Hi, everyone. Recently, when we were doing a massive directory deletion test in which totally 7 million directories are to be removed, we found that the client occasionally receive "ENOSPC" errors while there were still plenty of spare space in the underlying cephfs space. Having read some related source codes, we found that the reason may be that the "STRAY" directories are never fragmented, and when doing our test, the number of stray directories in some of these "STRAY" dirs might reach the limit "mds_bal_fragment_size_max". So we modified the level of output in "Server::check_fragment_space" to 0 and did the test again. And when clients received "ENOSPC", we found lots of logs as the following: 2017-12-18 12:22:31.370524 7f6672fff700 0 mds.0.server fragment [dir 0x603 ~mds0/stray3/ [2,head] auth pv=17728973 v=17497895 cv=17019435/17019435 ap=80055+160110+160110 state=1610645506|complete f(v7 m2017-12-18 12:08:23.017000 55429=0+55429) n(v7 rc2017-12-18 12:08:51.473000 55429=0+55429) hs=55429+121382,ss=0+0 dirty=96756 | child=1 sticky=1 dirty=1 waiter=0 authpin=1 0x7f66652b1080] size exceeds 100000 (ENOSPC) 2017-12-18 12:22:31.370769 7f6672fff700 0 mds.0.server fragment [dir 0x603 ~mds0/stray3/ [2,head] auth pv=17728973 v=17497895 cv=17019435/17019435 ap=80055+160110+160110 state=1610645506|complete f(v7 m2017-12-18 12:08:23.017000 55429=0+55429) n(v7 rc2017-12-18 12:08:51.473000 55429=0+55429) hs=55429+121382,ss=0+0 dirty=96756 | child=1 sticky=1 dirty=1 waiter=0 authpin=1 0x7f66652b1080] size exceeds 100000 (ENOSPC) 2017-12-18 12:22:31.370836 7f6672fff700 0 mds.0.server fragment [dir 0x603 ~mds0/stray3/ [2,head] auth pv=17728973 v=17497895 cv=17019435/17019435 ap=80055+160110+160110 state=1610645506|complete f(v7 m2017-12-18 12:08:23.017000 55429=0+55429) n(v7 rc2017-12-18 12:08:51.473000 55429=0+55429) hs=55429+121382,ss=0+0 dirty=96756 | child=1 sticky=1 dirty=1 waiter=0 authpin=1 0x7f66652b1080] size exceeds 100000 (ENOSPC) 2017-12-18 12:22:31.370907 7f6672fff700 0 mds.0.server fragment [dir 0x603 ~mds0/stray3/ [2,head] auth pv=17728973 v=17497895 cv=17019435/17019435 ap=80055+160110+160110 state=1610645506|complete f(v7 m2017-12-18 12:08:23.017000 55429=0+55429) n(v7 rc2017-12-18 12:08:51.473000 55429=0+55429) hs=55429+121382,ss=0+0 dirty=96756 | child=1 sticky=1 dirty=1 waiter=0 authpin=1 0x7f66652b1080] size exceeds 100000 (ENOSPC) 2017-12-18 12:22:31.370968 7f6672fff700 0 mds.0.server fragment [dir 0x603 ~mds0/stray3/ [2,head] auth pv=17728973 v=17497895 cv=17019435/17019435 ap=80055+160110+160110 state=1610645506|complete f(v7 m2017-12-18 12:08:23.017000 55429=0+55429) n(v7 rc2017-12-18 12:08:51.473000 55429=0+55429) hs=55429+121382,ss=0+0 dirty=96756 | child=1 sticky=1 dirty=1 waiter=0 authpin=1 0x7f66652b1080] size exceeds 100000 (ENOSPC) It seems that our guest is right. Is this by design? Thanks:-) -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
