{"action":"created","issue":{"url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3793","labels_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3793/labels{/name}","comments_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3793/comments","events_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3793/events","html_url":"https://github.com/zfsonlinux/zfs/issues/3793","id":107012531,"number":3793,"title":"0.6.5 iSCSI target very slow and unresponsive","user":{"login":"alexanderhaensch","id":1120164,"avatar_url":"https://avatars.githubusercontent.com/u/1120164?v=3","gravatar_id":"","url":"https://api.github.com/users/alexanderhaensch","html_url":"https://github.com/alexanderhaensch","followers_url":"https://api.github.com/users/alexanderhaensch/followers","following_url":"https://api.github.com/users/alexanderhaensch/following{/other_user}","gists_url":"https://api.github.com/users/alexanderhaensch/gists{/gist_id}","starred_url":"https://api.github.com/users/alexanderhaensch/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/alexanderhaensch/subscriptions","organizations_url":"https://api.github.com/users/alexanderhaensch/orgs","repos_url":"https://api.github.com/users/alexanderhaensch/repos","events_url":"https://api.github.com/users/alexanderhaensch/events{/privacy}","received_events_url":"https://api.github.com/users/alexanderhaensch/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/zfsonlinux/zfs/labels/Performance","name":"Performance","color":"DDDDDD"}],"state":"open","locked":false,"assignee":null,"milestone":{"url":"https://api.github.com/repos/zfsonlinux/zfs/milestones/11","html_url":"https://github.com/zfsonlinux/zfs/milestones/0.7.0","labels_url":"https://api.github.com/repos/zfsonlinux/zfs/milestones/11/labels","id":7013,"number":11,"title":"0.7.0","description":"ZFS on Linux v0.7.0 - Memory management\r\n\r\n","creator":{"login":"behlendorf","id":148917,"avatar_url":"https://avatars.githubusercontent.com/u/148917?v=3","gravatar_id":"","url":"https://api.github.com/users/behlendorf","html_url":"https://github.com/behlendorf","followers_url":"https://api.github.com/users/behlendorf/followers","following_url":"https://api.github.com/users/behlendorf/following{/other_user}","gists_url":"https://api.github.com/users/behlendorf/gists{/gist_id}","starred_url":"https://api.github.com/users/behlendorf/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/behlendorf/subscriptions","organizations_url":"https://api.github.com/users/behlendorf/orgs","repos_url":"https://api.github.com/users/behlendorf/repos","events_url":"https://api.github.com/users/behlendorf/events{/privacy}","received_events_url":"https://api.github.com/users/behlendorf/received_events","type":"User","site_admin":false},"open_issues":153,"closed_issues":116,"state":"open","created_at":"2011-05-03T17:38:46Z","updated_at":"2015-09-23T16:01:39Z","due_on":null,"closed_at":null},"comments":6,"created_at":"2015-09-17T15:37:47Z","updated_at":"2015-09-23T16:21:32Z","closed_at":null,"body":"The iSCSI target used by VMware esxi seems to work but the performance is so slow that the virtual machines running become unresponsive and boot very slowly.\r\ndmesg is full of errors like this:\r\n[11334.299177] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x0000004c\r\n[11334.299466] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x0000004d\r\n[11334.299769] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x0000004e\r\n[11334.299967] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x0000004f\r\n[11334.300269] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x00000050\r\n[11334.301068] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x00000051\r\n[11334.301734] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x00000052\r\n[11334.301898] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x00000053\r\n[11334.302409] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x00000054\r\n[11347.641513] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x00000055\r\n[11347.642172] ABORT_TASK: Found referenced iSCSI task_tag: 731579\r\n[11347.642176] ABORT_TASK: Sending TMR_FUNCTION_COMPLETE for ref_tag: 731579\r\n[11347.642179] ABORT_TASK: Found referenced iSCSI task_tag: 731577\r\n[11347.642179] ABORT_TASK: ref_tag: 731577 already complete, skipping\r\n[11347.642180] ABORT_TASK: Sending TMR_TASK_DOES_NOT_EXIST for ref_tag: 731577\r\n[11361.245366] TARGET_CORE[iSCSI]: Detected NON_EXISTENT_LUN Access for 0x0000005e\r\n[11361.245701] Unexpected ret: -32 send data 48\r\n\r\nreverted to 0.6.4.2 to resolve the issue.\r\n\r\n**uname -a**\r\nLinux io 3.14.51-hardened #1 SMP Thu Sep 17 12:21:09 CEST 2015 x86_64 Intel(R) Xeon(R) CPU E5-2620 v2 @ 2.10GHz GenuineIntel GNU/Linux\r\n\r\n"},"comment":{"url":"https://api.github.com/repos/zfsonlinux/zfs/issues/comments/142652932","html_url":"https://github.com/zfsonlinux/zfs/issues/3793#issuecomment-142652932","issue_url":"https://api.github.com/repos/zfsonlinux/zfs/issues/3793","id":142652932,"user":{"login":"behlendorf","id":148917,"avatar_url":"https://avatars.githubusercontent.com/u/148917?v=3","gravatar_id":"","url":"https://api.github.com/users/behlendorf","html_url":"https://github.com/behlendorf","followers_url":"https://api.github.com/users/behlendorf/followers","following_url":"https://api.github.com/users/behlendorf/following{/other_user}","gists_url":"https://api.github.com/users/behlendorf/gists{/gist_id}","starred_url":"https://api.github.com/users/behlendorf/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/behlendorf/subscriptions","organizations_url":"https://api.github.com/users/behlendorf/orgs","repos_url":"https://api.github.com/users/behlendorf/repos","events_url":"https://api.github.com/users/behlendorf/events{/privacy}","received_events_url":"https://api.github.com/users/behlendorf/received_events","type":"User","site_admin":false},"created_at":"2015-09-23T16:21:32Z","updated_at":"2015-09-23T16:21:32Z","body":"@alexanderhaensch many clustered filesystems behave this way which is why their performance can leave a lot to be desired.  Adding a ZIL device, even a middle-of-the-road SSD, should help considerably.  Until we get to the root cause you may want to leave your systems at 0.6.4.2 if they don't exhibit the issue.   \r\n\r\nThe fsync(2) issue referenced is #3780."}}