From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f171.google.com ([209.85.223.171]:36042 "EHLO mail-io0-f171.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1162313AbbKEQ3s (ORCPT ); Thu, 5 Nov 2015 11:29:48 -0500 Received: by ioll68 with SMTP id l68so96422071iol.3 for ; Thu, 05 Nov 2015 08:29:47 -0800 (PST) Received: from [127.0.0.1] (rrcs-70-62-41-24.central.biz.rr.com. [70.62.41.24]) by smtp.googlemail.com with ESMTPSA id j11sm3138199ioi.42.2015.11.05.08.29.46 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Thu, 05 Nov 2015 08:29:46 -0800 (PST) To: linux-btrfs From: Austin S Hemmelgarn Subject: Possible project idea Message-ID: <563B83DE.7070002@gmail.com> Date: Thu, 5 Nov 2015 11:29:18 -0500 MIME-Version: 1.0 Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-512; boundary="------------ms030603000202020303050608" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms030603000202020303050608 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: quoted-printable I'd been looking at the wiki page with project ideas, and I realized=20 that there were no listed ideas that suggested the adding support for=20 arbitrary erasure coding methods. Ceph for example has an option that=20 allows you to set arbitrary erasure coding such that you use n devices=20 to store the data, and can tolerate loss of any m devices out of it. Technically, this would be covered as a special case by the whole=20 copies/stripes/parity thing that was discussed a while back before=20 raid56 code made it into the kernel (I've tried to find the thread for=20 reference, but haven't been unable to locate it), but I didn't see that=20 'project' listed anywhere on the page either. IMHO, this would be an excellent feature to differentiate BTRFS from=20 bcachefs and ZFS (although I would not be surprised if they both copied=20 it themselves). --------------ms030603000202020303050608 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 Brgwgga0MIIEnKADAgECAgMRLfgwDQYJKoZIhvcNAQENBQAweTEQMA4GA1UEChMHUm9vdCBD QTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNp Z25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcwHhcN MTUwOTIxMTEzNTEzWhcNMTYwMzE5MTEzNTEzWjBjMRgwFgYDVQQDEw9DQWNlcnQgV29UIFVz ZXIxIzAhBgkqhkiG9w0BCQEWFGFoZmVycm9pbjdAZ21haWwuY29tMSIwIAYJKoZIhvcNAQkB FhNhaGVtbWVsZ0BvaGlvZ3QuY29tMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA nQ/81tq0QBQi5w316VsVNfjg6kVVIMx760TuwA1MUaNQgQ3NyUl+UyFtjhpkNwwChjgAqfGd LIMTHAdObcwGfzO5uI2o1a8MHVQna8FRsU3QGouysIOGQlX8jFYXMKPEdnlt0GoQcd+BtESr pivbGWUEkPs1CwM6WOrs+09bAJP3qzKIr0VxervFrzrC5Dg9Rf18r9WXHElBuWHg4GYHNJ2V Ab8iKc10h44FnqxZK8RDN8ts/xX93i9bIBmHnFfyNRfiOUtNVeynJbf6kVtdHP+CRBkXCNRZ qyQT7gbTGD24P92PS2UTmDfplSBcWcTn65o3xWfesbf02jF6PL3BCrVnDRI4RgYxG3zFBJuG qvMoEODLhHKSXPAyQhwZINigZNdw5G1NqjXqUw+lIqdQvoPijK9J3eijiakh9u2bjWOMaleI SMRR6XsdM2O5qun1dqOrCgRkM0XSNtBQ2JjY7CycIx+qifJWsRaYWZz0aQU4ZrtAI7gVhO9h pyNaAGjvm7PdjEBiXq57e4QcgpwzvNlv8pG1c/hnt0msfDWNJtl3b6elhQ2Pz4w/QnWifZ8E BrFEmjeeJa2dqjE3giPVWrsH+lOvQQONsYJOuVb8b0zao4vrWeGmW2q2e3pdv0Axzm/60cJQ haZUv8+JdX9ZzqxOm5w5eUQSclt84u+D+hsCAwEAAaOCAVkwggFVMAwGA1UdEwEB/wQCMAAw VgYJYIZIAYb4QgENBEkWR1RvIGdldCB5b3VyIG93biBjZXJ0aWZpY2F0ZSBmb3IgRlJFRSBo ZWFkIG92ZXIgdG8gaHR0cDovL3d3dy5DQWNlcnQub3JnMA4GA1UdDwEB/wQEAwIDqDBABgNV HSUEOTA3BggrBgEFBQcDBAYIKwYBBQUHAwIGCisGAQQBgjcKAwQGCisGAQQBgjcKAwMGCWCG SAGG+EIEATAyBggrBgEFBQcBAQQmMCQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLmNhY2Vy dC5vcmcwMQYDVR0fBCowKDAmoCSgIoYgaHR0cDovL2NybC5jYWNlcnQub3JnL3Jldm9rZS5j cmwwNAYDVR0RBC0wK4EUYWhmZXJyb2luN0BnbWFpbC5jb22BE2FoZW1tZWxnQG9oaW9ndC5j b20wDQYJKoZIhvcNAQENBQADggIBADMnxtSLiIunh/TQcjnRdf63yf2D8jMtYUm4yDoCF++J jCXbPQBGrpCEHztlNSGIkF3PH7ohKZvlqF4XePWxpY9dkr/pNyCF1PRkwxUURqvuHXbu8Lwn 8D3U2HeOEU3KmrfEo65DcbanJCMTTW7+mU9lZICPP7ZA9/zB+L0Gm1UNFZ6AU50N/86vjQfY WgkCd6dZD4rQ5y8L+d/lRbJW7ZGEQw1bSFVTRpkxxDTOwXH4/GpQfnfqTAtQuJ1CsKT12e+H NSD/RUWGTr289dA3P4nunBlz7qfvKamxPymHeBEUcuICKkL9/OZrnuYnGROFwcdvfjGE5iLB kjp/ttrY4aaVW5EsLASNgiRmA6mbgEAMlw3RwVx0sVelbiIAJg9Twzk4Ct6U9uBKiJ8S0sS2 8RCSyTmCRhJs0vvva5W9QUFGmp5kyFQEoSfBRJlbZfGX2ehI2Hi3U2/PMUm2ONuQG1E+a0AP u7I0NJc/Xil7rqR0gdbfkbWp0a+8dAvaM6J00aIcNo+HkcQkUgtfrw+C2Oyl3q8IjivGXZqT 5UdGUb2KujLjqjG91Dun3/RJ/qgQlotH7WkVBs7YJVTCxfkdN36rToPcnMYOI30FWa0Q06gn F6gUv9/mo6riv3A5bem/BdbgaJoPnWQD9D8wSyci9G4LKC+HQAMdLmGoeZfpJzKHMYIE0TCC BM0CAQEwgYAweTEQMA4GA1UEChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNl cnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcN AQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DANBglghkgBZQMEAgMFAKCCAiEwGAYJKoZI hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUxMTA1MTYyOTE4WjBPBgkq hkiG9w0BCQQxQgRASL+RXXq7XL5UoHw/DE7Y9L/Bkr6LvZtIUh2w5aPuA/9bXGE0vNzY174K AU5QmMI78/hTtW5l00S+848n8nWCnDBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxEt+DCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DAN BgkqhkiG9w0BAQEFAASCAgB0JMl1lV81nCk0XAMj+7HUmzD7+Dy2d1OtukHiw6+mqOr6nOC1 1z9cy4N8f7/hK9woJIZE07sTbvcHP0nKDXat67NXNcOfLDQBlWFeQOI0bjuDriy9FVJyjAbQ dZTg5GMKc8OkEERZWiFW2Ff/N+k/Yzqg/vBp2Cm6/XS+BS6BtEH548++NSKYJwgyJajxXTGl 9Uf6BLCmLrptr9hetPspzCNHfxcraS5HmnZ4/sAy+HTaqEFmlPK9jYmTNYiZ01hB8vuIfPXO 6bmvPaggkgMZv8ivTh/AuPGiB9vbOCM211kwz0pVDjKTzTyXoh0dbGYuoG2YJZH+CEKPcVIs 2kfRKTUy1FMT0QMteuJ4VXuODh67fo0upzPr8eKw5ApQCV8COpkmgV7xC4dhY/il91aqnV7T PxwUYlDsuKdVE6j2qSU9JnvVnxlcO8iCH9/iyMjvr1GTgXffg4Mtx5CfPlhNjQQhUZGB5QvO uLEKeVmFGVZY8yU4leIIQ+CZSJ1s6rCPlio0qgS7otQUjJFh1INqshOOczLGTP/7Fh/STlWk 1mAKuEEpc94RqhzzDUzngstDlVaPPJLTzZ475xreZyPnAqVmUFjjbFsi+qTHMEv8deFoyv8B U9rasrCAvU97IgE21z+NJYpR1tWv/ySzNk1E6sijYGbnYLwZd7ng9MV+hAAAAAAAAA== --------------ms030603000202020303050608--