From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f175.google.com ([209.85.213.175]:35009 "EHLO mail-ig0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933211AbbHDL27 (ORCPT ); Tue, 4 Aug 2015 07:28:59 -0400 Received: by igr7 with SMTP id 7so72366494igr.0 for ; Tue, 04 Aug 2015 04:28:59 -0700 (PDT) Subject: Re: mount btrfs takes 30 minutes, btrfs check runs out of memory To: John Ettedgui , Qu Wenruo References: <55BADEC4.3020409@cn.fujitsu.com> <55BAFEF9.1070107@cn.fujitsu.com> <55BB0A39.1050208@cn.fujitsu.com> <55C017E7.40704@cn.fujitsu.com> <55C02AF9.3070600@cn.fujitsu.com> Cc: btrfs From: Austin S Hemmelgarn Message-ID: <55C0A1ED.6020407@gmail.com> Date: Tue, 4 Aug 2015 07:28:45 -0400 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; protocol="application/pkcs7-signature"; micalg=sha-512; boundary="------------ms070807030402010801000803" Sender: linux-btrfs-owner@vger.kernel.org List-ID: This is a cryptographically signed message in MIME format. --------------ms070807030402010801000803 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: quoted-printable On 2015-08-04 00:58, John Ettedgui wrote: > On Mon, Aug 3, 2015 at 8:01 PM, Qu Wenruo wro= te: >> Although the best practice is staying away from such converted fs, eit= her >> using pure, newly created btrfs, or convert back to ext* before any ba= lance. >> > Unfortunately I don't have enough hard drive space to do a clean > btrfs, so my only way to use btrfs for that partition was a > conversion. If you could get your hands on a decent sized flash drive (32G or more), = you could do an incremental conversion offline. The steps would look=20 something like this: 1. Boot the system into a LiveCD or something similar that doesn't need=20 to run from your regular root partition (SystemRescueCD would be my=20 personal recommendation, although if you go that way, make sure to boot=20 the alternative kernel, as it's a lot newer then the standard ones). 2. Plug in the flash drive, format it as BTRFS. 3. Mount both your old partition and the flash drive somewhere. 4. Start copying files from the old partition to the flash drive. 5. When you hit ENOSPC on the flash drive, unmount the old partition,=20 shrink it down to the minimum size possible, and create a new partition=20 in the free space produced by doing so. 6. Add the new partition to the BTRFS filesystem on the flash drive. 7. Repeat steps 4-6 until you have copied everything. 8. Wipe the old partition, and add it to the BTRFS filesystem. 9. Run a full balance on the new BTRFS filesystem. 10. Delete the partition from step 5 that is closest to the old=20 partition (via btrfs device delete), then resize the old partition to=20 fill the space that the deleted partition took up. 11. Repeat steps 9-10 until the only remaining partitions in the new=20 BTRFS filesystem are the old one and the flash drive. 12. Delete the flash drive from the BTRFS filesystem. This takes some time and coordination, but it does work reliably as long = as you are careful (I've done it before on multiple systems). --------------ms070807030402010801000803 Content-Type: application/pkcs7-signature; name="smime.p7s" Content-Transfer-Encoding: base64 Content-Disposition: attachment; filename="smime.p7s" Content-Description: S/MIME Cryptographic Signature MIAGCSqGSIb3DQEHAqCAMIACAQExDzANBglghkgBZQMEAgMFADCABgkqhkiG9w0BBwEAAKCC Brgwgga0MIIEnKADAgECAgMQblUwDQYJKoZIhvcNAQENBQAweTEQMA4GA1UEChMHUm9vdCBD QTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNp Z25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcwHhcN MTUwMzI1MTkzNDM4WhcNMTUwOTIxMTkzNDM4WjBjMRgwFgYDVQQDEw9DQWNlcnQgV29UIFVz ZXIxIzAhBgkqhkiG9w0BCQEWFGFoZmVycm9pbjdAZ21haWwuY29tMSIwIAYJKoZIhvcNAQkB FhNhaGVtbWVsZ0BvaGlvZ3QuY29tMIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEA nQ/81tq0QBQi5w316VsVNfjg6kVVIMx760TuwA1MUaNQgQ3NyUl+UyFtjhpkNwwChjgAqfGd LIMTHAdObcwGfzO5uI2o1a8MHVQna8FRsU3QGouysIOGQlX8jFYXMKPEdnlt0GoQcd+BtESr pivbGWUEkPs1CwM6WOrs+09bAJP3qzKIr0VxervFrzrC5Dg9Rf18r9WXHElBuWHg4GYHNJ2V Ab8iKc10h44FnqxZK8RDN8ts/xX93i9bIBmHnFfyNRfiOUtNVeynJbf6kVtdHP+CRBkXCNRZ qyQT7gbTGD24P92PS2UTmDfplSBcWcTn65o3xWfesbf02jF6PL3BCrVnDRI4RgYxG3zFBJuG qvMoEODLhHKSXPAyQhwZINigZNdw5G1NqjXqUw+lIqdQvoPijK9J3eijiakh9u2bjWOMaleI SMRR6XsdM2O5qun1dqOrCgRkM0XSNtBQ2JjY7CycIx+qifJWsRaYWZz0aQU4ZrtAI7gVhO9h pyNaAGjvm7PdjEBiXq57e4QcgpwzvNlv8pG1c/hnt0msfDWNJtl3b6elhQ2Pz4w/QnWifZ8E BrFEmjeeJa2dqjE3giPVWrsH+lOvQQONsYJOuVb8b0zao4vrWeGmW2q2e3pdv0Axzm/60cJQ haZUv8+JdX9ZzqxOm5w5eUQSclt84u+D+hsCAwEAAaOCAVkwggFVMAwGA1UdEwEB/wQCMAAw VgYJYIZIAYb4QgENBEkWR1RvIGdldCB5b3VyIG93biBjZXJ0aWZpY2F0ZSBmb3IgRlJFRSBo ZWFkIG92ZXIgdG8gaHR0cDovL3d3dy5DQWNlcnQub3JnMA4GA1UdDwEB/wQEAwIDqDBABgNV HSUEOTA3BggrBgEFBQcDBAYIKwYBBQUHAwIGCisGAQQBgjcKAwQGCisGAQQBgjcKAwMGCWCG SAGG+EIEATAyBggrBgEFBQcBAQQmMCQwIgYIKwYBBQUHMAGGFmh0dHA6Ly9vY3NwLmNhY2Vy dC5vcmcwMQYDVR0fBCowKDAmoCSgIoYgaHR0cDovL2NybC5jYWNlcnQub3JnL3Jldm9rZS5j cmwwNAYDVR0RBC0wK4EUYWhmZXJyb2luN0BnbWFpbC5jb22BE2FoZW1tZWxnQG9oaW9ndC5j b20wDQYJKoZIhvcNAQENBQADggIBABr5e8W+NiTER+Q/7wiA2LxWN3UdhT3eZJjqqSlP370P KL5iWqeTfxQ67Ai/mHbJcT2PgAJ+/D2Ji+aRR03UWnU/vtOwzyDLUMstqnfl0Zs+sz/CJe7x nBA5jlpjC2DKuMVfbPze7eySaen7XSGFHKE1QoVIIpQ2kVjC4nbbJQnUbAVX1Iz29WxeVGt9 XYigz3tDPf3tglN+q23E7YjQl4abTIoM7i98yV1H9gfY8lFfKZ6jREB9+n6ie2EwS3Kat2mG tl2wBx4MfRnoSQSKsLKQ5oTwhWf0JqlFwpLfl374p0Njcykej9/jnWG8Ks1V/AXTHqI4eyIP Mf5yMZkPv7n7LS9WWKdG4Nd38iv4T2EiAaWsmgu+r81qL5CJu9AyA0SBS4ttKf6k3e63w2Mv N9R45vpQ3QhAhfWyFxFhZN95APe3YECDG3+XIRJpRYPEtHuIsOyzI70ajF93gg/BidvqKsmV MM2ccktDMfqwZXea6zey7F8Geu9R7BqjXmG2HlNuXu7e/xnHOgXf5D3wPmnRLlBhXL1Ch97a w2KjaupjpAHfFjv5kGnZXN87UvvlwzIZiKXwa3vTDwK+rrKn/sHPkfDZPSiyt/ZBIK6lX83P 34H/CzGg+Kx57rHYOIHGumIvpDa5vfWp8O0sGgawb1C2Aae4sTUVIWmIjVuGI062MYIE0TCC BM0CAQEwgYAweTEQMA4GA1UEChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNl cnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcN AQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxBuVTANBglghkgBZQMEAgMFAKCCAiEwGAYJKoZI hvcNAQkDMQsGCSqGSIb3DQEHATAcBgkqhkiG9w0BCQUxDxcNMTUwODA0MTEyODQ1WjBPBgkq hkiG9w0BCQQxQgRAMFfHDdeiKi1i4k0Q7mn0iISQhKlliLYTcrGB7P4c8NjtpblZ7NKu5rbA 2t9JPEcSHZ4F3PKiQW2uPKY2GwbhPzBsBgkqhkiG9w0BCQ8xXzBdMAsGCWCGSAFlAwQBKjAL BglghkgBZQMEAQIwCgYIKoZIhvcNAwcwDgYIKoZIhvcNAwICAgCAMA0GCCqGSIb3DQMCAgFA MAcGBSsOAwIHMA0GCCqGSIb3DQMCAgEoMIGRBgkrBgEEAYI3EAQxgYMwgYAweTEQMA4GA1UE ChMHUm9vdCBDQTEeMBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlD QSBDZXJ0IFNpZ25pbmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2Vy dC5vcmcCAxBuVTCBkwYLKoZIhvcNAQkQAgsxgYOggYAweTEQMA4GA1UEChMHUm9vdCBDQTEe MBwGA1UECxMVaHR0cDovL3d3dy5jYWNlcnQub3JnMSIwIAYDVQQDExlDQSBDZXJ0IFNpZ25p bmcgQXV0aG9yaXR5MSEwHwYJKoZIhvcNAQkBFhJzdXBwb3J0QGNhY2VydC5vcmcCAxBuVTAN BgkqhkiG9w0BAQEFAASCAgAZNF5Bo/BPp+0ALdhwHFbxIt0RlXxNW5SoyiGrcFhBLkdUgCv3 kXSeLOFpLd5IV+YQbtwaBd8anTgzjw1Ieqxm80FU7M4w0iSLBDzakir6rnE2xtHAkKL3UlMk FRUO28LCLBPp5fZ7YrMMMFyWIgbPlFIeFzJtyc5dSveO3RyuId7v/OtQwMyQ/QAqwYTnGXgd +V3b8VkdXV0wmleZ1tplGgZb0n3Niti1Z4gIUw6lFKHRFLZ85rCNWmO2BWEllBxE5FEssULl n5s6tlWGqVvucsxqfmPgdJ3CD1+zJ3rwuu88iC0HTx/quIage5lp087Bw8KNOKPIcDmqG4oG gGkRj/fxisZUnLOngTC8LOgn/Hpee2qrIQzqSKt0rhAPKJzScahNH0BNn2kTiu0SHGyJG/ih RFnHAUNyLkR3X7P8BvQO0llGCzD80RsTSz8YsbIDwIejInkv89wdGPca4Nz/0CBl5+FEUGaz 2IWOyb1C3tzB7C5QNFtKOLe4lncACEZc3HqrAtAB4PHZElMiLO2+nbovFm9+x6iWTHtHQabh BURnRF3nLt+BkyyzXWaD6Q+UaBjW9oS9REAIdMnj59m0S7KkfoZ5uZ4SV3dwZWxiNyOFsPet 7uCuCv54zRxcNBcCjjgCxKuTsp79RDl6AXNhrELmGm0Fqwa1OsIshkF73wAAAAAAAA== --------------ms070807030402010801000803--