Date: Tue, 03 Mar 1998 16:13:29 -0800 (PST) From: Simon Shapiro <shimon@simon-shapiro.org> To: Wilko Bulte <wilko@yedi.iaf.nl> Cc: grog@lemis.com, hackers@FreeBSD.ORG, blkirk@float.eli.net, jdn@acp.qiv.com, tlambert@primenet.com, sbabkin@dcn.att.com Subject: Re: SCSI Bus redundancy... Message-ID: <XFMail.980303161329.shimon@simon-shapiro.org> In-Reply-To: <199803032147.WAA03990@yedi.iaf.nl>
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On 03-Mar-98 Wilko Bulte wrote: ... > The trick is cute, but it was used to park heads in the drives I saw. > Not for flushing on drive caches. There would not be enough power to > do e.g. a seek in order flush the cache. And by definition your platter > rpm is dead wrong, you essentially use the whole thing as a > electromagnetic brake. Not nice. I could swear the old Priam 14" had something like 0.5 sec before RPM will degrad. And I am pretty sure it could flush all 2K of cache (2 seeks and two rotations worst case with 1k sectors), but I could be wrong. Most modern drives use the motor as an electromagnetic break. Try to snap off the motor leads and you see the difference in spin-down time. I have :-) ---------- Sincerely Yours, Simon Shapiro Shimon@Simon-Shapiro.ORG Voice: 503.799.2313 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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