Date: Thu, 14 Nov 1996 01:13:25 +0300 (MSK) From: "=?KOI8-R?Q?=E1=CE=C4=D2=C5=CA_=FE=C5=D2=CE=CF=D7?=" (Andrey A. Chernov) <ache@nagual.ru> To: gibbs@freefall.freebsd.org (Justin T. Gibbs) Cc: current@FreeBSD.org, scsi@FreeBSD.org Subject: Re: SCB paging is most dangerous option now! Message-ID: <199611132213.BAA00212@nagual.ru> In-Reply-To: <199611131606.IAA25507@freefall.freebsd.org> from "Justin T. Gibbs" at "Nov 13, 96 08:06:10 am"
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> >I read only mode I got the almost same result with SCB paging as without it. > >This bug affects _writing_only_, not reading. > >And I can't start 8 dds for each drive in both modes, > >3 dds per drive is enough to cause "Queue Full" in both modes, but > >it is harmless due to read only. > > This is probably what is causing your corruption in the SCB Paging case. > Which drive can only do 3 transactions at a time? I'm sure that your IBM > can do more. It may very well be that one of your drives doesn't like the > fact that the code with SCB paging turned on will basically continually > pound on that drive, causing queue full conditions, until there aren't > enough transactions queued to make this happen any more. The patch I > posted for Andreas' problem may help in this regard. No, _any_ of two drives says "Queue full" after 2-3 dds and goes to "timed out" state after more dds which ends up with "panic: Timed-out command times out again" It happens equally in both SCB paging and not SCB paging modes. BTW, I see it only for dds, I can start f.e. about 20 "ls -lR" safely. Does it means that Tagged Queueing not work well with 2842? > As for your problem happening on the "first write", are you sure this isn't > the "first sync" after boot?? I mean first physical write, of course. It happens just after fsck puts info lines about each drive at boot phase. -- Andrey A. Chernov <ache@nagual.ru> http://www.nagual.ru/~ache/
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