From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f169.google.com ([209.85.213.169]:32770 "EHLO mail-ig0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753504AbbHZMD6 (ORCPT ); Wed, 26 Aug 2015 08:03:58 -0400 Received: by igfj19 with SMTP id j19so34983627igf.0 for ; Wed, 26 Aug 2015 05:03:57 -0700 (PDT) Subject: Re: Understanding BTRFS storage To: Roman Mamedov , George Duffield References: <20150826165024.05af044f@natsu> Cc: linux-btrfs@vger.kernel.org From: Austin S Hemmelgarn Message-ID: <55DDAB1C.90406@gmail.com> Date: Wed, 26 Aug 2015 08:03:40 -0400 MIME-Version: 1.0 In-Reply-To: <20150826165024.05af044f@natsu> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-512; boundary="------------ms080806060801040603010009" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms080806060801040603010009 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-08-26 07:50, Roman Mamedov wrote: > On Wed, 26 Aug 2015 10:56:03 +0200 > George Duffield wrote: > >> I'm looking to switch from a 5x3TB mdadm raid5 array to a Btrfs based >> solution that will involve duplicating a data store on a second >> machine for backup purposes (the machine is only powered up for >> backups). > > What do you want to achieve by switching? As Btrfs RAID5/6 is not safe = yet, do > you also plan to migrate to RAID10, losing in storage efficiency? > > Why not use Btrfs in single-device mode on top of your mdadm RAID5/6? C= an even > migrate without moving any data if you currently use Ext4, as it can be= > converted to Btrfs in-place. > As of right now, btrfs-convert does not work reliably or safely. I=20 would strongly advise against using it unless you are trying to help get = it working again. --------------ms080806060801040603010009 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 Brgwgga0MIIEnKADAgECAgMQblUwDQYJKoZIhvcNAQENBQAweTEQMA4GA1UEChMHUm9vdCBD QTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNp Z25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcwHhcN MTUwMzI1MTkzNDM4WhcNMTUwOTIxMTkzNDM4WjBjMRgwFgYDVQQDEw9DQWNlcnQgV29UIFVz 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 b20wDQYJKoZIhvcNAQENBQADggIBABr5e8W+NiTER+Q/7wiA2LxWN3UdhT3eZJjqqSlP370P KL5iWqeTfxQ67Ai/mHbJcT2PgAJ+/D2Ji+aRR03UWnU/vtOwzyDLUMstqnfl0Zs+sz/CJe7x nBA5jlpjC2DKuMVfbPze7eySaen7XSGFHKE1QoVIIpQ2kVjC4nbbJQnUbAVX1Iz29WxeVGt9 XYigz3tDPf3tglN+q23E7YjQl4abTIoM7i98yV1H9gfY8lFfKZ6jREB9+n6ie2EwS3Kat2mG tl2wBx4MfRnoSQSKsLKQ5oTwhWf0JqlFwpLfl374p0Njcykej9/jnWG8Ks1V/AXTHqI4eyIP Mf5yMZkPv7n7LS9WWKdG4Nd38iv4T2EiAaWsmgu+r81qL5CJu9AyA0SBS4ttKf6k3e63w2Mv N9R45vpQ3QhAhfWyFxFhZN95APe3YECDG3+XIRJpRYPEtHuIsOyzI70ajF93gg/BidvqKsmV MM2ccktDMfqwZXea6zey7F8Geu9R7BqjXmG2HlNuXu7e/xnHOgXf5D3wPmnRLlBhXL1Ch97a w2KjaupjpAHfFjv5kGnZXN87UvvlwzIZiKXwa3vTDwK+rrKn/sHPkfDZPSiyt/ZBIK6lX83P 34H/CzGg+Kx57rHYOIHGumIvpDa5vfWp8O0sGgawb1C2Aae4sTUVIWmIjVuGI062MYIE0TCC BM0CAQEwgYAweTEQMA4GA1UEChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNl cnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcN AQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxBuVTANBglghkgBZQMEAgMFAKCCAiEwGAYJKoZI hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUwODI2MTIwMzQwWjBPBgkq hkiG9w0BCQQxQgRAEaWgezUHjU/AZ9TAYgVaaha+Gwp85waovy+LXOVUUUDVJ7k1OGgPqV4X 5iralXV29UILQmJTvRopE0NKKD/BEzBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxBuVTCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxBuVTAN BgkqhkiG9w0BAQEFAASCAgCOSyBHIkqUdSytmcjHPiwF0gve4Y3qnMUNWYk4xyUh/6avUYMq 4tSZfDp9ROIrasg3Mk6D6Gb1hPoca3zm5Kq72P7psNuh49mUQIUF96qRKPESkCRdXNFuEWed d0uFqHMiaIzCBZtGYXDxugbIy6oKpEstkKZN7HTFYccV8OZBMjpuYxJU2KJ4o/7V72xMtjXH hCrXRKouOzC+JJxRljwAerLAI9NdlzXkMsdViy7PGKbJ6VTtGKB9mg9UsWoFoJl6TUL3T205 K3pXWTEQnFs+9JkL8XwNgJD5jrJ7jmblyTYg6JRuh3RVXB7qNh+K4UH5/ZxG5LeOlQSc771k DTGyJplq+4tuiCKQTcI8evG6MxfFqzQSZzRyygzjIcQjPKYx6Me1OBKg40tA7csvU6Jw5rg8 xxyJfn22BIpu1CVz4UbtEjmWBJEhIwDIxNwPFdw4pSY94VFzdadgkHSowQksQ+refmLbc89h xMQUneAAbOUyhuQv465jAR4Vb2hV1KHvQ63QO17xgOTh1XVZVutAIe+MgO2exdorOYgY2imd aA9rnnfoaAqjO1Qz8m/5R73f7uGph6jQZsbUQySblYzwGi2kwRu+FHld53t4gfRQ5gbUrW1y h0lSGuQKAPJyyeF0NVkSb9+7ARfOszuMC1xTOXM0SfJ9mw06Vw+6259EEQAAAAAAAA== --------------ms080806060801040603010009--