This is not an issue of performance, it is an issue of data durability in the face of power loss.
For fsync and fsyncdata to work correctly, they must flush file data to the disk platters before returning so that the calling application can be confident that the transaction is durable. All applications that use this system call depend on the system to correctly flush file data. This includes all database systems, mail servers and other software. Disks rotate at about 100 revolutions per second. This means that the number of fsync or fsyncdata calls in a single-threaded application cannot be more than 100 per second if data is flushed correctly to the disk. The fact that the test program runs at more than 1000 calls per second means that data is not flushed correctly to disk. Does this clarify the problem? -- ext3/4 fsyncdata does not flush disk cache https://bugs.launchpad.net/bugs/504632 You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
