From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f178.google.com ([209.85.213.178]:41152 "EHLO mail-ig0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753528AbaFSLQF (ORCPT ); Thu, 19 Jun 2014 07:16:05 -0400 Received: by mail-ig0-f178.google.com with SMTP id hn18so1846707igb.5 for ; Thu, 19 Jun 2014 04:16:04 -0700 (PDT) Message-ID: <53A2C651.5080907@gmail.com> Date: Thu, 19 Jun 2014 07:15:29 -0400 From: Austin S Hemmelgarn MIME-Version: 1.0 To: Chris Murphy , Btrfs BTRFS , =?UTF-8?B?RGFuaWVsIENlZ2llxYJrYQ==?= Subject: Re: btrfs on whole disk (no partitions) References: <33D49915-811C-459F-B221-3F342F6D4944@colorremedies.com> In-Reply-To: <33D49915-811C-459F-B221-3F342F6D4944@colorremedies.com> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms090605060905000403010005" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms090605060905000403010005 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable On 2014-06-18 16:10, Chris Murphy wrote: >=20 > On Jun 18, 2014, at 1:29 PM, Daniel Cegie=C5=82ka wrote: >=20 >> Hi, >> I created btrfs directly to disk using such a scheme (no partitions): >> >> dd if=3D/dev/zero of=3D/dev/sda bs=3D4096 >> mkfs.btrfs -L dev_sda /dev/sda >> mount /dev/sda /mnt >> >> cd /mnt >> btrfs subvolume create __active >> btrfs subvolume create __active/rootvol >> btrfs subvolume create __active/usr >> btrfs subvolume create __active/home >> btrfs subvolume create __active/var >> btrfs subvolume create __snapshots >> >> cd / >> umount /mnt >> mount -o subvol=3D__active/rootvol /dev/sda /mnt >> mkdir /mnt/{usr,home,var} >> mount -o subvol=3D__active/usr /dev/sda /mnt/usr >> mount -o subvol=3D__active/home /dev/sda /mnt/home >> mount -o subvol=3D__active/var /dev/sda /mnt/var >> >> # /etc/fstab >> UID=3DID / btrfs rw,relative,space_cache,subvol=3D__active/rootv= ol 0 0 >> UUID=3DID /usr btrfs rw,relative,space_cache,subvol=3D__active/u= sr 0 0 >> UUID=3DID /home btrfs rw,relative,space_cache,subvol=3D__active/= home 0 0 >> UUID=3DID /var btrfs rw,relative,space_cache,subvol=3D__active/v= ar 0 0 >=20 > rw and space_cache are redundant because they are default; and relative= is not a valid mount option. All you need is subvol=3D=20 >=20 >> Everything works fine. Is such a solution is recommended? In my >> opinion, the creation of the partitions seems to be completely >> unnecessary if you can use btrfs. >=20 > It's firmware specific. Some BIOS firmwares will want to see a valid MB= R partition map at LBA 0, not just boot code. Others only care to blindly= execute the boot code which would be put in the Btrfs bootloader pad (64= KB). I don't know if parted 3.1 recognizes partitionless disks with Btrfs= though so it might slightly increase the risk that it's treated as somet= hing other than what it is. >=20 > For UEFI firmware, it would definitely need to be partitioned since an = EFI System partition is required. >=20 > Chris Murphy-- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" = in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html >=20 On most hardware, I would definitely suggest at least adding a minimal sized partition table, the people who design the BIOS code on most systems make too many assumptions to trust their code to work correctly. That said, I regularly use BTRFS on flat devices for the root filesystems for Xen PV Guest systems, systems that boot from SAN, and secondary disks on other systems with no issues whatsoever. --------------ms090605060905000403010005 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 BrQwggScoAMCAQICAw8BRDANBgkqhkiG9w0BAQ0FADB5MRAwDgYDVQQKEwdSb290IENBMR4w HAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmlu ZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZzAeFw0xNDA1 MTIxNDEwMzJaFw0xNDExMDgxNDEwMzJaMGMxGDAWBgNVBAMTD0NBY2VydCBXb1QgVXNlcjEj MCEGCSqGSIb3DQEJARYUYWhmZXJyb2luN0BnbWFpbC5jb20xIjAgBgkqhkiG9w0BCQEWE2Fo ZW1tZWxnQG9oaW9ndC5jb20wggIiMA0GCSqGSIb3DQEBAQUAA4ICDwAwggIKAoICAQDbLUaL Gs4JTdU7sgr0MzD57CMUAv307ddC9pxooDMN3PiUvzEd5kLtBCh8KDB1wbMdfm4hte2rDd+j hM1tIq67BvNbdDPztOcBZwT2/3OVyyG4B1ddCqUyt03zGKw6Y34eHNfapsZiiItX0GBNfjHU Wv+WDo+XNha/WmGSSMv21HkftF9XA1KC9Bpr9JJI23MKK7T2g/7b3KoGZlx3ekLIJsF5B7+B DMPPDqOHQbRnccyOHEMyhM13g6WoAbU+3aKYc+C/9UsYtDV+xlvBLWagky1acstD5wOA35V6 uDRbUhD+vOjuMRMCj9jJOIYqa6AeSagBjxRnisJr0RFzQ4f+NjGCHPaFTvRvbkiXh4q22doT 0SxbNBUm7B9ANugIOtS9/VQhTWKDi//WTqZQ7Ecl4yVJbMCUg/iaRHMCGS41vqMICPszRidW rL04NwS9D2cREEY1y/xrNo0ZvKPZu6tLhxhPf7w+5rsN3+wWxGaR1hNpnVUT9AeacLKZO6W9 FsRT3Unkr91IhQATHTKYr4EAkjN/5lgvA+sxp5TxxsUnoJYrD8IHf8aYfJsAHMleBwx4xSeZ tw/n5iIjJjFZq9IRZ1zQhK62p+a5vJ2vlJHjTgavhQrfb1pUOjbqsnI4ndQ5hNosL9el4Kxq Yko+HsxVEmSwSsjq6cV2L3oz0z8NUwIDAQABo4IBWTCCAVUwDAYDVR0TAQH/BAIwADBWBglg hkgBhvhCAQ0ESRZHVG8gZ2V0IHlvdXIgb3duIGNlcnRpZmljYXRlIGZvciBGUkVFIGhlYWQg b3ZlciB0byBodHRwOi8vd3d3LkNBY2VydC5vcmcwDgYDVR0PAQH/BAQDAgOoMEAGA1UdJQQ5 MDcGCCsGAQUFBwMEBggrBgEFBQcDAgYKKwYBBAGCNwoDBAYKKwYBBAGCNwoDAwYJYIZIAYb4 QgQBMDIGCCsGAQUFBwEBBCYwJDAiBggrBgEFBQcwAYYWaHR0cDovL29jc3AuY2FjZXJ0Lm9y ZzAxBgNVHR8EKjAoMCagJKAihiBodHRwOi8vY3JsLmNhY2VydC5vcmcvcmV2b2tlLmNybDA0 BgNVHREELTArgRRhaGZlcnJvaW43QGdtYWlsLmNvbYETYWhlbW1lbGdAb2hpb2d0LmNvbTAN BgkqhkiG9w0BAQ0FAAOCAgEAIokFPcW8+cO2Clu0Ei+ehAmQRBHfV5RWJ8aMVLXOCfiJX0ch IjVSIt6I3uQaR4J1ZIAjCSPkbpfZQDaLoGFI5j8aYEQhOeKxrvOMzY9/aSUYabCJIhE/sX64 klFV0bzm+PR9cDMWeQ9BoZf0m8UROPSfDnrjEk+p04hGg3pAZMcSwCzxdb604NHjgHJmf2xG UQVzQgC6Ek/BKat0xuPTuPmtPv9OicK75CPmLZKYW3rFpCD6bhb1mm+ROcCNhniRY2LYm9YN QdlHQUzTFqj0tvuYrzNI3LNV4PjEfN8z6omPCT2Rq8/uKLseN+m8F0ioqm+cphqpmzKoDUpN nePLkqDFUFWCeWRxSjBTy4IMVUfdNXriVGihH8hyIICQiOfmmBOzhzUifdomJuTGtoXRuHVT R2f/YdrJrLnKI4f+Othdp7F3KhB4c6JiOnTEH5J8n9q3rFjt4MPRwcjIHMhmF5nZVQlgxEMo 1cPCmvG1D9tcgXbH79jjqydo9SDXhzLQob7axkzGRY96IstNcvoQ/UNsdPPfFMYlHtGz4TxT DhBjv4ERskGmKBZrfmxkXkcuTV/gcykct6Xvw9YXb8WTL4qSYHSYk9fReVLgE/L4RBUpX2JJ QvIR0AJLER165/aZlQXZtuJjnfxJtJTJZZ+Gor9h0G2kuR5Dy0JuYdBO4t4xggShMIIEnQIB ATCBgDB5MRAwDgYDVQQKEwdSb290IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5v cmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEW EnN1cHBvcnRAY2FjZXJ0Lm9yZwIDDwFEMAkGBSsOAwIaBQCgggH1MBgGCSqGSIb3DQEJAzEL BgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTE0MDYxOTExMTUyOVowIwYJKoZIhvcNAQkE MRYEFCrAKmtUcAfvaKWmxfp/MRKK04dPMGwGCSqGSIb3DQEJDzFfMF0wCwYJYIZIAWUDBAEq MAsGCWCGSAFlAwQBAjAKBggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwIC AUAwBwYFKw4DAgcwDQYIKoZIhvcNAwICASgwgZEGCSsGAQQBgjcQBDGBgzCBgDB5MRAwDgYD VQQKEwdSb290IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMT GUNBIENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2Fj ZXJ0Lm9yZwIDDwFEMIGTBgsqhkiG9w0BCRACCzGBg6CBgDB5MRAwDgYDVQQKEwdSb290IENB MR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2ln bmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZwIDDwFE MA0GCSqGSIb3DQEBAQUABIICADnKhzE91gBIPAc34Oy+z5lp+zAjAbjWORanYHndnFn6Dl6r DHfZldIys9wrIHrx8CRpQJRGSkuuVmgo1c0CtaErVTFElUOciCiu4EBxlWEKJeW5ch5QqMo5 yDYGlxas3JV3Pzp53PTK9EaQHW9FHIw8bYlf/5CE4Q1DZvkTta5YmHl0yDgMl5XmGBaf8+P6 gk3r+x6u2W6zHYkPYjrY4AtshIfoJTCZSOAww5t5RBlpxZj1TXZTyohR+zWFTfyGAiXy5y1e M6UnTV1o7hJsjAfzsQ7VmEVmaArv0AdsI/UoYQjBqGf3wyNckJupkdG1beZXbUywmZFiyfmH IhyM8nPIKBFMmoyu4U+rH4qrc63SnQtFUc32eZ44j6o678j7Bpc0FVcthdE6THPiLQmJsoCV ISeUHZgLxSKrkexQEa5iBz44v5T6r8xxmd4BzvGyvYKsO7Q2fo1kqI3V/1P3r2ca4/xogs/S 55YM9Kpy6odbYTIq78uCWSQdGwAE7RoKV8Tq6uOuNeCZgbbpcO1H5a+ozCFTpxX5E2lLZV0D FCfm2OwskrW+5psvy2hVZSXEz2s0FChHL4bQTtQ6sddkXnBi1XGQfrAbbqHFH3tN7mc+rGsV kjYrV39r6ilQVfGmVxN7fdcmubYgp6pYWY6qFXm9HiMvCKlp4PWMp6Kgv1/kAAAAAAAA --------------ms090605060905000403010005--