From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f181.google.com ([209.85.213.181]:35440 "EHLO mail-ig0-f181.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752619AbbD0LrF (ORCPT ); Mon, 27 Apr 2015 07:47:05 -0400 Received: by igbyr2 with SMTP id yr2so60010257igb.0 for ; Mon, 27 Apr 2015 04:47:05 -0700 (PDT) Message-ID: <553E21B7.2030808@gmail.com> Date: Mon, 27 Apr 2015 07:47:03 -0400 From: Austin S Hemmelgarn MIME-Version: 1.0 To: "Lentes, Bernd" , "'linux-btrfs@vger.kernel.org'" Subject: Re: rollback of a snapshot is just read-only References: <15785B7E063D464C86DD482FCAE4EBA501CAC3EF69DB@XCH11.scidom.de> In-Reply-To: <15785B7E063D464C86DD482FCAE4EBA501CAC3EF69DB@XCH11.scidom.de> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms080400030404060207010308" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms080400030404060207010308 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-04-24 10:26, Lentes, Bernd wrote: > Hi, > > it should be just a small problem, but it is one. How can I rollback to= a snapshot of my root filesystem ? > Googeling, I found a lot of solutions, each different. > I finally choosed this one: https://btrfs.wiki.kernel.org/index.php/Use= Cases#I_want_to_be_able_to_do_rollbacks_with_Btrfs > > I made the snapshot, changed some configuration, and afterwards I'd lik= e to rollback to the snapshot: > > - btrfs subvolume snapshot -r / /.snapshots/vor_nvidia > > - change some configuration > > - btrfs subvolume set-default 625 (id of the snapshot) > > - reboot > > My /-folder is again the old one, that's ok. The change of the configur= ation has disappeared. But it is just read-only: > pc63422:~ # touch /test > touch: cannot touch '/test': Read-only file system > > mount says: > > ... > /dev/sda1 on / type btrfs (rw,ssd,space_cache) > ... > > It seems to be rw !? > > OS: SLES 12 64bit > kernel: 3.12.38-44-default > > pc63422:~ # rpm -qa|grep -i btrfs > btrfsprogs-3.16.2-7.1.x86_64 > libbtrfs0-3.16.2-7.1.x86_64 > btrfsmaintenance-0.1-7.1.noarch > > pc63422:~ # btrfs --version > Btrfs v3.16.2+20150127 > > pc63422:~ # btrfs fi show > Label: none uuid: 7edcb64a-4ca6-47ec-8979-54e158c96ac2 > Total devices 1 FS bytes used 145.19GiB > devid 1 size 450.00GiB used 150.04GiB path /dev/sda1 > > pc63422:~ # btrfs fi df / > Data, single: total=3D146.01GiB, used=3D142.74GiB > System, single: total=3D32.00MiB, used=3D16.00KiB > Metadata, single: total=3D4.00GiB, used=3D2.44GiB > GlobalReserve, single: total=3D512.00MiB, used=3D0.00B > > Thanks for any hint. > > So, a snapshot being read-only is totally different from the FS being=20 mounted read-only. There is a special property on the snapshot that=20 determines whether it is read-only or writable, which is first set when=20 the snapshot is created. To change that property so that the snapshot=20 is writable, you can use the following command from the top directory of = the snapshot: btrfs property set . ro false --------------ms080400030404060207010308 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIGuDCC BrQwggScoAMCAQICAxBuVTANBgkqhkiG9w0BAQ0FADB5MRAwDgYDVQQKEwdSb290IENBMR4w HAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmlu ZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZzAeFw0xNTAz MjUxOTM0MzhaFw0xNTA5MjExOTM0MzhaMGMxGDAWBgNVBAMTD0NBY2VydCBXb1QgVXNlcjEj MCEGCSqGSIb3DQEJARYUYWhmZXJyb2luN0BnbWFpbC5jb20xIjAgBgkqhkiG9w0BCQEWE2Fo ZW1tZWxnQG9oaW9ndC5jb20wggIiMA0GCSqGSIb3DQEBAQUAA4ICDwAwggIKAoICAQCdD/zW 2rRAFCLnDfXpWxU1+ODqRVUgzHvrRO7ADUxRo1CBDc3JSX5TIW2OGmQ3DAKGOACp8Z0sgxMc B05tzAZ/M7m4jajVrwwdVCdrwVGxTdAai7Kwg4ZCVfyMVhcwo8R2eW3QahBx34G0RKumK9sZ ZQSQ+zULAzpY6uz7T1sAk/erMoivRXF6u8WvOsLkOD1F/Xyv1ZccSUG5YeDgZgc0nZUBvyIp zXSHjgWerFkrxEM3y2z/Ff3eL1sgGYecV/I1F+I5S01V7Kclt/qRW10c/4JEGRcI1FmrJBPu BtMYPbg/3Y9LZROYN+mVIFxZxOfrmjfFZ96xt/TaMXo8vcEKtWcNEjhGBjEbfMUEm4aq8ygQ 4MuEcpJc8DJCHBkg2KBk13DkbU2qNepTD6Uip1C+g+KMr0nd6KOJqSH27ZuNY4xqV4hIxFHp ex0zY7mq6fV2o6sKBGQzRdI20FDYmNjsLJwjH6qJ8laxFphZnPRpBThmu0AjuBWE72GnI1oA aO+bs92MQGJernt7hByCnDO82W/ykbVz+Ge3Sax8NY0m2Xdvp6WFDY/PjD9CdaJ9nwQGsUSa N54lrZ2qMTeCI9Vauwf6U69BA42xgk65VvxvTNqji+tZ4aZbarZ7el2/QDHOb/rRwlCFplS/ z4l1f1nOrE6bnDl5RBJyW3zi74P6GwIDAQABo4IBWTCCAVUwDAYDVR0TAQH/BAIwADBWBglg hkgBhvhCAQ0ESRZHVG8gZ2V0IHlvdXIgb3duIGNlcnRpZmljYXRlIGZvciBGUkVFIGhlYWQg b3ZlciB0byBodHRwOi8vd3d3LkNBY2VydC5vcmcwDgYDVR0PAQH/BAQDAgOoMEAGA1UdJQQ5 MDcGCCsGAQUFBwMEBggrBgEFBQcDAgYKKwYBBAGCNwoDBAYKKwYBBAGCNwoDAwYJYIZIAYb4 QgQBMDIGCCsGAQUFBwEBBCYwJDAiBggrBgEFBQcwAYYWaHR0cDovL29jc3AuY2FjZXJ0Lm9y ZzAxBgNVHR8EKjAoMCagJKAihiBodHRwOi8vY3JsLmNhY2VydC5vcmcvcmV2b2tlLmNybDA0 BgNVHREELTArgRRhaGZlcnJvaW43QGdtYWlsLmNvbYETYWhlbW1lbGdAb2hpb2d0LmNvbTAN BgkqhkiG9w0BAQ0FAAOCAgEAGvl7xb42JMRH5D/vCIDYvFY3dR2FPd5kmOqpKU/fvQ8ovmJa p5N/FDrsCL+YdslxPY+AAn78PYmL5pFHTdRadT++07DPIMtQyy2qd+XRmz6zP8Il7vGcEDmO WmMLYMq4xV9s/N7t7JJp6ftdIYUcoTVChUgilDaRWMLidtslCdRsBVfUjPb1bF5Ua31diKDP e0M9/e2CU36rbcTtiNCXhptMigzuL3zJXUf2B9jyUV8pnqNEQH36fqJ7YTBLcpq3aYa2XbAH Hgx9GehJBIqwspDmhPCFZ/QmqUXCkt+XfvinQ2NzKR6P3+OdYbwqzVX8BdMeojh7Ig8x/nIx mQ+/ufstL1ZYp0bg13fyK/hPYSIBpayaC76vzWovkIm70DIDRIFLi20p/qTd7rfDYy831Hjm +lDdCECF9bIXEWFk33kA97dgQIMbf5chEmlFg8S0e4iw7LMjvRqMX3eCD8GJ2+oqyZUwzZxy S0Mx+rBld5rrN7LsXwZ671HsGqNeYbYeU25e7t7/Gcc6Bd/kPfA+adEuUGFcvUKH3trDYqNq 6mOkAd8WO/mQadlc3ztS++XDMhmIpfBre9MPAr6usqf+wc+R8Nk9KLK39kEgrqVfzc/fgf8L MaD4rHnusdg4gca6Yi+kNrm99anw7SwaBrBvULYBp7ixNRUhaYiNW4YjTrYxggShMIIEnQIB ATCBgDB5MRAwDgYDVQQKEwdSb290IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5v cmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEW EnN1cHBvcnRAY2FjZXJ0Lm9yZwIDEG5VMAkGBSsOAwIaBQCgggH1MBgGCSqGSIb3DQEJAzEL BgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTE1MDQyNzExNDcwM1owIwYJKoZIhvcNAQkE MRYEFBeBw0txQlo/sYfEiT6TLa7Q+BFJMGwGCSqGSIb3DQEJDzFfMF0wCwYJYIZIAWUDBAEq MAsGCWCGSAFlAwQBAjAKBggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwIC AUAwBwYFKw4DAgcwDQYIKoZIhvcNAwICASgwgZEGCSsGAQQBgjcQBDGBgzCBgDB5MRAwDgYD VQQKEwdSb290IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMT GUNBIENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2Fj ZXJ0Lm9yZwIDEG5VMIGTBgsqhkiG9w0BCRACCzGBg6CBgDB5MRAwDgYDVQQKEwdSb290IENB MR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2ln bmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZwIDEG5V MA0GCSqGSIb3DQEBAQUABIICAEY2gmywC7S5ZJnLyb+OCD624ynn3ov8Q7XDEphhTniZ0pjw xd3XoMUGfgi6h8ZELJnP3RaIyQziCxHmVLp2tc5AXfW82pHI9k/1yeCCRVsXvF/tcxUaEC+/ nWmplNNRQYePuqmzaRr2kwynHReO7bkfu+W6j1upxruWXqW+2T06wFOQaTPXDRvV6vJjg89p 2P+BycJdqnN0/BzDYePTMJ847xGJgc9KdTU52rG5DGxZ19uFw/8+3NcwvS/CFQWVhK59CoGo BEqMxY61fMkzXZ3/PvxXnr+8k9dnUKRTt/HD+Bib8j3caLWY6jK14dPdDbSpHfmPAffzp+32 JeZoi2Tik2A3cL1uvhCX3G6i/Xy5H9SVxGtIunHkCjK+oRohTLZtt5L+LjBFzYv5opBm82yk YA9weTBoMxZzB7s1oGGHkt/Fewejdxg16ZVEqKU9Dsx6XIlFkGvGu8vJi6X17ZAdQxePOdJD Y62wsOniMrRqSMF8RHlbPWCIByMiNjjN7h7FsFfwNFSEGP1kNSZmuahli6Q+90jmeDQOnqIj gnPY7qqAt5ziQZ24iOo2T2CgGbdgKcCEaMUhM0Mg6PowzUeiFf1kGeF4UlfR/5lYioF9vPOL 0YTn4frOJjNJBJstgZY7NyQZkco4qarPWF7IMoVBNmxDcbPQ/ziwlbXyiyLxAAAAAAAA --------------ms080400030404060207010308--