On 10-12-06 09:00 PM, Josh Berkus wrote:
> Steve,
>
>> If you tell me which options to pgbench and which .conf file settings
>> you'd like to see I can probably arrange to run some tests on AIX.
>
> Compile and run test_fsync in PGSRC/src/tools/fsync.
>
Attached are runs against two different disk sub-systems from a server
running AIX 5.3.
The first one is against the local disks
Loops = 10000
Simple write: 8k write 60812.454/second
Compare file sync methods using one write: open_datasync 8k write 162.160/second open_sync 8k
write 158.472/second 8k write, fdatasync 158.157/second 8k write, fsync
45.382/second
Compare file sync methods using two writes: 2 open_datasync 8k writes 79.472/second 2 open_sync 8k
writes 80.095/second 8k write, 8k write, fdatasync 159.268/second 8k write, 8k write, fsync
44.725/second
Compare open_sync with different sizes: open_sync 16k write 162.017/second 2 open_sync 8k
writes 79.709/second
Test if fsync on non-write file descriptor is honored:
(If the times are similar, fsync() can sync data written
on a different descriptor.) 8k write, fsync, close 45.361/second 8k write, close, fsync
36.311/second
================================
The below profile is from the same machine using an IBM DS 6800 SAN for
storage.
Loops = 10000
Simple write: 8k write 75933.027/second
Compare file sync methods using one write: open_datasync 8k write 2762.801/second open_sync 8k
write 2453.822/second 8k write, fdatasync 2867.331/second 8k write, fsync
1094.048/second
Compare file sync methods using two writes: 2 open_datasync 8k writes 1287.845/second 2 open_sync 8k
writes 1332.084/second 8k write, 8k write, fdatasync 1966.411/second 8k write, 8k write, fsync
1048.354/second
Compare open_sync with different sizes: open_sync 16k write 2281.425/second 2 open_sync 8k
writes 1401.561/second
Test if fsync on non-write file descriptor is honored:
(If the times are similar, fsync() can sync data written
on a different descriptor.) 8k write, fsync, close 1298.404/second 8k write, close, fsync
1188.582/second