Multiple nfs clients with the same hostname cause session exceptions, the new client find confirmed nfs4_client by name in the nfsd4_create_session and then will release the se_hash list: old = find_confirmed_client_by_name(&unconf->cl_name, nn); if (old) { status = mark_client_expired_locked(old); if (status) { old = NULL; goto out_free_conn; } trace_nfsd_clid_replaced(&old->cl_clientid); } move_to_confirmed(unconf); Is there any other option, such as IP instead of host name, which is usually unique? Dec 1 22:42:32 dd kernel: nfsd4_exchange_id rqstp=000000006668b520 exid=00000000a44d3b72 clname.len=35 clname.data=000000007b1b5592 ip_addr=192.168.122.130 flags 101, spa_how 0 Dec 1 22:42:32 dd kernel: nfsd4_exchange_id seqid 0 flags 20001 Dec 1 22:42:32 dd kernel: check_slot_seqid enter. seqid 1 slot_seqid 0 Dec 1 22:42:32 dd kernel: alloc_cld_upcall: allocated xid 10 Dec 1 22:42:32 dd rpc.mountd[25713]: v4.2 client attached: 0xe21bb8c66569eeaf from "192.168.122.130:894" Dec 1 22:42:32 dd rpc.mountd[25713]: v4.2 client detached: 0xe21bb8c56569eeaf from "192.168.122.93:791" Dec 1 22:42:32 dd kernel: __find_in_sessionid_hashtbl: 1701441199:3793467590:5:0 Dec 1 22:42:32 dd kernel: nfsd4_sequence: slotid 0 Dec 1 22:42:32 dd kernel: check_slot_seqid enter. seqid 1 slot_seqid 0 Dec 1 22:42:32 dd kernel: nfsd: fh_compose(exp 103:08/128 /, ino=128) Dec 1 22:42:32 dd kernel: --> nfsd4_store_cache_entry slot 000000006ef6f422 Dec 1 22:42:32 dd kernel: __find_in_sessionid_hashtbl: 1701441199:3793467590:5:0 Dec 1 22:42:32 dd kernel: nfsd4_sequence: slotid 0 Dec 1 22:42:32 dd kernel: check_slot_seqid enter. seqid 2 slot_seqid 1 Dec 1 22:42:32 dd kernel: alloc_cld_upcall: allocated xid 11 Dec 1 22:42:32 dd kernel: --> nfsd4_store_cache_entry slot 000000006ef6f422 Dec 1 22:42:36 dd kernel: __find_in_sessionid_hashtbl: 1701441199:3793467589:4:0 Dec 1 22:42:36 dd kernel: __find_in_sessionid_hashtbl: session not found Dec 1 22:42:36 dd kernel: nfsd4_destroy_session: 1701441199:3793467589:4:0 Dec 1 22:42:36 dd kernel: __find_in_sessionid_hashtbl: 1701441199:3793467589:4:0 Dec 1 22:42:36 dd kernel: __find_in_sessionid_hashtbl: session not found Dec 1 22:42:36 dd kernel: nfsd4_exchange_id rqstp=000000006668b520 exid=00000000a44d3b72 clname.len=35 clname.data=000000007b1b5592 ip_addr=192.168.122.93 flags 101, spa_how 0 Dec 1 22:42:36 dd kernel: nfsd4_exchange_id seqid 0 flags 20001 Dec 1 22:42:36 dd kernel: check_slot_seqid enter. seqid 1 slot_seqid 0 Dec 1 22:42:36 dd kernel: alloc_cld_upcall: allocated xid 12 Dec 1 22:42:36 dd rpc.mountd[25713]: v4.2 client attached: 0xe21bb8c76569eeaf from "192.168.122.93:791" Dec 1 22:42:36 dd rpc.mountd[25713]: v4.2 client detached: 0xe21bb8c66569eeaf from "192.168.122.130:894" Dec 1 22:42:36 dd kernel: __find_in_sessionid_hashtbl: 1701441199:3793467591:6:0 Dec 1 22:42:36 dd kernel: nfsd4_sequence: slotid 0 Dec 1 22:42:36 dd kernel: check_slot_seqid enter. seqid 1 slot_seqid 0 Dec 1 22:42:36 dd kernel: nfsd: fh_compose(exp 103:08/128 /, ino=128) Dec 1 22:42:36 dd kernel: --> nfsd4_store_cache_entry slot 00000000e1f66c24 Dec 1 22:42:36 dd kernel: __find_in_sessionid_hashtbl: 1701441199:3793467591:6:0 Dec 1 22:42:36 dd kernel: nfsd4_sequence: slotid 0 Dec 1 22:42:36 dd kernel: check_slot_seqid enter. seqid 2 slot_seqid 1 Dec 1 22:42:36 dd kernel: alloc_cld_upcall: allocated xid 13 Dec 1 22:42:36 dd kernel: --> nfsd4_store_cache_entry slot 00000000e1f66c24 Dec 1 22:43:33 dd kernel: __find_in_sessionid_hashtbl: 1701441199:3793467590:5:0 Dec 1 22:43:33 dd kernel: __find_in_sessionid_hashtbl: session not found Dec 1 22:43:33 dd kernel: nfsd4_destroy_session: 1701441199:3793467590:5:0 Dec 1 22:43:33 dd kernel: __find_in_sessionid_hashtbl: 1701441199:3793467590:5:0 Dec 1 22:43:33 dd kernel: __find_in_sessionid_hashtbl: session not found