Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Wed, 21 Aug 2002 10:13:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Wed, 21 Aug 2002 10:13:09 -0400 Received: from zeus.kernel.org ([204.152.189.113]:7094 "EHLO zeus.kernel.org") by vger.kernel.org with ESMTP id ; Wed, 21 Aug 2002 10:13:04 -0400 Message-ID: <3D63A2FC.92BA1342@otpbank.hu> Date: Wed, 21 Aug 2002 16:26:04 +0200 From: Nagy Tibor X-Mailer: Mozilla 4.79 [en] (X11; U; Linux 2.4.18 i686) X-Accept-Language: hu, en MIME-Version: 1.0 To: linux-kernel@vger.kernel.org Subject: Dell Perc 3/QC performance Content-Type: multipart/signed; protocol="application/x-pkcs7-signature"; micalg=sha1; boundary="------------msD99E45FE60C268541AF7ECFE" Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 6896 Lines: 163 This is a cryptographically signed message in MIME format. --------------msD99E45FE60C268541AF7ECFE Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Hi, I am not satisfied with the disk I/O performance of the RAID controller 'Dell Perc 3/QC' (AMI megaraid) under Linux. Short description of my problem: We have a Dell PowerEdge 6600 + PERC 3/QC, and I am not satisfied with the performance. I/O speed is not linearly growing if I read more disks simultenausly. If I read 1 disk, I get about 49 MB/s read speed, if I read 2 disks simultaneosly I get about 64 MB/s read speed (only +15MB/s), if I read 3 disks simultaneosly I get about 68 MB/s read speed (only +4MB/s), If I read more disk I don't get higher speed. Do you have any idea, what is the problem? Detailed description: 1. Configuration Dell Poweredge 6600: 4 x 1400 MHz, 4 GB RAM PERC 3/QC Firmware: 1.61N Bios: 3.17 Logical drive 0 (18 GB) - RAID 1 - Channel 0 Id 0 - 18 GB \ Channel 0 Id 1 - 18 GB Logical drive 1 (22 GB) - RAID 1 - Channel 2 Id 0 - 72 GB Logical drive 2 (22 GB) + \ Channel 3 Id 9 - 72 GB Logical drive 3 (24 GB) / Logical drive 4 (22 GB) - RAID 1 - Channel 2 Id 1 - 72 GB Logical drive 5 (22 GB) + \ Channel 3 Id 10 - 72 GB Logical drive 6 (24 GB) / Logical drive 7 (22 GB) - RAID 1 - Channel 2 Id 2 - 72 GB Logical drive 8 (22 GB) + \ Channel 3 Id 11 - 72 GB Logical drive 9 (24 GB) / 18 GB disks: Quantum ATLAS 10KIII 18 SCA (160 MB SCSI) 72 GB disks: Hitachi DK32DJ-72 (160 MB SCSI) The 18 GB disks are installed in the server itself, the 72 GB disks are installed in a PowerVault 221S disk tower with splitted backplane. The 72 GB disks are splitted into 22-24 GB logical drives, because Informix database engine can use max 2GB chunks (partitions), and only 15 partitions can be installed in linux on 1 drive. 'Cache policy' is set to 'Direct IO' and 'Read (ahead) policy' to 'adaptive' for all logical drives. (I tried other confugurations, too.) Logical drives 1-9 are used as raw devices by informix, logical drive 0 is for the operating system. 2. Operating system SuSe Linux 8.0, kernel 2.4.18 emiir:~ # uname -a Linux emiir 2.4.18-64GB-SMP #1 SMP Wed Mar 27 13:58:12 UTC 2002 i686 unknown 3. I/O test 3.1 Read from Logical drive 1 dd if=/dev/rsdb1 of=/dev/null bs=1024k -> 49 MB/s I/O 3.2 Read from Logical drive 1 and 4 (different disks) dd if=/dev/rsdb1 of=/dev/null bs=1024k & dd if=/dev/rsde1 of=/dev/null bs=1024k & -> 64 MB/s I/O 3.2 Read from Logical drive 1, 4 and 7 (different disks) dd if=/dev/rsdb1 of=/dev/null bs=1024k & dd if=/dev/rsde1 of=/dev/null bs=1024k & dd if=/dev/rsdh1 of=/dev/null bs=1024k & -> 68 MB/s I/O All I/O speed came from the column 'bi' of 'vmstat 1'. 4. Result I do not understand, why the speed is not increased nearly linearly. The I/O between the PERC controller and the host is 64 bit PCI with 66MHz, ca. 530MB/s, each of the four SCSI channel has a speed of 160MB/s. At least test 3.2 should result the double of the speed of test 3.1 (two SCSI channel, separate disks). I see also on the dell site 300 MB/s for sequential read: http://www.dell.com/us/en/biz/topics/power_ps1q02-perc.htm Do you have any idea what can be wrong? Than you Tibor ------------------------------------------------------------------------ Tibor Nagy National Savings and Commercial Bank Ltd (OTP Bank) H-1051 Budapest Nador u. 16. Tel: 00 36 1 374 6990 Fax: 00 36 1 374 6981 E-mail: nagyt@otpbank.hu ------------------------------------------------------------------------ --------------msD99E45FE60C268541AF7ECFE Content-Type: application/x-pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIIH5wYJKoZIhvcNAQcCoIIH2DCCB9QCAQExCzAJBgUrDgMCGgUAMAsGCSqGSIb3DQEHAaCC BbowggJ6MIIB46ADAgECAgMHn6wwDQYJKoZIhvcNAQEEBQAwgZIxCzAJBgNVBAYTAlpBMRUw EwYDVQQIEwxXZXN0ZXJuIENhcGUxEjAQBgNVBAcTCUNhcGUgVG93bjEPMA0GA1UEChMGVGhh d3RlMR0wGwYDVQQLExRDZXJ0aWZpY2F0ZSBTZXJ2aWNlczEoMCYGA1UEAxMfUGVyc29uYWwg RnJlZW1haWwgUlNBIDIwMDAuOC4zMDAeFw0wMjA2MDUxMTE1MzJaFw0wMzA2MDUxMTE1MzJa MEIxHzAdBgNVBAMTFlRoYXd0ZSBGcmVlbWFpbCBNZW1iZXIxHzAdBgkqhkiG9w0BCQEWEG5h Z3l0QG90cGJhbmsuaHUwgZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBAMzA1PHsL3+xE06d 23p7BlCJJYSyi1vsfYeVmB4dsc/OSg/y4WxqOILMh+3wxQ35FNs23AjnYfRljhGNtoSm5jRe ioE19dUKG1FCV0T1RMYTE8tXRzt9YzOAr2koWg/+Wqxt/0Qi9fl1PtgrYliS5cC0kBRND9Yb aybBEoFNPrSZAgMBAAGjLTArMBsGA1UdEQQUMBKBEG5hZ3l0QG90cGJhbmsuaHUwDAYDVR0T AQH/BAIwADANBgkqhkiG9w0BAQQFAAOBgQBJUxrLMZI2MLY9RnIXFM77knDXEdzyneSa04p6 egw5r6YSzHKnm2seObq5EkDk5vD6n0ZRZaZzbhMu+1QHIJ2v3FUMNqb37ZrROjzJqtLrcOHB kVr5kNblco2VJUozzGJguLclckzTUsgXWAelq2EjN4TRoJVdwMp1Ld6YqOW3VzCCAzgwggKh oAMCAQICEGZFcrfMdPXPY3ZFhNAukQEwDQYJKoZIhvcNAQEEBQAwgdExCzAJBgNVBAYTAlpB MRUwEwYDVQQIEwxXZXN0ZXJuIENhcGUxEjAQBgNVBAcTCUNhcGUgVG93bjEaMBgGA1UEChMR VGhhd3RlIENvbnN1bHRpbmcxKDAmBgNVBAsTH0NlcnRpZmljYXRpb24gU2VydmljZXMgRGl2 aXNpb24xJDAiBgNVBAMTG1RoYXd0ZSBQZXJzb25hbCBGcmVlbWFpbCBDQTErMCkGCSqGSIb3 DQEJARYccGVyc29uYWwtZnJlZW1haWxAdGhhd3RlLmNvbTAeFw0wMDA4MzAwMDAwMDBaFw0w NDA4MjcyMzU5NTlaMIGSMQswCQYDVQQGEwJaQTEVMBMGA1UECBMMV2VzdGVybiBDYXBlMRIw EAYDVQQHEwlDYXBlIFRvd24xDzANBgNVBAoTBlRoYXd0ZTEdMBsGA1UECxMUQ2VydGlmaWNh dGUgU2VydmljZXMxKDAmBgNVBAMTH1BlcnNvbmFsIEZyZWVtYWlsIFJTQSAyMDAwLjguMzAw gZ8wDQYJKoZIhvcNAQEBBQADgY0AMIGJAoGBAN4zMqZjxwklRT7SbngnZ4HF2ogZgpcO40Qp imM1Km1wPPrcrvfudG8wvDOQf/k0caCjbZjxw0+iZdsN+kvx1t1hpfmFzVWaNRqdknWoJ67Y cvm6AvbXsJHeHOmr4BgDqHxDQlBRh4M88Dm0m1SKE4f/s5udSWYALQmJ7JRr6aFpAgMBAAGj TjBMMCkGA1UdEQQiMCCkHjAcMRowGAYDVQQDExFQcml2YXRlTGFiZWwxLTI5NzASBgNVHRMB Af8ECDAGAQH/AgEAMAsGA1UdDwQEAwIBBjANBgkqhkiG9w0BAQQFAAOBgQAxsUtHXfkBceX1 U2xdedY9mMAmE2KBIqcS+CKV6BtJtyd7BDm6/ObyJOuR+r3sDSo491BVqGz3Da1MG7wD9LXr okefbKIMWI0xQgkRbLAaadErErJAXWr5edDqLiXdiuT82w0fnQLzWtvKPPZE6iZph39Ins6l n+eE2MliYq0FxjGCAfUwggHxAgEBMIGaMIGSMQswCQYDVQQGEwJaQTEVMBMGA1UECBMMV2Vz dGVybiBDYXBlMRIwEAYDVQQHEwlDYXBlIFRvd24xDzANBgNVBAoTBlRoYXd0ZTEdMBsGA1UE CxMUQ2VydGlmaWNhdGUgU2VydmljZXMxKDAmBgNVBAMTH1BlcnNvbmFsIEZyZWVtYWlsIFJT QSAyMDAwLjguMzACAwefrDAJBgUrDgMCGgUAoIGxMBgGCSqGSIb3DQEJAzELBgkqhkiG9w0B BwEwHAYJKoZIhvcNAQkFMQ8XDTAyMDgyMTE0MjYwNlowIwYJKoZIhvcNAQkEMRYEFMiFaaD+ i85N9S4O4E6gEUt44nXJMFIGCSqGSIb3DQEJDzFFMEMwCgYIKoZIhvcNAwcwDgYIKoZIhvcN AwICAgCAMAcGBSsOAwIHMA0GCCqGSIb3DQMCAgFAMA0GCCqGSIb3DQMCAgEoMA0GCSqGSIb3 DQEBAQUABIGAjYsTPXgCoyaL49oERaLvRyhNDDTriEcZ6BIDUNX28SaMCsUbkH1j32NRGQjO +LkeYAZcx03Cnvu5e0PZQENLIt3ChRXoTTjyjQLFKfM95u4DX6VFfxsd7DKVn8udgLidaPmn 6Y5faJ+Q/wy8RVA3uginvU8BI072soMbbU9KlTg= --------------msD99E45FE60C268541AF7ECFE-- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/