From mboxrd@z Thu Jan 1 00:00:00 1970 From: Peter Kieser Subject: Re: bad bcache performance - crappy SSD? Date: Tue, 27 May 2014 13:13:30 -0700 Message-ID: <5384F1EA.2070402@kieser.ca> References: <20140526221649.GI10209@teapot> Mime-Version: 1.0 Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms050907040901030807070402" Return-path: Received: from mail.pfak.org ([198.50.219.4]:53556 "EHLO mail.pfak.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751936AbaE0UMz (ORCPT ); Tue, 27 May 2014 16:12:55 -0400 In-Reply-To: <20140526221649.GI10209@teapot> Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Matthias Ferdinand , linux-bcache@vger.kernel.org This is a cryptographically signed message in MIME format. --------------ms050907040901030807070402 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable What filesystem are you running on top of bcache? There are issues with=20 XFS and barrier modes causing 100% util on the cache device. -Peter On 2014-05-26 3:16 PM, Matthias Ferdinand wrote: > Hi, > > so far I have been unable to get an actual performance improvement out > of bcache, and I suspect that my SSD is just crap. Any help or hint > appreciated. What (SATA) SSDs have you been using successfully with > bcache? > > > My host system: Ubuntu 14.04 x64. > kernels tried: Ubuntu stock (3.13.0-24), 3.14, 3.15-rc{5,6}. > > storage structure: > 3xSATA (sda,sdb,sdc) =3D> md raid5 (md125) =3D> bcache0 =3D> LVM (dm-1)= > > benchmark: install linux kernel header package inside kvm guest > > cache device not attached: 0:18 minutes > SSD cache device attached (writethrough): 3:27 minutes > SSD cache device attached (writeback): 3:25 minutes > > With attached cache device, the ssd seems very busy (iostat %util), > while the raid members are not: > > Device: rrqm/s wrqm/s r/s w/s rkB/s wkB/s = avgrq-sz avgqu-sz await r_await w_await svctm %util > (5) sdc 0.00 12.33 0.00 57.33 0.00 57.00 = 1.99 0.06 1.07 0.00 1.07 0.79 4.53 > (5) sdb 0.33 12.00 0.33 57.00 2.67 54.33 = 1.99 0.07 1.19 0.00 1.19 0.84 4.80 > (5) sda 0.00 11.33 0.00 57.00 0.00 51.67 = 1.81 0.06 1.10 0.00 1.10 0.80 4.53 > (*) sdf 0.00 0.00 0.00 54.67 0.00 27.17 = 0.99 0.98 18.05 0.00 18.05 17.95 98.13 > > (5) raid 5 member; (*) SSD > > > when I replace the SSD with a single SATA disk: > SATA cache device attached (writethrough): 0:19 minutes > SATA cache device attached (writeback): 0:13 minutes > > > The SSD is an Intel 530, has current firmware and plenty of DISCARDed > blocks. Specs claim >=3D 13.000 incompressible writes/sec for the 120G= B > model, but the above data suggests it can handle just about 60. > > > =3D=3D=3D START OF INFORMATION SECTION =3D=3D=3D > Device Model: INTEL SSDSC2BW120A4 > Serial Number: CVDA3393028N1207GN > LU WWN Device Id: 5 5cd2e4 04b82aa5a > Firmware Version: DC32 > User Capacity: 120,034,123,776 bytes [120 GB] > Sector Size: 512 bytes logical/physical > Rotation Rate: Solid State Device > Device is: Not in smartctl database [for details use: -P sh= owall] > ATA Version is: ACS-2 (minor revision not indicated) > SATA Version is: SATA 3.0, 6.0 Gb/s (current: 3.0 Gb/s) > Local Time is: Sat May 24 20:37:14 2014 CEST > SMART support is: Available - device has SMART capability. > SMART support is: Enabled > > > > Regards > Matthias > -- > To unsubscribe from this list: send the line "unsubscribe linux-bcache"= in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --------------ms050907040901030807070402 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIINgDCC BjQwggQcoAMCAQICASAwDQYJKoZIhvcNAQEFBQAwfTELMAkGA1UEBhMCSUwxFjAUBgNVBAoT DVN0YXJ0Q29tIEx0ZC4xKzApBgNVBAsTIlNlY3VyZSBEaWdpdGFsIENlcnRpZmljYXRlIFNp Z25pbmcxKTAnBgNVBAMTIFN0YXJ0Q29tIENlcnRpZmljYXRpb24gQXV0aG9yaXR5MB4XDTA3 MTAyNDIxMDI1NVoXDTE3MTAyNDIxMDI1NVowgYwxCzAJBgNVBAYTAklMMRYwFAYDVQQKEw1T dGFydENvbSBMdGQuMSswKQYDVQQLEyJTZWN1cmUgRGlnaXRhbCBDZXJ0aWZpY2F0ZSBTaWdu aW5nMTgwNgYDVQQDEy9TdGFydENvbSBDbGFzcyAyIFByaW1hcnkgSW50ZXJtZWRpYXRlIENs aWVudCBDQTCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAMsohUWcASz7GfKrpTOM KqANy9BV7V0igWdGxA8IU77L3aTxErQ+fcxtDYZ36Z6GH0YFn7fq5RADteP0AYzrCA+EQTfi 8q1+kA3m0nwtwXG94M5sIqsvs7lRP1aycBke/s5g9hJHryZ2acScnzczjBCAo7X1v5G3yw8M DP2m2RCye0KfgZ4nODerZJVzhAlOD9YejvAXZqHksw56HzElVIoYSZ3q4+RJuPXXfIoyby+Y 2m1E+YzX5iCZXBx05gk6MKAW1vaw4/v2OOLy6FZH3XHHtOkzUreG//CsFnB9+uaYSlR65cdG zTsmoIK8WH1ygoXhRBm98SD7Hf/r3FELNvUCAwEAAaOCAa0wggGpMA8GA1UdEwEB/wQFMAMB Af8wDgYDVR0PAQH/BAQDAgEGMB0GA1UdDgQWBBSuVYNv7DHKufcd+q9rMfPIHeOsuzAfBgNV HSMEGDAWgBROC+8apEBbpRdphzDKNGhD0EGu8jBmBggrBgEFBQcBAQRaMFgwJwYIKwYBBQUH MAGGG2h0dHA6Ly9vY3NwLnN0YXJ0c3NsLmNvbS9jYTAtBggrBgEFBQcwAoYhaHR0cDovL3d3 dy5zdGFydHNzbC5jb20vc2ZzY2EuY3J0MFsGA1UdHwRUMFIwJ6AloCOGIWh0dHA6Ly93d3cu c3RhcnRzc2wuY29tL3Nmc2NhLmNybDAnoCWgI4YhaHR0cDovL2NybC5zdGFydHNzbC5jb20v c2ZzY2EuY3JsMIGABgNVHSAEeTB3MHUGCysGAQQBgbU3AQIBMGYwLgYIKwYBBQUHAgEWImh0 dHA6Ly93d3cuc3RhcnRzc2wuY29tL3BvbGljeS5wZGYwNAYIKwYBBQUHAgEWKGh0dHA6Ly93 d3cuc3RhcnRzc2wuY29tL2ludGVybWVkaWF0ZS5wZGYwDQYJKoZIhvcNAQEFBQADggIBADqp Jw3I07QWke9plNBpxUxcffc7nUrIQpJHDci91DFG7fVhHRkMZ1J+BKg5UNUxIFJ2Z9B90Mic c/NXcs7kPBRdn6XGO/vPc87Y6R+cWS9Nc9+fp3Enmsm94OxOwI9wn8qnr/6o3mD4noP9Jphw UPTXwHovjavRnhUQHLfo/i2NG0XXgTHXS2Xm0kVUozXqpYpAdumMiB/vezj1QHQJDmUdPYMc p+reg9901zkyT3fDW/ivJVv6pWtkh6Pw2ytZT7mvg7YhX3V50Nv860cV11mocUVcqBLv0gcT +HBDYtbuvexNftwNQKD5193A7zN4vG7CTYkXxytSjKuXrpEatEiFPxWgb84nVj25SU5q/r1X hwby6mLhkbaXslkVtwEWT3Van49rKjlK4XrUKYYWtnfzq6aSak5u0Vpxd1rY79tWhD3EdCvO hNz/QplNa+VkIsrcp7+8ZhP1l1b2U6MaxIVteuVMD3X0vziIwr7jxYae9FZjbxlpUemqXjcC 0QaFfN7qI0JsQMALL7iGRBg7K0CoOBzECdD3fuZil5kU/LP9cr1BK31U0Uy651bFnAMMMkqh AChIbn0ei72VnbpSsrrSdF0BAGYQ8vyHae5aCg+H75dVCV33K6FuxZrf09yTz+Vx/PkdRUYk XmZz/OTfyJXsUOUXrym6KvI2rYpccSk5MIIHRDCCBiygAwIBAgICJYcwDQYJKoZIhvcNAQEF BQAwgYwxCzAJBgNVBAYTAklMMRYwFAYDVQQKEw1TdGFydENvbSBMdGQuMSswKQYDVQQLEyJT ZWN1cmUgRGlnaXRhbCBDZXJ0aWZpY2F0ZSBTaWduaW5nMTgwNgYDVQQDEy9TdGFydENvbSBD bGFzcyAyIFByaW1hcnkgSW50ZXJtZWRpYXRlIENsaWVudCBDQTAeFw0xMjA4MjkyMzM0MjZa Fw0xNDA4MzExMzE0MzFaMIGOMRkwFwYDVQQNExBpd3JteTFzNGhOaHZLMDQ0MQswCQYDVQQG EwJDQTEZMBcGA1UECBMQQnJpdGlzaCBDb2x1bWJpYTESMBAGA1UEBxMJVmFuY291dmVyMRUw EwYDVQQDEwxQZXRlciBLaWVzZXIxHjAcBgkqhkiG9w0BCQEWD3BldGVyQGtpZXNlci5jYTCC ASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEBAOdZjqh64jWRFwTsYZZ0bKt5xOIxLlV4 jrN0wY5KMu5RotLfYnu53fCMGJVk1n8h4QFRDxGuQmE4ugw47rv7FMDWYPb7PisPAWbcbUlG pmxhZB/avqpC8P2uuvJ0dsKsyNo8HeROfvrLkT6PSpYE35UXTLESoHSYkkyhcklVRf6ygChd PKUMNhEAMH3ZGtsw8N24hSoiW6Sb3vqv4ZCZcLvlKRVjJtOyc2vbSw8ndc62EbFMFeP+AZOw r7flFGQanYjfeXeeXV/29hstVPv88okwEpJCWdmSA1/gh5Yc6bjpQ7YuSxOVKP5UAl+Ehyld XWIcWEcUoeuZ1XeSyRuwRmcCAwEAAaOCA6owggOmMAkGA1UdEwQCMAAwCwYDVR0PBAQDAgSw MB0GA1UdJQQWMBQGCCsGAQUFBwMCBggrBgEFBQcDBDAdBgNVHQ4EFgQUKlB/4e9ZfesCCiNm UHJOZibv8FAwHwYDVR0jBBgwFoAUrlWDb+wxyrn3HfqvazHzyB3jrLswGgYDVR0RBBMwEYEP cGV0ZXJAa2llc2VyLmNhMIICIQYDVR0gBIICGDCCAhQwggIQBgsrBgEEAYG1NwECAjCCAf8w LgYIKwYBBQUHAgEWImh0dHA6Ly93d3cuc3RhcnRzc2wuY29tL3BvbGljeS5wZGYwNAYIKwYB BQUHAgEWKGh0dHA6Ly93d3cuc3RhcnRzc2wuY29tL2ludGVybWVkaWF0ZS5wZGYwgfcGCCsG AQUFBwICMIHqMCcWIFN0YXJ0Q29tIENlcnRpZmljYXRpb24gQXV0aG9yaXR5MAMCAQEagb5U aGlzIGNlcnRpZmljYXRlIHdhcyBpc3N1ZWQgYWNjb3JkaW5nIHRvIHRoZSBDbGFzcyAyIFZh bGlkYXRpb24gcmVxdWlyZW1lbnRzIG9mIHRoZSBTdGFydENvbSBDQSBwb2xpY3ksIHJlbGlh bmNlIG9ubHkgZm9yIHRoZSBpbnRlbmRlZCBwdXJwb3NlIGluIGNvbXBsaWFuY2Ugb2YgdGhl IHJlbHlpbmcgcGFydHkgb2JsaWdhdGlvbnMuMIGcBggrBgEFBQcCAjCBjzAnFiBTdGFydENv bSBDZXJ0aWZpY2F0aW9uIEF1dGhvcml0eTADAgECGmRMaWFiaWxpdHkgYW5kIHdhcnJhbnRp ZXMgYXJlIGxpbWl0ZWQhIFNlZSBzZWN0aW9uICJMZWdhbCBhbmQgTGltaXRhdGlvbnMiIG9m IHRoZSBTdGFydENvbSBDQSBwb2xpY3kuMDYGA1UdHwQvMC0wK6ApoCeGJWh0dHA6Ly9jcmwu c3RhcnRzc2wuY29tL2NydHUyLWNybC5jcmwwgY4GCCsGAQUFBwEBBIGBMH8wOQYIKwYBBQUH MAGGLWh0dHA6Ly9vY3NwLnN0YXJ0c3NsLmNvbS9zdWIvY2xhc3MyL2NsaWVudC9jYTBCBggr BgEFBQcwAoY2aHR0cDovL2FpYS5zdGFydHNzbC5jb20vY2VydHMvc3ViLmNsYXNzMi5jbGll bnQuY2EuY3J0MCMGA1UdEgQcMBqGGGh0dHA6Ly93d3cuc3RhcnRzc2wuY29tLzANBgkqhkiG 9w0BAQUFAAOCAQEAvd8Wn0ZXlB3mV+fWae/hAFquDNjyWMJ29rJymKaGOOYTCiPdmDRJNV9R k0YTP9+B06A0Vx6bbg+rZwIdv2k+GBSjCSb4T8IsawVphbbWMohFzxGzo36NaYZ/wCTcrlVv oXmPFkEaOJzqQ1DAYetJTfDMIfkBeOZSJ9KmdLos1Z9fOc0nGq9ioy/6gIPGchsWuhrl3vxW ej1MUPjVKn5wW967cPcLFnNLR1gxYB3fjptyHbJpRq/54rH2BMR0kicK9EyVUoDM35R6Ux6n djaJmH1ZFcHVc+FmalNisvlIlGSWwnkyvpmyD25LSJ+BlfZEUHE8tcicdZPAqQ8f+Yo/dTGC A9owggPWAgEBMIGTMIGMMQswCQYDVQQGEwJJTDEWMBQGA1UEChMNU3RhcnRDb20gTHRkLjEr MCkGA1UECxMiU2VjdXJlIERpZ2l0YWwgQ2VydGlmaWNhdGUgU2lnbmluZzE4MDYGA1UEAxMv U3RhcnRDb20gQ2xhc3MgMiBQcmltYXJ5IEludGVybWVkaWF0ZSBDbGllbnQgQ0ECAiWHMAkG BSsOAwIaBQCgggIbMBgGCSqGSIb3DQEJAzELBgkqhkiG9w0BBwEwHAYJKoZIhvcNAQkFMQ8X DTE0MDUyNzIwMTMzMFowIwYJKoZIhvcNAQkEMRYEFC+B5lAgqqunJb7ft8M4L0iPWFerMGwG CSqGSIb3DQEJDzFfMF0wCwYJYIZIAWUDBAEqMAsGCWCGSAFlAwQBAjAKBggqhkiG9w0DBzAO BggqhkiG9w0DAgICAIAwDQYIKoZIhvcNAwICAUAwBwYFKw4DAgcwDQYIKoZIhvcNAwICASgw gaQGCSsGAQQBgjcQBDGBljCBkzCBjDELMAkGA1UEBhMCSUwxFjAUBgNVBAoTDVN0YXJ0Q29t IEx0ZC4xKzApBgNVBAsTIlNlY3VyZSBEaWdpdGFsIENlcnRpZmljYXRlIFNpZ25pbmcxODA2 BgNVBAMTL1N0YXJ0Q29tIENsYXNzIDIgUHJpbWFyeSBJbnRlcm1lZGlhdGUgQ2xpZW50IENB AgIlhzCBpgYLKoZIhvcNAQkQAgsxgZaggZMwgYwxCzAJBgNVBAYTAklMMRYwFAYDVQQKEw1T dGFydENvbSBMdGQuMSswKQYDVQQLEyJTZWN1cmUgRGlnaXRhbCBDZXJ0aWZpY2F0ZSBTaWdu aW5nMTgwNgYDVQQDEy9TdGFydENvbSBDbGFzcyAyIFByaW1hcnkgSW50ZXJtZWRpYXRlIENs aWVudCBDQQICJYcwDQYJKoZIhvcNAQEBBQAEggEAW5milJ5BkvnIifDi19yqprHSQoWpW95B CiKFsL0NpZqoZsJAGqT8Mwvb62RUwCXWrsHSfLIH1FY1MQpm0wizq1+Y12JoOmiYsps1J9S+ LTcgnWlBrjNz/LLNVz6V5ZAHkBXDngY6AJ+R5y7mEZphVwOI/8eI1VKhPKsGENsVPjiuBFC2 X+nJ6MGA8NYawRNAiZ99Y4Y35LIgSaJmBqFJTW3iPfyyxJ7k1N8VKTAEW0NQjWWy8TW0u7Np 1v6d0KkA6ItT83HUFpLvSY4FYuQQRdH5vMB8WgCTmn9CXydN8U/Hc/08KAxItFUW+U4uqykj DB/NuqFpfDjqtBHozwzCagAAAAAAAA== --------------ms050907040901030807070402--