Dear all, This is a small problem. I was not able to figure out the way to open an issue, so I just share it here. After some wrong operation steps (run ceph-osd command using root), I was not be able to start ceph-osd anymore. I can see the following stack in debug log. 2017-03-22 02:23:54.054907 7f0e87d8b940 -1 osd.0 0 failed to load OSD map for epoch 71, got 0 bytes 2017-03-22 02:23:54.056361 7f0e87d8b940 -1 /home/jenkins-build/build/workspace/ceph-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos7/DIST/centos7/MACHINE_SIZE/huge/release/11.2.0/rpm/el7/BUILD/ceph-11.2.0/src/osd/OSD.h: In function 'OSDMapRef OSDService::get_map(epoch_t)' thread 7f0e87d8b940 time 2017-03-22 02:23:54.054921 /home/jenkins-build/build/workspace/ceph-build/ARCH/x86_64/AVAILABLE_ARCH/x86_64/AVAILABLE_DIST/centos7/DIST/centos7/MACHINE_SIZE/huge/release/11.2.0/rpm/el7/BUILD/ceph-11.2.0/src/osd/OSD.h: 997: FAILED assert(ret) ceph version 11.2.0 (f223e27eeb35991352ebc1f67423d4ebc252adb7) 1: (ceph::__ceph_assert_fail(char const*, char const*, int, char const*)+0x85) [0x7f0e88869b35] 2: (OSDService::get_map(unsigned int)+0x3d) [0x7f0e8825d13d] 3: (OSD::init()+0x1fd2) [0x7f0e8820a452] 4: (main()+0x2cda) [0x7f0e8813bf4a] 5: (__libc_start_main()+0xf5) [0x7f0e8460cb15] 6: (()+0x413da9) [0x7f0e881b7da9] After dig this for problem for some time, I finally realize it should a problem of file permission (because of my previous wrong operation). The problem is that there was no tip in debug log. Look at the source code, I guess it's because we do not print file open error debug log in FileStore::lfn_open by default. Please correct me if I am wrong. I'd suggest we can always print error message into debug log. r = ::open((*path)->path(), flags, 0644); if (r < 0) { r = -errno; dout(10) << "error opening file " << (*path)->path() << " with flags=" << flags << ": " << cpp_strerror(-r) << dendl; goto fail; } Thanks Mike -- 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