On Fri, Nov 07, 2008 at 10:36:24AM -0500, Theodore Tso wrote: > The discussion here has been around Intel-style SSD's, which > apparently have a log-structured filesystem in the device, such that > wear leveling is done automatically, and in fact it is *better* for > these devices if we reuse the same block since then the SSD > automatically knows that contents at the old location is logically > "gone". (I don't believe, or at least don't see, why there would be > any benefit of reusing block ranges versus explicitly using a TRIM > command to tell the SSD that the old block was no longer being used; > it should have the same effect as far as the SSD is concerned.) > > The one thing which I am somewhat concerned about is whether all SSD's > will be doing things the Intel way, or whether other SSD's might not Given that most of my information about how SSDs work comes from a presentation given by Samsung at the FS/IO storage workshop, I feel fairly confident all the manufacturers do something very similar with a log-structured FS internally. Of course, this probably doesn't apply to the $5 1Gb USB keys that you get in the conference schwag, but if we start optimising for those, we've probably already lost. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- 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
