From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f177.google.com ([209.85.213.177]:38920 "EHLO mail-ig0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752695AbaFPLYA (ORCPT ); Mon, 16 Jun 2014 07:24:00 -0400 Received: by mail-ig0-f177.google.com with SMTP id l13so2792011iga.16 for ; Mon, 16 Jun 2014 04:23:59 -0700 (PDT) Message-ID: <539ED3A2.50309@gmail.com> Date: Mon, 16 Jun 2014 07:23:14 -0400 From: Austin S Hemmelgarn MIME-Version: 1.0 To: =?ISO-8859-1?Q?Sw=E2mi_Petaramesh?= CC: Linux BTRFS Subject: Re: BTRFS, SSD and single metadata References: <1723493.aXdklhDgAK@vajra> <539ED083.5050705@gmail.com> <4823159.jCObc9Zrv0@vajra> In-Reply-To: <4823159.jCObc9Zrv0@vajra> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms090601010108070607040108" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms090601010108070607040108 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 2014-06-16 07:18, Sw=E2mi Petaramesh wrote: > Hi Austin, and thanks for your reply. >=20 > Le lundi 16 juin 2014, 07:09:55 Austin S Hemmelgarn a =E9crit : >> >> What mkfs.btrfs looks at is >> /sys/block//queue/rotational, if that is 1 it knows >> that the device isn't a SSD. I believe that LVM passes through whatev= er >> the next lower layer's value is, but dmcrypt (and by extension LUKS) >> always force it to a 1 (possibly to prevent programs from using >> heuristics for enabling discard) >=20 > In the current "running condition", the system clearly sees this is *no= t*=20 > rotational, even thru the LVM/dmcrypt stack : >=20 > # mount | grep btrfs > /dev/mapper/VG-LINUX on / type btrfs=20 > (rw,noatime,seclabel,compress=3Dlzo,ssd,discard,space_cache,autodefrag)= >=20 > # ll /dev/mapper/VGV-LINUX > lrwxrwxrwx. 1 root root 7 16 juin 09:21 /dev/mapper/VG-LINUX -> ../dm-= 1 >=20 > # cat /sys/block/dm-1/queue/rotational=20 > 0 >=20 > ...However, at mkfs.btrfs time, it migth well not have seen it, as I ma= de it=20 > from a live USB key in which both the lvm.conf and crypttab had not bee= n=20 > taylored to allow "trim" commands... >=20 > However, now that the FS is created, I still wonder whether I should us= e a=20 > rebalance to change the metadata from DUP to SINGLE, or if Id' better s= tay=20 > with DUP... >=20 > Kind regards. >=20 >=20 I'd personally stay with the DUP profile, but then that's just me being paranoid. You will almost certainly get better performance using the SINGLE profile instead of DUP, but this is mostly due to it requiring fewer blocks to be encrypted by LUKS (Which is almost certainly your primary bottleneck unless you have some high-end crypto-accelerator card)= =2E --------------ms090601010108070607040108 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 BgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8XDTE0MDYxNjExMjMxNFowIwYJKoZIhvcNAQkE MRYEFJCIxlqjr799lOKDTpAudLQEnSQqMGwGCSqGSIb3DQEJDzFfMF0wCwYJYIZIAWUDBAEq MAsGCWCGSAFlAwQBAjAKBggqhkiG9w0DBzAOBggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwIC AUAwBwYFKw4DAgcwDQYIKoZIhvcNAwICASgwgZEGCSsGAQQBgjcQBDGBgzCBgDB5MRAwDgYD VQQKEwdSb290IENBMR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMT GUNBIENlcnQgU2lnbmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2Fj ZXJ0Lm9yZwIDDwFEMIGTBgsqhkiG9w0BCRACCzGBg6CBgDB5MRAwDgYDVQQKEwdSb290IENB MR4wHAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2ln bmluZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZwIDDwFE MA0GCSqGSIb3DQEBAQUABIICAF0cHZqgx7s9wSTgSnanUIZAjvM2WP7BiDaa7upvwmd1Bq81 1mFLjCr3uUYMO/GM3ZYNOYyVqb4DhybCDPGG9OTg0h4pF4kUybgPFveNV9xJ50fif/HDPRBo B1yiFnIvswCka+ng4/bzA5A81P66NVJEQJhKtbxcB0wWDRtD4uESS2sjvqcURT1/5DULSBWd get57FLY3MtSHjPNRGaGUOuLSlOy4XyVIo8kVuNnxYHSTyeGXf6X79Ys4asePBrO9QVqDVX2 baYm185XDsQaG73f16tW5460rLDOY/79gnfWHi384WXDZnduyONrXWwO0sBfcC1UdgI4OhQQ WIpfFq7jg/SJfwJpBoCJjxf4tuBUxfI6tIRI/EpMkBlNP3aCtROqIZUviWZ/bN2PiNiG0Oy5 v/p+T2maWXDiImxG1mBW9iaT9jbV7++CEZM8ulQ30G/1caJzqmfV4OTiH5FTwwmZoFR7Nzyx 0Ed0zzXQIGSbJOQbDFtPK1yUCacaFBdWWTuLFiD/2XUV3u+crJ4z6IhNsNr97Dq/9oFkTl0z krGvkHrnSL5OJlcOxUuIRwaYUcd5FcE5HybeuwXUkA1UiCAQJk2ylVo+irJMFZHnwBlTktFo /WGJqc50ZkAsxucS3YK2Sc444uDmlTX4RrN4oe8GQw01Pk0TxFLtBYo74pNlAAAAAAAA --------------ms090601010108070607040108--