Date: Mon, 11 Jul 2016 08:56:41 -0500 From: Karl Denninger <karl@denninger.net> To: freebsd-stable@freebsd.org Subject: Re: Not-so stable if you take a CAM error.... Message-ID: <155d322e-01c9-ef36-bc68-5c3a58835bb6@denninger.net> In-Reply-To: <CAKFCL4WrRS1ic1CZqcmbCEnsrD2pkh4VHPBFyB%2B-3NaNJZ%2BJkw@mail.gmail.com> References: <2b0c454b-c1a0-4b5b-e778-bf0939e90ae1@denninger.net> <op.ykfe1fvbkndu52@ronaldradial.radialsg.local> <6e9c07e1-12a6-a7cd-f775-6b0fe5a706bc@denninger.net> <1468243977.72182.118.camel@freebsd.org> <877f5e8e-c1e7-6fb0-6ceb-031ce3e68582@denninger.net> <CAKFCL4WrRS1ic1CZqcmbCEnsrD2pkh4VHPBFyB%2B-3NaNJZ%2BJkw@mail.gmail.com>
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This is a cryptographically signed message in MIME format. --------------ms070808020806030501060403 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable On 7/11/2016 08:50, Brandon Allbery wrote: > On Mon, Jul 11, 2016 at 9:46 AM, Karl Denninger <karl@denninger.net> wr= ote: > >> Here's the backtrace ... sounds like expected behavior, which is not-s= o >> good all-in for a situation like this. I guess the strategy is to tur= n >> off softupdates before attempting such an update so as not to crash th= e >> host machine if there's a problem with the card. >> > I would tend to assume that removable media should not have softupdates= > enabled. Even with properly working media, it's practically begging for= > corruption. But it's not normally "removable media" -- which is the point. The operation in question occurs when you take a storage device out of an embedded machine (where softupdates has a material positive performance impact in that it obviates the need for most fsck-on-boot operations before the system comes up) and mount it temporarily to update it on a second device. It appears, however, that to prevent crashing the updating machine you first need to make sure softupdates is off (tunefs it) and then turn it back on when done -- otherwise you risk this outcome in the event there is an unknown write error lurking around. Oh, and for flash-based media those errors are *frequently* going to be unknown in advance -- I suspect the reason it occurred is that the card in question ran out of reallocation blocks and took a write error which would normally cause it to use a spare, but it has no spares left and thus returns a hard error. The existing data on the card at that point is still readable, but you can't make changes since a write on such a card invokes a read/erase/write cycle. --=20 Karl Denninger karl@denninger.net <mailto:karl@denninger.net> /The Market Ticker/ /[S/MIME encrypted email preferred]/ --------------ms070808020806030501060403 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwEAAKCC Bl8wggZbMIIEQ6ADAgECAgEpMA0GCSqGSIb3DQEBCwUAMIGQMQswCQYDVQQGEwJVUzEQMA4G A1UECBMHRmxvcmlkYTESMBAGA1UEBxMJTmljZXZpbGxlMRkwFwYDVQQKExBDdWRhIFN5c3Rl bXMgTExDMRwwGgYDVQQDExNDdWRhIFN5c3RlbXMgTExDIENBMSIwIAYJKoZIhvcNAQkBFhND dWRhIFN5c3RlbXMgTExDIENBMB4XDTE1MDQyMTAyMjE1OVoXDTIwMDQxOTAyMjE1OVowWjEL MAkGA1UEBhMCVVMxEDAOBgNVBAgTB0Zsb3JpZGExGTAXBgNVBAoTEEN1ZGEgU3lzdGVtcyBM TEMxHjAcBgNVBAMTFUthcmwgRGVubmluZ2VyIChPQ1NQKTCCAiIwDQYJKoZIhvcNAQEBBQAD ggIPADCCAgoCggIBALmEWPhAdphrWd4K5VTvE5pxL3blRQPyGF3ApjUjgtavqU1Y8pbI3Byg XDj2/Uz9Si8XVj/kNbKEjkRh5SsNvx3Fc0oQ1uVjyCq7zC/kctF7yLzQbvWnU4grAPZ3IuAp 3/fFxIVaXpxEdKmyZAVDhk9az+IgHH43rdJRIMzxJ5vqQMb+n2EjadVqiGPbtG9aZEImlq7f IYDTnKyToi23PAnkPwwT+q1IkI2DTvf2jzWrhLR5DTX0fUYC0nxlHWbjgpiapyJWtR7K2YQO aevQb/3vN9gSojT2h+cBem7QIj6U69rEYcEDvPyCMXEV9VcXdcmW42LSRsPvZcBHFkWAJqMZ Myiz4kumaP+s+cIDaXitR/szoqDKGSHM4CPAZV9Yh8asvxQL5uDxz5wvLPgS5yS8K/o7zDR5 vNkMCyfYQuR6PAJxVOk5Arqvj9lfP3JSVapwbr01CoWDBkpuJlKfpQIEeC/pcCBKknllbMYq yHBO2TipLyO5Ocd1nhN/nOsO+C+j31lQHfOMRZaPQykXVPWG5BbhWT7ttX4vy5hOW6yJgeT/ o3apynlp1cEavkQRS8uJHoQszF6KIrQMID/JfySWvVQ4ksnfzwB2lRomrdrwnQ4eG/HBS+0l eozwOJNDIBlAP+hLe8A5oWZgooIIK/SulUAsfI6Sgd8dTZTTYmlhAgMBAAGjgfQwgfEwNwYI KwYBBQUHAQEEKzApMCcGCCsGAQUFBzABhhtodHRwOi8vY3VkYXN5c3RlbXMubmV0Ojg4ODgw CQYDVR0TBAIwADARBglghkgBhvhCAQEEBAMCBaAwCwYDVR0PBAQDAgXgMCwGCWCGSAGG+EIB DQQfFh1PcGVuU1NMIEdlbmVyYXRlZCBDZXJ0aWZpY2F0ZTAdBgNVHQ4EFgQUxRyULenJaFwX RtT79aNmIB/u5VkwHwYDVR0jBBgwFoAUJHGbnYV9/N3dvbDKkpQDofrTbTUwHQYDVR0RBBYw FIESa2FybEBkZW5uaW5nZXIubmV0MA0GCSqGSIb3DQEBCwUAA4ICAQBPf3cYtmKowmGIYsm6 eBinJu7QVWvxi1vqnBz3KE+HapqoIZS8/PolB/hwiY0UAE1RsjBJ7yEjihVRwummSBvkoOyf G30uPn4yg4vbJkR9lTz8d21fPshWETa6DBh2jx2Qf13LZpr3Pj2fTtlu6xMYKzg7cSDgd2bO sJGH/rcvva9Spkx5Vfq0RyOrYph9boshRN3D4tbWgBAcX9POdXCVfJONDxhfBuPHsJ6vEmPb An+XL5Yl26XYFPiODQ+Qbk44Ot1kt9s7oS3dVUrh92Qv0G3J3DF+Vt6C15nED+f+bk4gScu+ JHT7RjEmfa18GT8DcT//D1zEke1Ymhb41JH+GyZchDRWtjxsS5OBFMzrju7d264zJUFtX7iJ 3xvpKN7VcZKNtB6dLShj3v/XDsQVQWXmR/1YKWZ93C3LpRs2Y5nYdn6gEOpL/WfQFThtfnat HNc7fNs5vjotaYpBl5H8+VCautKbGOs219uQbhGZLYTv6okuKcY8W+4EJEtK0xB08vqr9Jd0 FS9MGjQE++GWo+5eQxFt6nUENHbVYnsr6bYPQsZH0CRNycgTG9MwY/UIXOf4W034UpR82TBG 1LiMsYfb8ahQJhs3wdf1nzipIjRwoZKT1vGXh/cj3gwSr64GfenURBxaFZA5O1acOZUjPrRT n3ci4McYW/0WVVA3lDGCBRMwggUPAgEBMIGWMIGQMQswCQYDVQQGEwJVUzEQMA4GA1UECBMH RmxvcmlkYTESMBAGA1UEBxMJTmljZXZpbGxlMRkwFwYDVQQKExBDdWRhIFN5c3RlbXMgTExD MRwwGgYDVQQDExNDdWRhIFN5c3RlbXMgTExDIENBMSIwIAYJKoZIhvcNAQkBFhNDdWRhIFN5 c3RlbXMgTExDIENBAgEpMA0GCWCGSAFlAwQCAwUAoIICTTAYBgkqhkiG9w0BCQMxCwYJKoZI hvcNAQcBMBwGCSqGSIb3DQEJBTEPFw0xNjA3MTExMzU2NDFaME8GCSqGSIb3DQEJBDFCBECc LA+fEoxkLDlcT/x4evG5cPw51yMilI1xAOVj4aWmEOD7uIDT7cNTvpEPoKO4AB+JBYOl51Kx qD9ozUBMo/J+MGwGCSqGSIb3DQEJDzFfMF0wCwYJYIZIAWUDBAEqMAsGCWCGSAFlAwQBAjAK BggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwICAUAwBwYFKw4DAgcwDQYI KoZIhvcNAwICASgwgacGCSsGAQQBgjcQBDGBmTCBljCBkDELMAkGA1UEBhMCVVMxEDAOBgNV BAgTB0Zsb3JpZGExEjAQBgNVBAcTCU5pY2V2aWxsZTEZMBcGA1UEChMQQ3VkYSBTeXN0ZW1z IExMQzEcMBoGA1UEAxMTQ3VkYSBTeXN0ZW1zIExMQyBDQTEiMCAGCSqGSIb3DQEJARYTQ3Vk YSBTeXN0ZW1zIExMQyBDQQIBKTCBqQYLKoZIhvcNAQkQAgsxgZmggZYwgZAxCzAJBgNVBAYT AlVTMRAwDgYDVQQIEwdGbG9yaWRhMRIwEAYDVQQHEwlOaWNldmlsbGUxGTAXBgNVBAoTEEN1 ZGEgU3lzdGVtcyBMTEMxHDAaBgNVBAMTE0N1ZGEgU3lzdGVtcyBMTEMgQ0ExIjAgBgkqhkiG 9w0BCQEWE0N1ZGEgU3lzdGVtcyBMTEMgQ0ECASkwDQYJKoZIhvcNAQEBBQAEggIAOFgw2rhz pCg3/C75OEJ9YSEgUoO1ttPUWGtHPT5uEFR0+A+K30j3JvNo79NI/5jkkFjlD4GUdxAMAu05 qJ+TmmPJZ4uTRdh6lIVCzUxCgiqszkcxusSM5VH4YBKefuCIU5AO7K6NnmTJAwGaO8/xl02k J7x+CciTh5TPGjmRl6toM2X20oDVGXjoTSuZ+uuCKOKnQ2XqlQJFJHChBfs9hLoxJewlONEf ri3nUz/K1v9rkrF+T/3wNMjnqsW9EDE0PFlI9NrlLaWe3UcWlEaI/L/N97IdO9N8pv58pO8c OfZb97ArYoJmsuhpz0WtC7oF9DFSrVIjwPq8fcBIkRDWSbFCt9XLWYSBS7Ze7wL+V+rnwa0F XXhIb03y5p19TAlThkGJApCqTtvoojELwM3lFYfwRbdf/0D4bBkR0By1jxwTP8yfFsKtH2ay b/95OFwDgF6SKMJ7zHYzzNo6q5ZyUJB7FIl4xOSOVOeHJ8g09zQWvQDwqY5xfLKmuhP/xV1X s+gvIcvveKu9kCQWdgu+N8SrCPCOPp5YBT5Mr77Do+cOdHzF9jtek0pkV+D3GKywNHzsPInJ T8CPTUdrhY9rRoC/d8iGppw7AXTHjpkRsczxR5+buYQ9T4H8KTQ81DTHnbVvmrV8xVIQI2g/ djKgSQO04vLw4OMF2B+A1Zs5cfoAAAAAAAA= --------------ms070808020806030501060403--
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