On Wed, 21 Mar 2012, Holger Kiehl wrote: > On Tue, 20 Mar 2012, Hugh Dickins wrote: > > > > It appears to be a bug in the Vertex 2: I did receive one other such > > report on a Vertex 2 fourteen months ago, and in the absence of further > > reports, we decided to consider that user's drive defective. I wonder > > if Holger's drive is defective, or if it's true of all Vertex 2s, or > > if it depends on the firmware revision, and a later revision fixes it. > > > I have three of those drives put together via MD to a raid 0 and I do > not think they are defective, since they worked (without discard) so far. > Firmware is also the new-es it's 1.35, just checked with OCZ website. Thanks very much for checking and reporting back. > > Thank you for the pointer with the firmware, I have posted a support > question at OCZ. Great: please let me know if they have anything of interest to add. I've now ordered a Vertex2 myself, to see if it sheds any light on what goes on. Probably not; but my Vertex1 has recently started giving errors, so I might as well use a 2 to replace it. By the time I came to investigate last year's report, the Vertex3 was imminent, so I held on for that; but it turned out not to share the problem. > > But if there's no good firmware for the Vertex 2, I'm not so sure > > what to do: two reports in fourteen months, on a superseded drive - > > is that strong enough to disable a feature which appeared to offer > > some advantage on others? > > > No, I agree that one should not disable a feature that is useful to so > many, for the reasons you mention. However, it would be good if there > is some way to disable this, other then having to always patch the kernel. I should not exaggerate the effectiveness of the swapon at discard, on any drive I tried: "useful to so many" is probably going too far. I've called the effect "slight": when I've time I shall measure again just what that amounts to, and whether it's worth the effort of doing anything cleverer than Shaohua's patch - quite possibly not. Hugh -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>