{"action":"created","issue":{"url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3950","labels_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3950/labels{/name}","comments_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3950/comments","events_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3950/events","html_url":"https://github.com/zfsonlinux/zfs/issues/3950","id":113158794,"number":3950,"title":"Slow read speed on 0.6.5.3","user":{"login":"OverLocker","id":10357247,"avatar_url":"https://avatars.githubusercontent.com/u/10357247?v=3","gravatar_id":"","url":"https://api.github.com/users/OverLocker","html_url":"https://github.com/OverLocker","followers_url":"https://api.github.com/users/OverLocker/followers","following_url":"https://api.github.com/users/OverLocker/following{/other_user}","gists_url":"https://api.github.com/users/OverLocker/gists{/gist_id}","starred_url":"https://api.github.com/users/OverLocker/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/OverLocker/subscriptions","organizations_url":"https://api.github.com/users/OverLocker/orgs","repos_url":"https://api.github.com/users/OverLocker/repos","events_url":"https://api.github.com/users/OverLocker/events{/privacy}","received_events_url":"https://api.github.com/users/OverLocker/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-10-24T12:55:23Z","updated_at":"2015-10-26T00:27:27Z","closed_at":null,"body":"Hello,\r\nOn Gentoo with 4.0.5 kernel and 0.6.5.3 version of zfs i have slow read speed (50-60MB/s).\r\n\r\nWrite speed is ok - 112MB/s. Disks are not overloaded and CPU and memory is mostly free.\r\n\r\nIts exactly ZFS read speed, because copy speed from single ext4 disk in the same system is 90+ MB/s.\r\n\r\nPool is RaidZ2, 7+2, 3tb disks.\r\n\r\nIs it possible to speed up read perfomance?\r\n\r\n$uname -a\r\nLinux NAS01 4.0.5-gentoo #1 SMP Sat Oct 24 11:32:43 MSK 2015 x86_64 Intel(R) Pentium(R) CPU G630 @ 2.70GHz GenuineIntel GNU/Linux\r\n\r\n # lsb_release -a\r\nLSB Version:    n/a\r\nDistributor ID: Gentoo\r\nDescription:    Gentoo Base System release 2.2\r\nRelease:        2.2\r\nCodename:       n/a\r\n\r\n dmesg | grep -i zfs\r\n[    8.785441] ZFS: Loaded module v0.6.5.3-r0-gentoo, ZFS pool version 5000, ZFS filesystem version 5\r\n\r\n#zpool status\r\n  pool: ZFS01\r\n state: ONLINE\r\n  scan: scrub canceled on Sat Oct 24 15:25:37 2015\r\nconfig:\r\n\r\n        NAME                                          STATE     READ WRITE CKSUM\r\n        ZFS01                                         ONLINE       0     0     0\r\n          raidz2-0                                    ONLINE       0     0     0\r\n            ata-WDC_WD30EFRX-68AX9N0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n            ata-WDC_WD30EFRX-68AX9N0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n            ata-WDC_WD30EZRX-00SPEB0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n            ata-WDC_WD30EZRX-00DC0B0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n            ata-WDC_WD30EZRX-00D8PB0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n            ata-WDC_WD30EZRX-00DC0B0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n            ata-WDC_WD30EZRX-00MMMB0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n            ata-WDC_WD30EZRX-00MMMB0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n            ata-WDC_WD30EFRX-68EUZN0_WD-XXXXXXXXXXX  ONLINE       0     0     0\r\n\r\nerrors: No known data errors\r\n\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/zfsonlinux/zfs/issues/comments/150991573","html_url":"https://github.com/zfsonlinux/zfs/issues/3950#issuecomment-150991573","issue_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3950","id":150991573,"user":{"login":"stevenj","id":764829,"avatar_url":"https://avatars.githubusercontent.com/u/764829?v=3","gravatar_id":"","url":"https://api.github.com/users/stevenj","html_url":"https://github.com/stevenj","followers_url":"https://api.github.com/users/stevenj/followers","following_url":"https://api.github.com/users/stevenj/following{/other_user}","gists_url":"https://api.github.com/users/stevenj/gists{/gist_id}","starred_url":"https://api.github.com/users/stevenj/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/stevenj/subscriptions","organizations_url":"https://api.github.com/users/stevenj/orgs","repos_url":"https://api.github.com/users/stevenj/repos","events_url":"https://api.github.com/users/stevenj/events{/privacy}","received_events_url":"https://api.github.com/users/stevenj/received_events","type":"User","site_admin":false},"created_at":"2015-10-26T00:27:27Z","updated_at":"2015-10-26T00:27:27Z","body":"Can you check if you are getting the same errors in dmesg as me, because I also see the same slow read speeds."}}