{"action":"created","issue":{"url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3944","labels_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3944/labels{/name}","comments_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3944/comments","events_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3944/events","html_url":"https://github.com/zfsonlinux/zfs/issues/3944","id":112734051,"number":3944,"title":"txg_sync high IO","user":{"login":"poiuty","id":3885951,"avatar_url":"https://avatars.githubusercontent.com/u/3885951?v=3","gravatar_id":"","url":"https://api.github.com/users/poiuty","html_url":"https://github.com/poiuty","followers_url":"https://api.github.com/users/poiuty/followers","following_url":"https://api.github.com/users/poiuty/following{/other_user}","gists_url":"https://api.github.com/users/poiuty/gists{/gist_id}","starred_url":"https://api.github.com/users/poiuty/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/poiuty/subscriptions","organizations_url":"https://api.github.com/users/poiuty/orgs","repos_url":"https://api.github.com/users/poiuty/repos","events_url":"https://api.github.com/users/poiuty/events{/privacy}","received_events_url":"https://api.github.com/users/poiuty/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":6,"created_at":"2015-10-22T05:31:01Z","updated_at":"2015-10-22T07:57:54Z","closed_at":null,"body":"<del>Please, explain, why when => atime off, I get high IO load from txg_sync (40~60%)?\r\nWhen  => atime on => normal IO txg_sync.</del>\r\n\r\nDebian 8, kernel 3.16.7-ckt11-1+deb8u5 (2015-10-09), zfs-0.6.5.3, qemu-kvm\r\nVMs use raw disk. VM make no IO load. Sometimes txg_sync get 0~100% IO load.\r\n<img =src=\"https://poiuty.com/img/c2/0df2832d0410d8d744f57d4906950dc2.png\">\r\niotop -oPa\r\n<img src=\"https://poiuty.com/img/8c/6eb398152daa8506ffbd88e4db9c968c.png\">\r\n\r\nSomtime it`s work with low IO load.\r\n<img src=\"https://poiuty.com/img/a4/02f07a509c7c57cb9ff3504d2a5004a4.png\">\r\n\r\nMunin\r\n<img src=\"https://poiuty.com/img/1e/bab2414fa4c7766219a41f421300541e.png\">\r\n\r\nperf top\r\n<img src=\"https://poiuty.com/img/6e/4528aae5ebd5917701c0b706ca09b66e.png\">"},"comment":{"url":"https://api.github.com/repos/zfsonlinux/zfs/issues/comments/150137874","html_url":"https://github.com/zfsonlinux/zfs/issues/3944#issuecomment-150137874","issue_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3944","id":150137874,"user":{"login":"Sachiru","id":3443691,"avatar_url":"https://avatars.githubusercontent.com/u/3443691?v=3","gravatar_id":"","url":"https://api.github.com/users/Sachiru","html_url":"https://github.com/Sachiru","followers_url":"https://api.github.com/users/Sachiru/followers","following_url":"https://api.github.com/users/Sachiru/following{/other_user}","gists_url":"https://api.github.com/users/Sachiru/gists{/gist_id}","starred_url":"https://api.github.com/users/Sachiru/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/Sachiru/subscriptions","organizations_url":"https://api.github.com/users/Sachiru/orgs","repos_url":"https://api.github.com/users/Sachiru/repos","events_url":"https://api.github.com/users/Sachiru/events{/privacy}","received_events_url":"https://api.github.com/users/Sachiru/received_events","type":"User","site_admin":false},"created_at":"2015-10-22T07:57:54Z","updated_at":"2015-10-22T07:57:54Z","body":"How is the pool constructed? Additionally, you might be able to get better\nsupport if you go onto the #ZFSOnLinux IRC channel on FreeNode.\n\nThere are 10 kinds of people in the world; those who can read binary and\nthose who can't.\n\nOn Thu, Oct 22, 2015 at 3:56 PM, poiuty <notifications@github.com> wrote:\n\n> Yes, try relatime. Same.\n> compression => no.\n>\n> —\n> Reply to this email directly or view it on GitHub\n> <https://github.com/zfsonlinux/zfs/issues/3944#issuecomment-150137581>.\n>\n"}}