From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f169.google.com ([209.85.213.169]:34224 "EHLO mail-ig0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753387AbbLITEN (ORCPT ); Wed, 9 Dec 2015 14:04:13 -0500 Received: by igvg19 with SMTP id g19so130819803igv.1 for ; Wed, 09 Dec 2015 11:04:13 -0800 (PST) Subject: Re: subvols and parents - how? To: Duncan <1i5t5.duncan@cox.net>, linux-btrfs@vger.kernel.org References: <1448340960.14125.51.camel@scientia.net> <1448400350.21291.88.camel@scientia.net> <1449635797.20578.0.camel@scientia.net> From: Austin S Hemmelgarn Message-ID: <56687B26.7070300@gmail.com> Date: Wed, 9 Dec 2015 14:04:06 -0500 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-512; boundary="------------ms050403030004050101080509" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms050403030004050101080509 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable On 2015-12-09 05:53, Duncan wrote: > Christoph Anton Mitterer posted on Wed, 09 Dec 2015 05:36:37 +0100 as > excerpted: >=20 >> On Fri, 2015-11-27 at 01:02 +0000, Duncan wrote: >> [snip snap] >>> #2 The point I was trying to make, now, to mount it you'll mount not = a >>> native nested subvol, and not a directly available sibling >>> 5/subvols/home, but you'll actually be reaching into an entirely >>> different nesting structure to grab something down inside, mounting >>> 5/subvols/root/home subvolume nesting down inside the direct >>> 5/subvols/root sibling subvol. >> >> Okay so your main point was basically "keeping things administrable"..= =2E >=20 > =3D:^) >=20 >>> one of which was that everything that the package manager installs >>> should be on the same partition with the installed-package database, = so >>> if it has to be restored from backup, at least if it's all old, at >>> least it's all equally old, and the package database actually matches= >>> what's on the system because it's in the same backup! >=20 >> I basically agree, though I'd allow few exceptions, like database-like= >> data that is stored in /var/ sometimes and that doesn't need to be >> consistent with anything but iself... e.g. static web pages >> (/var/www)... postgresl DB, or sks keyserver DB... and so on. >=20 > Of course. But such data isn't usually managed by the package manager,= =20 > so splitting off a partition or subvolume or whatever, is fair game. >=20 > IOW, /var can and should still be on /, but /var/www and the like can b= e=20 > on some other subvolume or filesystem. >=20 Agreed. It's not too bad fixing a Gentoo system (as long as /var/lib/portage/world is still correct, you can just nuke the installed package database and emerge world, it'll take time, but it will get your system in a guaranteed consistent state). On something using dpkg or rpm though, it's got the potential to be almost impossible to recover from without a significant amount of low-level knowledge of the package manager's installation database. --------------ms050403030004050101080509 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 hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUxMjA5MTkwNDA3WjBPBgkq hkiG9w0BCQQxQgRAec4pKG5WZYKSn+XUuyh7WJPAlPyvmtZZ52KBgFXdmFkg8XdvlXOv5ZQt 4tfdAlXr8soot1XMzG5BH7OgAuld2TBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxEt+DCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxEt+DAN BgkqhkiG9w0BAQEFAASCAgA4at8YuHPe/aDiAGOYrytaTmSw1fg+XS9+1f6XgrkwGNOFqAOy jt3bg66DUqJv67cWJLNzu71JLxt9h2w/S4wnQxC616JSGNY3cbmy/k3wmyD7eHtJADL2YJlr Ta/n27YdoZk+LbkeytTDLYH5Oek+KjtQi7o1lnbM18qvyziHECOaH+OJbXU2G6CuquQNgtU4 P+CYp69P9TnuLerHqBzqlzuJZIb1VwCB0FKqOnN7QMbpov0CmH6jeivh1qZQbAdfYFfDOAoL fqgZQFQlHcP9QeKEP48rKatfFQu6t5SuTEeTE5hoAO91pCAulsNWLSsCkV7WGLQ9xw3p3CCM ymMtoztVPsivT6a9lyzMSWT/KpSKAlzjNcmIcmiiYhR1u8ok0kTxHILH/Q1A8/xLnAx9wJde e8ZwSnXJAT77VWLAwXWmoAqgrFSbZYtYgh+yDgj9pNt2XsZQyFCHYnuEFfnCuyW5eglw0Rhn OYhe6JiRkitffrwXfkwLRM4MVo7kndvXHJjrN0TjtGhH/vRJ8IHYNAjmaoPOzhVQpwzTlhV6 qtC9m3iMGz//eC8HfkrjuUxlsoiOO+sBk06jZYxm0Xw29z1o4Wqnx2MGDHrjsdT2RfN9Oru7 Kat/wh0gIB/xxsYnfu2IIdpYTGl6QL65ECcueRGdxBer3wVoThkRnPdt/AAAAAAAAA== --------------ms050403030004050101080509--