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From: Warner Losh <imp@bsdimp.com>
Date: Mon, 18 Apr 2022 11:47:27 -0600
Message-ID: <CANCZdfr7u0Emk=+6butKsjAgYcgJhvTZu3rv7X6N6Pozdx7tcA@mail.gmail.com>
Subject: WWN
To: freebsd-scsi <freebsd-scsi@freebsd.org>
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Is there a reason we don't rely primarily on WWN changing to detect a disk
change at a particular location? I know it's not universally available, but
anything made in the last 15 or 20 years should have one if my research is
correct... Or is this just a case of inertia?
I'm looking at making ahci a little more resilient to transient outages,
and thought it might be best to key primarily off this and secondarily off
other changed information when that's not available. If I had a WWN, then
I'd know the disk that was gone for 500ms is the same one and I could
resume its operations and still detect that someone unplugged drive A and
plugged in drive B.
Warner
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<div dir=3D"ltr">Is there a reason we don't rely primarily on WWN chang=
ing to detect a disk change at a particular location? I know it's not u=
niversally available, but anything made in the last 15 or 20 years should h=
ave one if my research is correct... Or is this just a case of inertia?<div=
><br></div><div>I'm looking at making ahci a little more resilient to t=
ransient outages, and thought it might be best to key primarily off this an=
d secondarily off other changed information when that's not available. =
If I had a WWN, then I'd know the disk that was gone for 500ms is the s=
ame one and I could resume its operations and still detect that someone unp=
lugged drive A and plugged in drive B.<br><div><br></div><div>Warner</div><=
div><br></div></div></div>
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