On Fri, Nov 07, 2008 at 09:26:49AM -0500, Ric Wheeler wrote: > One more consideration that I should have mentioned is that we can also > make our file system allocation policies "thin provisioned LUN" friendly. > > Basically, we need to try to re-allocate blocks instead of letting the > allocations happily progress across the entire block range. This might > be the inverse of an SSD friendly allocation policy, but would seem to > be fairly trivial to implement :-) It's the opposite of a _flash_ friendly policy. But SSDs are not naive flash implementations -- if you overwrite a block, it'll just write elsewhere and update its internal mapping of LBAs to sectors. I honestly think there's no difference in performance between overwriting a block and writing elsewhere ... as long as you TRIM the LBAs you're no longer using, of course ;-) -- 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-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
