Some background pool 57 is a new rbd pool (12MiB used) that I was just experimenting with (performance of striped hdd rbd devices), I don't think I deleted it but can't say for sure (it appears in ceph df) since it doesn't matter. This pool was created on reef, a full deep scrub has been done several times over since moving to reef (March 2024), likely no deep scrub has been done since moving to squid since I've had lots of troubles... This error however has broken a 150TiB machine and worse I don't know that a restart won't break others.. After a host reboot I've lost half the OSDs on that host, they all refuse to start with: -725> 2025-09-25T18:02:37.157+0000 7f93d0aab8c0 -1 Falling back to public interface -2> 2025-09-25T18:02:40.033+0000 7f93d0aab8c0 -1 osd.21 2098994 init missing pg_pool_t for deleted pool 57 for pg 57.3s7; please downgrade to luminous and allow pg deletion to complete before upgrading -1> 2025-09-25T18:02:40.037+0000 7f93d0aab8c0 -1 ./src/osd/OSD.cc: In function 'int OSD::init()' thread 7f93d0aab8c0 time 2025-09-25T18:02:40.040491+0000 ./src/osd/OSD.cc: 3867: ceph_abort_msg("abort() called") ceph version 19.2.3 (c92aebb279828e9c3c1f5d24613efca272649e62) squid (stable) 1: (ceph::__ceph_abort(char const*, int, char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)+0xb7) [0x560b78a7056a] 2: /usr/bin/ceph-osd(+0x385bcb) [0x560b789f0bcb] 3: main() 4: /lib/x86_64-linux-gnu/libc.so.6(+0x29d90) [0x7f93d165dd90] 5: __libc_start_main() 6: _start() 0> 2025-09-25T18:02:40.037+0000 7f93d0aab8c0 -1 *** Caught signal (Aborted) ** in thread 7f93d0aab8c0 thread_name:ceph-osd ceph version 19.2.3 (c92aebb279828e9c3c1f5d24613efca272649e62) squid (stable) 1: /lib/x86_64-linux-gnu/libc.so.6(+0x42520) [0x7f93d1676520] 2: pthread_kill() 3: raise() 4: abort() 5: (ceph::__ceph_abort(char const*, int, char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)+0x16a) [0x560b78a7061d] 6: /usr/bin/ceph-osd(+0x385bcb) [0x560b789f0bcb] 7: main() 8: /lib/x86_64-linux-gnu/libc.so.6(+0x29d90) [0x7f93d165dd90] 9: __libc_start_main() 10: _start() NOTE: a copy of the executable, or `objdump -rdS <executable>` is needed to interpret this. -725> 2025-09-25T18:02:37.157+0000 7f93d0aab8c0 -1 Falling back to public interface -2> 2025-09-25T18:02:40.033+0000 7f93d0aab8c0 -1 osd.21 2098994 init missing pg_pool_t for deleted pool 57 for pg 57.3s7; please downgrade to luminous and allow pg deletion to complete before upgrading -1> 2025-09-25T18:02:40.037+0000 7f93d0aab8c0 -1 ./src/osd/OSD.cc: In function 'int OSD::init()' thread 7f93d0aab8c0 time 2025-09-25T18:02:40.040491+0000 ./src/osd/OSD.cc: 3867: ceph_abort_msg("abort() called") ceph version 19.2.3 (c92aebb279828e9c3c1f5d24613efca272649e62) squid (stable) 1: (ceph::__ceph_abort(char const*, int, char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)+0xb7) [0x560b78a7056a] 2: /usr/bin/ceph-osd(+0x385bcb) [0x560b789f0bcb] 3: main() 4: /lib/x86_64-linux-gnu/libc.so.6(+0x29d90) [0x7f93d165dd90] 5: __libc_start_main() 6: _start() 0> 2025-09-25T18:02:40.037+0000 7f93d0aab8c0 -1 *** Caught signal (Aborted) ** in thread 7f93d0aab8c0 thread_name:ceph-osd ceph version 19.2.3 (c92aebb279828e9c3c1f5d24613efca272649e62) squid (stable) 1: /lib/x86_64-linux-gnu/libc.so.6(+0x42520) [0x7f93d1676520] 2: pthread_kill() 3: raise() 4: abort() 5: (ceph::__ceph_abort(char const*, int, char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)+0x16a) [0x560b78a7061d] 6: /usr/bin/ceph-osd(+0x385bcb) [0x560b789f0bcb] 7: main() 8: /lib/x86_64-linux-gnu/libc.so.6(+0x29d90) [0x7f93d165dd90] 9: __libc_start_main() 10: _start() NOTE: a copy of the executable, or `objdump -rdS <executable>` is needed to interpret this. Aborted Will deleting the PG help? Is there any way I can recover these OSDs? Will moving back to reef help? Daniel