From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io0-f180.google.com ([209.85.223.180]:33189 "EHLO mail-io0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751650AbbKLOiM (ORCPT ); Thu, 12 Nov 2015 09:38:12 -0500 Received: by iouu10 with SMTP id u10so58802685iou.0 for ; Thu, 12 Nov 2015 06:38:11 -0800 (PST) Subject: Re: Ideas for btrfs-convert fix(or rework) To: Roman Mamedov References: <56418E5D.9020604@gmx.com> <20151110125501.1aa6f155@natsu> <5641A7DA.6010102@gmx.com> <20151110140855.3ae7297c@natsu> <5641B64A.9020606@gmx.com> <564493D5.2070609@gmail.com> <20151112190918.3820dd2a@natsu> Cc: Vytautas D , Btrfs BTRFS From: Austin S Hemmelgarn Message-ID: <5644A44B.6050804@gmail.com> Date: Thu, 12 Nov 2015 09:38:03 -0500 MIME-Version: 1.0 In-Reply-To: <20151112190918.3820dd2a@natsu> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-512; boundary="------------ms060004090805020308060004" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms060004090805020308060004 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-11-12 09:09, Roman Mamedov wrote: > On Thu, 12 Nov 2015 08:27:49 -0500 > Austin S Hemmelgarn wrote: > >> know of (Arch and Gentoo), because the very fact that you installed a >> system with either one means that you are fully capable of backing up >> your data, and reprovisioning the system using BTRFS instead of whatev= er >> filesystem you are already using > > Uhm, what?... How does the fact that I use one particular distro or ano= ther, > reflect on my ability to (easily) back up and restore my 10 TB storage = array? > "You should maintain backups anyway so you could easily restore" -- yea= h I do, > and they are in a remote location over a relatively slow link. I did not mean to imply that you had the ability to do it quickly, just=20 the ability to do it. I specifically stated 'very little' instead of=20 'none' to account for cases like yours. However, the statement is still = accurate because Arch and Gentoo both have very low-level user=20 involvement in the install process (no GUI, user manually provisions the = storage and handles installing the base system). If you are capable of=20 installing such a system (and as such, capable of correctly using stuff=20 like parted or fdisk without breaking anything), you are absolutely=20 capable of reprovisioning such a system (how long that would take is a=20 completely different matter). > I chose Ext4 instead of the other options which seemed more attractive > (primarily XFS, but also JFS) for this array back when creating it a lo= ng time > ago, when Btrfs was still in its much earlier days than now, **SPECIFIC= ALLY** > with the intent to use btrfs-convert "as soon as Btrfs somewhat matures= ". So > as time went, it did, I acted on this plan, and everything went just pe= rfectly. And you got somewhat lucky in that case (and actually did proper=20 research, sadly most people don't seem to do anywhere near enough=20 research when it comes to stuff like this). Doing an in-place=20 conversion of a filesystem (or an OS, or anything else for that matter)=20 is _always_ going to be inherently more risk than just properly=20 reprovisioning (take a look at the absolute insanity that is the 'free'=20 Windows 10 upgrade for an example of this on the OS side). Admittedly,=20 compared to other software that does this (the only other program that I = know of to do this is fstransform), btrfs-convert is relatively safe,=20 but it is not possible for it to be any safer than just reprovisioning. > Why are people so quick to project "If I don't need this, nobody likely= does". > Btrfs-convert is an amazing feature and it will be extremely sad if it = ever > goes away. And as time goes on, it will be used less and less, and it's _always_=20 going to be something that 99% of users who actually use it (if you're=20 doing any kind of RAID, it makes more sense from a data safety=20 perspective to just reprovision so you can use BTRFS's native raid=20 functionality) run exactly once per filesystem per system (once you've=20 converted existing systems, you don't need it unless you were using dump = for backups). I'm not arguing that it should just go away, I'm trying=20 to argue that it shouldn't be a development priority if it works correctl= y. --------------ms060004090805020308060004 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 hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUxMTEyMTQzODAzWjBPBgkq hkiG9w0BCQQxQgRADuUsI5xDU/4hluuwWaiv+lIeJm0bj7ecSrI++0vVJzuEKlySKGtRiMOi Ti5/xVevENeNpVsfmmjSyQIoq3XrLTBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxEt+DCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DAN BgkqhkiG9w0BAQEFAASCAgB8YreP/wBl/oyp1tBZWrkHxtDvODz8MuZn0zzR7vhR9DJadfaB MLdy+HFCcb7iE7ZtwGlLBzsUtOhUBMzAMZn3PHImv6QCYb6aWvl4tdcNlPWQjAnkSc6GNdnS z6wv50DK+WdvG5fivMwS1Uue4hcz5dUHxjk/8E7qZSbMJ4eoul2FZ7t4gpEolJtmFlO74AKh m7Q59o0QEWZ2X43WVWuJx1RBBTrphmXNlhIWai//jFaR8AtjpTivbmNZUPFN+s+rlaU3mtQl U82Ne/Z0q3pMRdj2MDZ4/ZnHIKq4WS37BlC7JGYijvjC6YpRGxgLh1F0drzfmOxka3RfXRN7 mzKmP/6eY+4gHgUSnKxqZP9Tbf7it9/LbaUciCGCav8FiUmY1YkWxvwDOwGSJOqKhoVbHdrp DKqCwvqY2ZzkDrfi8s/iQZls8s7bSro7ywiH+dFDhrnmNrkahm5qnDoSKlmNV2w4QTTF6D1Q /wh04nmwt8fqBGujLWj0o5RAbJxnKp+Wzatv69OBG0HOA2InUOA0Opdw1gExWB5VRcultw2M WcUb6kdr3JV3nTgLHvCRmn3ZKrb4rcvVGY2FOguDbzYwh329XPBwT9LCvk76OlDStTUFyZo8 7yxlpnXAi+TLiNKlU4xfzbGOw8iwzomrcCW+v44wEwje1eTbz3HZCHr8cAAAAAAAAA== --------------ms060004090805020308060004--