Date: Mon, 11 Sep 2000 14:17:18 -0600 From: "Kenneth D. Merry" <ken@kdm.org> To: Rahul Dhesi <dhesi@rahul.net> Cc: freebsd-stable@FreeBSD.ORG Subject: Re: SCSI retries without errors in /var/log/messages? Message-ID: <20000911141718.A51045@panzer.kdm.org> In-Reply-To: <Pine.BSF.4.21.0009111224470.32306-100000@yellow.rahul.net>; from dhesi@rahul.net on Mon, Sep 11, 2000 at 12:27:37PM -0700 References: <20000911130644.A50024@panzer.kdm.org> <Pine.BSF.4.21.0009111224470.32306-100000@yellow.rahul.net>
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(you'll get faster replies by CCing things to me instead of just sending them to the list) On Mon, Sep 11, 2000 at 12:27:37 -0700, Rahul Dhesi wrote: > Correct me if I am wrong please: > > Kenneth D. Merry wrote: > > > SCSI errors that we recover from aren't logged. > > So is it possible to have very low SCSI throughput, due to many > recoverable errors, yet have no SCSI error logged because all errors > were recoverable? It is possible, yes. I don't think it is very probable, but it could happen. The timeout for read and write operations in the da(4) driver is 60 seconds, and we retry things four times. Theoretically, the drive could take say 50 seconds to return an error on a read or write, and do that four times, and then return good status the last time. So, in that scenario, you could have a period of 200 seconds where a particular read or write command wasn't returned. That's a pretty rare situation, though. My guess is that something else is going on. Ken -- Kenneth Merry ken@kdm.org To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message
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