write
Flush
When nrfiles is increased to 3, the sync system call is only executed after each write operation for the first two file. The third file is not subject to any sync calls.
In summary, the sync behavior for files is determined by the value of nrfiles. When nrfiles is set to 1, all files are synced after each write operation. When nrfiles is greater than 1, only the first nrfiles-1 files are synced after each write operation.
e.g.
nrfiles=3
fsync=1
filesize=3M
bs=1M
calls for 1st file
calls for 2nd file
calls for 3rd file
