Hi All I've hit a segfault I've not seen before, seems related to ntirpc, please see backtrace: (gdb) bt #0 xdr_putenum (enumv=<error reading variable: Cannot access memory at address 0x0>, xdrs=0x7fd831761490) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/ntirpc/rpc/xdr.h:584 #1 xdr_enum (xdrs=0x7fd831761490, ep=0x0) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/ntirpc/rpc/xdr_inline.h:405 #2 0x0000000000456749 in xdr_nfs_opnum4 (objp=0x0, xdrs=0x7fd831761490) at /usr/src/debug/nfs-ganesha-2.7.3/include/nfsv41.h:8065 #3 xdr_nfs_resop4 (xdrs=0x7fd831761490, objp=0x0) at /usr/src/debug/nfs-ganesha-2.7.3/include/nfsv41.h:8433 #4 0x0000000000458afe in xdr_array_encode (cpp=<optimized out>, sizep=<optimized out>, xdr_elem=0x456730 <xdr_nfs_resop4>, selem=160, maxsize=1024, xdrs=0x7fd831761490) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/ntirpc/rpc/xdr_inline.h:851 #5 xdr_array (xdr_elem=0x456730 <xdr_nfs_resop4>, selem=160, maxsize=1024, sizep=<optimized out>, cpp=<optimized out>, xdrs=0x7fd831761490) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/ntirpc/rpc/xdr_inline.h:894 #6 xdr_COMPOUND4res (xdrs=0x7fd831761490, objp=<optimized out>) at /usr/src/debug/nfs-ganesha-2.7.3/include/nfsv41.h:8779 #7 0x00007fdc0cd0f89b in svc_vc_reply (req=0x7fd831777d30) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/src/svc_vc.c:887 #8 0x0000000000451337 in nfs_rpc_process_request (reqdata=0x7fd831777d30) at /usr/src/debug/nfs-ganesha-2.7.3/MainNFSD/nfs_worker_thread.c:1384 #9 0x0000000000450766 in nfs_rpc_decode_request (xprt=0x7fdb1c00a0d0, xdrs=0x7fd831f6e190) at /usr/src/debug/nfs-ganesha-2.7.3/MainNFSD/nfs_rpc_dispatcher_thread.c:1345 #10 0x00007fdc0cd0d07d in svc_rqst_xprt_task (wpe=0x7fdb1c00a2e8) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/src/svc_rqst.c:769 #11 0x00007fdc0cd0d59a in svc_rqst_epoll_events (n_events=<optimized out>, sr_rec=0x53136a0) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/src/svc_rqst.c:941 #12 svc_rqst_epoll_loop (sr_rec=<optimized out>) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/src/svc_rqst.c:1014 #13 svc_rqst_run_task (wpe=0x53136a0) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/src/svc_rqst.c:1050 #14 0x00007fdc0cd15123 in work_pool_thread (arg=0x7fd86000a960) at /usr/src/debug/nfs-ganesha-2.7.3/libntirpc/src/work_pool.c:181 #15 0x00007fdc0b2cddd5 in start_thread (arg=0x7fdafffff700) at pthread_create.c:307 #16 0x00007fdc0a444ead in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:111 Mem usage on the server was quite high at the time so wonder if that's related? nfs-ganesha-2.7.3-0.1.el7.x86_64 nfs-ganesha-ceph-2.7.3-0.1.el7.x86_64 libcephfs2-14.2.1-0.el7.x86_64 librados2-14.2.1-0.el7.x86_64 Thanks,