From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f180.google.com ([209.85.213.180]:48743 "EHLO mail-ig0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754377AbaJWLjg (ORCPT ); Thu, 23 Oct 2014 07:39:36 -0400 Received: by mail-ig0-f180.google.com with SMTP id uq10so1166634igb.13 for ; Thu, 23 Oct 2014 04:39:35 -0700 (PDT) Message-ID: <5448E8F0.7070004@gmail.com> Date: Thu, 23 Oct 2014 07:39:28 -0400 From: Austin S Hemmelgarn MIME-Version: 1.0 To: miaox@cn.fujitsu.com, =?UTF-8?B?UGlvdHIgUGF3xYJvdw==?= , Chris Murphy , linux-btrfs Subject: Re: device balance times References: <845c0ca8cc78ed97da487bf7f4b7b122@admin.virtall.com> <5446BEC0.8070009@siedziba.pl> <02A17DFE-290C-4447-99E9-D39480D7A26A@colorremedies.com> <5447A5CF.9060405@siedziba.pl> <5448C81E.4060701@cn.fujitsu.com> In-Reply-To: <5448C81E.4060701@cn.fujitsu.com> Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha1; boundary="------------ms050000070806060908070906" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms050000070806060908070906 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable On 2014-10-23 05:19, Miao Xie wrote: > On Wed, 22 Oct 2014 14:40:47 +0200, Piotr Paw=C5=82ow wrote: >> On 22.10.2014 03:43, Chris Murphy wrote: >>> On Oct 21, 2014, at 4:14 PM, Piotr Paw=C5=82ow wrote= : >>>> Looks normal to me. Last time I started a balance after adding 6th d= evice to my FS, it took 4 days to move 25GBs of data. >>> It's long term untenable. At some point it must be fixed. It's way, w= ay slower than md raid. >>> At a certain point it needs to fallback to block level copying, with = a ~ 32KB block. It can't be treating things as if they're 1K files, doing= file level copying that takes forever. It's just too risky that another = device fails in the meantime. >> >> There's "device replace" for restoring redundancy, which is fast, but = not implemented yet for RAID5/6. > > Now my colleague and I is implementing the scrub/replace for RAID5/6 > and I have a plan to reimplement the balance and split it off from the = metadata/file data process. the main idea is > - allocate a new chunk which has the same size as the relocated one, bu= t don't insert it into the block group list, so we don't > allocate the free space from it. > - set the source chunk to be Read-only > - copy the data from the source chunk to the new chunk > - replace the extent map of the source chunk with the one of the new ch= unk(The new chunk has > the same logical address and the length as the old one) > - release the source chunk > > By this way, we needn't deal the data one extent by one extent, and nee= dn't do any space reservation, > so the speed will be very fast even we have lots of snapshots. > Even if balance gets re-implemented this way, we should still provide=20 some way to consolidate the data from multiple partially full chunks.=20 Maybe keep the old balance path and have some option (maybe call it=20 aggressive?) that turns it on instead of the new code. --------------ms050000070806060908070906 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExCzAJBgUrDgMCGgUAMIAGCSqGSIb3DQEHAQAAoIIFuDCC BbQwggOcoAMCAQICAw9gVDANBgkqhkiG9w0BAQ0FADB5MRAwDgYDVQQKEwdSb290IENBMR4w HAYDVQQLExVodHRwOi8vd3d3LmNhY2VydC5vcmcxIjAgBgNVBAMTGUNBIENlcnQgU2lnbmlu ZyBBdXRob3JpdHkxITAfBgkqhkiG9w0BCQEWEnN1cHBvcnRAY2FjZXJ0Lm9yZzAeFw0xNDA4 MDgxMTMwNDRaFw0xNTAyMDQxMTMwNDRaMGMxGDAWBgNVBAMTD0NBY2VydCBXb1QgVXNlcjEj MCEGCSqGSIb3DQEJARYUYWhmZXJyb2luN0BnbWFpbC5jb20xIjAgBgkqhkiG9w0BCQEWE2Fo ZW1tZWxnQG9oaW9ndC5jb20wggEiMA0GCSqGSIb3DQEBAQUAA4IBDwAwggEKAoIBAQDdmm8R BM5D6fGiB6rpogPZbLYu6CkU6834rcJepfmxKnLarYUYM593/VGygfaaHAyuc8qLaRA3u1M0 Qp29flqmhv1VDTBZ+zFu6JgHjTDniBii1KOZRo0qV3jC5NvaS8KUM67+eQBjm29LhBWVi3+e a8jLxmogFXV0NGej+GHIr5zA9qKz2WJOEoGh0EfqZ2MQTmozcGI43/oqIYhRj8fRMkWXLUAF WsLzPQMpK19hD8fqwlxQWhBV8gsGRG54K5pyaQsjne7m89SF5M8JkNJPH39tHEvfv2Vhf7EM Y4WGyhLAULSlym1AI1uUHR1FfJaj3AChaEJZli/AdajYsqc7AgMBAAGjggFZMIIBVTAMBgNV HRMBAf8EAjAAMFYGCWCGSAGG+EIBDQRJFkdUbyBnZXQgeW91ciBvd24gY2VydGlmaWNhdGUg Zm9yIEZSRUUgaGVhZCBvdmVyIHRvIGh0dHA6Ly93d3cuQ0FjZXJ0Lm9yZzAOBgNVHQ8BAf8E BAMCA6gwQAYDVR0lBDkwNwYIKwYBBQUHAwQGCCsGAQUFBwMCBgorBgEEAYI3CgMEBgorBgEE AYI3CgMDBglghkgBhvhCBAEwMgYIKwYBBQUHAQEEJjAkMCIGCCsGAQUFBzABhhZodHRwOi8v b2NzcC5jYWNlcnQub3JnMDEGA1UdHwQqMCgwJqAkoCKGIGh0dHA6Ly9jcmwuY2FjZXJ0Lm9y Zy9yZXZva2UuY3JsMDQGA1UdEQQtMCuBFGFoZmVycm9pbjdAZ21haWwuY29tgRNhaGVtbWVs Z0BvaGlvZ3QuY29tMA0GCSqGSIb3DQEBDQUAA4ICAQCr4klxcZU/PDRBpUtlb+d6JXl2dfto OUP/6g19dpx6Ekt2pV1eujpIj5whh5KlCSPUgtHZI7BcksLSczQbxNDvRu6LNKqGJGvcp99k cWL1Z6BsgtvxWKkOmy1vB+2aPfDiQQiMCCLAqXwHiNDZhSkwmGsJ7KHMWgF/dRVDnsl6aOQZ jAcBMpUZxzA/bv4nY2PylVdqJWp9N7x86TF9sda1zRZiyUwy83eFTDNzefYPtc4MLppcaD4g Wt8U6T2ffQfCWVzDirhg4WmDH3MybDItjkSB2/+pgGOS4lgtEBMHzAGQqQ+5PojTHRyqu9Jc O59oIGrTaOtKV9nDeDtzNaQZgygJItJi9GoAl68AmIHxpS1rZUNV6X8ydFrEweFdRTVWhUEL 70Cnx84YBojXv01LYBSZaq18K8cERPLaIrUD2go+2ffjdE9ejvYDhNBllY+ufvRizIjQA1uC OdktVAN6auQob94kOOsWpoMSrzHHvOvVW/kbokmKzaLtcs9+nJoL+vPi2AyzbaoQASVZYOGW pE3daA0F5FJfcPZKCwd5wdnmT3dU1IRUxa5vMmgjP20lkfP8tCPtvZv2mmI2Nw5SaXNY4gVu WQrvkV2in+TnGqgEIwUrLVbx9G6PSYZZs07czhO+Q1iVuKdAwjL/AYK0Us9v50acIzbl5CWw ZGj3wjGCA6EwggOdAgEBMIGAMHkxEDAOBgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6 Ly93d3cuY2FjZXJ0Lm9yZzEiMCAGA1UEAxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEh MB8GCSqGSIb3DQEJARYSc3VwcG9ydEBjYWNlcnQub3JnAgMPYFQwCQYFKw4DAhoFAKCCAfUw GAYJKoZIhvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTQxMDIzMTEzOTI4 WjAjBgkqhkiG9w0BCQQxFgQU0nYXx42D8jvxjL7vNBEC3t0CF6gwbAYJKoZIhvcNAQkPMV8w XTALBglghkgBZQMEASowCwYJYIZIAWUDBAECMAoGCCqGSIb3DQMHMA4GCCqGSIb3DQMCAgIA gDANBggqhkiG9w0DAgIBQDAHBgUrDgMCBzANBggqhkiG9w0DAgIBKDCBkQYJKwYBBAGCNxAE MYGDMIGAMHkxEDAOBgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6Ly93d3cuY2FjZXJ0 Lm9yZzEiMCAGA1UEAxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEhMB8GCSqGSIb3DQEJ ARYSc3VwcG9ydEBjYWNlcnQub3JnAgMPYFQwgZMGCyqGSIb3DQEJEAILMYGDoIGAMHkxEDAO BgNVBAoTB1Jvb3QgQ0ExHjAcBgNVBAsTFWh0dHA6Ly93d3cuY2FjZXJ0Lm9yZzEiMCAGA1UE AxMZQ0EgQ2VydCBTaWduaW5nIEF1dGhvcml0eTEhMB8GCSqGSIb3DQEJARYSc3VwcG9ydEBj YWNlcnQub3JnAgMPYFQwDQYJKoZIhvcNAQEBBQAEggEAH2r7XbOMiFLlzvckekZlpWBpg/Bo 8jzfftRgR9nLusFjw91cWCWxhrwp+Jm5TQagYm66y+JOYPcPoYgVbXPi8iCsHx7nkrbqcf1j zmbItbnJtBigqRPDoH64c1SfzmoGWb37viv43Y/ih0bGPEa3vhuNjXV/qXi2KeqEQO9BRa2I E4CXAzKxYHn5R1QRAunzXhJS3fQ2oV++3inNt+27/XW2BZCSvQm0FBPZVNjLiokfD7gaf0mE o1ni1uDn41TQTra4i1UpZcDDfPkKDY99SeG+xqnP7mCWxscR/cPAe0fdp+BPb2eH/xwic49h 6Z/aXkCZ0kwsFyGK2BNdS1GoFgAAAAAAAA== --------------ms050000070806060908070906--