Hello Ceph users and readers, I am facing a really unknown situation for me (being kinda new) with a CephFS cluster (Squid 19.2.2, Cephadm) where the data pool is intact (7.2 TB used, 4.9TB stored), inode objects exist in the recovered metadata pool, but when i try to mount the filesystem, its empty. What initially happened is that I had two groups of drives: nvme’s and spinning. I had separate pools for both, and I eventually deleted the nvme’s pool and then removed the nvmes from the machine. I never thought that they had included metadata for spinning rust’s pool, but here we are. Version: 19.2.2 Squid Metadata pool ID 1 (cephfs.cephfs.meta), Size=1 (No Replicas :(, yes I know I messed up). Data Pool ID 6 (ec_data), erasure coded with k=2 m=1. All OSDs are up. 256 PGs are active+clean. there’s then quite a bit that are inconsistent, degraded, undersized, remapped, and other stuff. Here’s what I’ve done since losing the metadata pool due to OSD purges. I tried to rebuild metadata from the data pool by doing: 1. cephfs-data-scan init --force-init 2. cephfs-data-scan scan_extents 3. cephfs-data-scan scan_inodes ceph df shows 7.2 TiB stored in pool ec_data (which is the spinning rust pool) Inodes do exist. running rados -p cephfs.cephfs.meta ls | grep "100." returns tons of objects (ex. 1000005f1f3.00000000). If i try to mount via ceph-fuse, it shows an empty root. there is no lost+found folder either. A big problem is that when I try to link the orphaned inodes to lost+found, the command finishes instantly with no output, as if it believes the cluster is clean. I run: cephfs-data-scan scan_links --filesystem cephfs # and it returns code 0, no output, and runs in <1 second So my final question is since scan_inodes has populated the metadata pool with objects (100.xxxx), but scan_links ignores them, how do I force a re-scan or just do SOMETHING so scan_links will actually link these files into lost+found? All The Best, Enzo