On 04/30/2015 06:48 AM, Mike Galbraith wrote: > On Thu, 2015-04-30 at 05:58 -0700, Daniel Phillips wrote: >> On Thursday, April 30, 2015 5:07:21 AM PDT, Mike Galbraith wrote: >>> On Thu, 2015-04-30 at 04:14 -0700, Daniel Phillips wrote: >>> >>>> Lovely sounding argument, but it is wrong because Tux3 still beats XFS >>>> even with seek time factored out of the equation. >>> >>> Hm. Do you have big-storage comparison numbers to back that? I'm no >>> storage guy (waiting for holographic crystal arrays to obsolete all this >>> crap;), but Dave's big-storage guy words made sense to me. >> >> This has nothing to do with big storage. The proposition was that seek >> time is the reason for Tux3's fsync performance. That claim was easily >> falsified by removing the seek time. >> >> Dave's big storage words are there to draw attention away from the fact >> that XFS ran the Git tests four times slower than Tux3 and three times >> slower than Ext4. Whatever the big storage excuse is for that, the fact >> is, XFS obviously sucks at little storage. > > If you allocate spanning the disk from start of life, you're going to > eat seeks that others don't until later. That seemed rather obvious and > straight forward. It is a logical falacy. It mixes a grain of truth (spreading all over the disk causes extra seeks) with an obvious falsehood (it is not necessarily the only possible way to avoid long term fragmentation). > He flat stated that xfs has passable performance on > single bit of rust, and openly explained why. I see no misdirection, > only some evidence of bad blood between you two. Raising the spectre of theoretical fragmentation issues when we have not even begun that work is a straw man and intellectually dishonest. You have to wonder why he does it. It is destructive to our community image and harmful to progress. > No, I won't be switching to xfs any time soon, but then it would take a > hell of a lot of evidence to get me to move away from ext4. I trust > ext[n] deeply because it has proven many times over the years that it > can take one hell of a lot (of self inflicted wounds;). Regards, Daniel -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
