-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 02/04/2014 04:58 PM, Stan Hoeppner wrote: > Yes, I stated that in this post > > http://www.spinics.net/lists/raid/msg45726.html > > in the context of achieving greater throughput with an FIO job > file configured to use O_DIRECT, a job file I created, that the OP > was using for testing. That job file is quoted further down in > this same post, and is included in my posts prior this one in the > thread. Apparently you ignored them. The context of my comment > above is clearly established multiple times earlier in the thread. > > In my paragraph directly preceding the statement you quote above, > I stated this: > > "Serial submission typically doesn't reach peak throughput... You > usually must submit asynchronously or in parallel to reach maximum > throughput." > > And again this is in the context of the FIO job file using > O_DIRECT, and this statement is factual. As I repeated earlier > today, O_DIRECT is used because measuring actual throughput at the > disks is straightforward. To increase O_DIRECT write throughput in > FIO, you typically need parallel submission or AIO. This is well > known. Ahh, I did not gather that O_DIRECT was already assumed. In that case, then I was simply restating the same thing: that you want aio with O_DIRECT, but otherwise, buffered IO works fine too ( which is what the OP was using with dd, which is why it sounded like you were saying not to do that, that you must use O_DIRECT + aio because buffered IO won't get you the performance you're looking for ). -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.14 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCgAGBQJS8ZGfAAoJEI5FoCIzSKrw43gH/2sUIEVB97YOGpTj5H8XkySb wJAQxU//LyZRcUiK37TNeIF+6QUfqVtD/VFYxjTFfV8gmLSmu7JzwfMZQjJ2Rrb5 I08Pks2xCrU/XvfLKqum5JQHreJaz8jQQVIByXAziDAj+H46k5NV34rUNDP5glyk 18uKN1ty0//jyKNlzWhRZllw7Uo7CAvJvfTHSxvoTGgTmzeea2Q6eADIv0Ov96Lb ZeNKnZXTwDyIXskEduDToWQdGL01TYSKXiV8zTqnhMsMBUZ33oE7r5l+a/o/m6Kv ZKWE+JG/5xzZiFipNj1ELYuPwM/SD6cCPBRfwh2tWmKTG3Z/waD+kjytIwieUDY= =1T19 -----END PGP SIGNATURE----- -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
