Hi, I try to distribute all top level dirs in CephFS by different MDS ranks. I have two active MDS with rank *0* and *1 *and I have 2 top dirs like */dir1* and* /dir2*. After pinning: setfattr -n ceph.dir.pin -v 0 /fs-mountpoint/dir1 setfattr -n ceph.dir.pin -v 0 /fs-mountpoint/dir2 I can see next INOS and DNS distribution: RANK STATE MDS ACTIVITY DNS INOS DIRS CAPS 0 active c Reqs: 127 /s 12.6k 12.5k 333 505 1 active b Reqs: 11 /s 21 24 19 1 When I write to dir1 I can see a small amount on Reqs: in rank 1. Events in journal of MDS with rank 1: cephfs-journal-tool --rank=fs1:1 event get list 2024-11-20T12:24:42.045056+0300 0xc5c1cb UPDATE: (scatter_writebehind) A2037D53 2024-11-20T12:24:46.935934+0300 0xc5c629 SESSION: () 2024-11-20T12:24:47.192012+0300 0xc5c7cd UPDATE: (lock inest accounted scatter stat update) 2024-11-20T12:24:47.904717+0300 0xc5ca0b SESSION: () 2024-11-20T12:26:46.912719+0300 0xc5ca98 SESSION: () 2024-11-20T12:26:47.910806+0300 0xc5cc3c SESSION: () 2024-11-20T12:27:35.746239+0300 0xc5ccc9 SESSION: () 2024-11-20T12:28:46.923812+0300 0xc5ce63 SESSION: () 2024-11-20T12:28:47.903066+0300 0xc5d007 SESSION: () 2024-11-20T12:29:08.063326+0300 0xc5d094 EXPORT: () di1/A2037D53 2024-11-20T12:30:46.909621+0300 0xc5d96f SESSION: () 2024-11-20T12:30:47.908050+0300 0xc5db13 SESSION: () 2024-11-20T12:32:46.907649+0300 0xc5dba0 SESSION: () 2024-11-20T12:32:47.905962+0300 0xc5dd44 SESSION: () 2024-11-20T12:34:44.349348+0300 0xc5ddd1 SESSIONS: () But the main problem, when I stop MDS rank 1 (without any kind of standby) - FS hangs for all actions. Is this correct? Is it possible to completely exclude rank 1 from processing dir1 and not stop io when rank 1 goes down?