On Sun, Jan 24, 2010 at 10:50 PM, Nick Holland <n...@holland-consulting.net> wrote: > nixlists wrote: >> On Sun, Jan 24, 2010 at 9:18 PM, Marco Peereboom <sl...@peereboom.us> wrote: >>>> I specifically wrote above "When configured as documented." No admin >>>> will run a mail server with write-back cache enabled on either >>>> controller or drives (well, maybe with a battery back-up, but I'll say >>>> again that batteries fail too). You seem to be taking what I wrote out >>>> of context, or you are assuming that I am a moron who doesn't know the >>>> basics and run mail servers with write-back cache on controllers and >>>> drives. >>> >>> No one disables WB cache for 2 reasons: >> >> Are you speaking for everybody? This is simply not true. >> >>> 1. They don't know how >> >> Unless I am missing something, this is not true... I disable it, It's >> right in my RAID controller's config. > > you just proved Marco's point.
No I didn't. > He was talking about the writeback on the drive, you talked about it > on the controller. Fine, you disabled it on the controller. Drive is That's not true. You are either sabotaging or haven't even read my initial email in this thread. I specifically mentioned the common, and the only case for mailservers that makes sense - write-back cache turned off on both controllers and drives. > still doing write caching. Maybe. You don't really know. What do you No, I as already mentioned also disabled it on the drives. Please don't twist what I said around to sabotage. This is becoming hilarious, and shows OpenBSD's users/developers psychology. > think that 2M-16+M cache on the drive is doing? How do you know? > > Nick. As I said - I may not know the controller/disk nuances, but at least I can run some simple benchmarks, and see how much slower the writes become after the cache is off (just to be sure no one pretends to have misread again - ON BOTH THE DRIVES AND THE CONTROLLER). Now it would be nice to hear Marco's answer whether the drives and the controller, as I already asked, continue caching or some such thing. This information is important for mail server admins.
