Re: NFSv4 hangs on 13.3
- Reply: Rick Macklem : "Re: NFSv4 hangs on 13.3"
- In reply to: J David : "NFSv4 hangs on 13.3"
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Date: Fri, 31 May 2024 20:11:20 UTC
On Fri, May 31, 2024 at 12:39 PM J David <j.david.lists@gmail.com> wrote: > > In an attempt to narrow down the problems we have with NFS v4.2, we've > set up a FreeBSD 13.3 server that mirrors some read-only data from our > Linux NFS servers. > > We are still observing occasional hangs on the FreeBSD 13.3 client machines. > > When these hangs occur, anything that touches the mountpoint > (including "umount -N") hangs indefinitely. There is nothing in dmesg. > > The only even slightly informative data I could gather is an "ls > /mount/point" kstack: > > $ sudo procstat -kk 94676 > PID TID COMM TDNAME KSTACK > 94676 976876 ls - mi_switch+0xbf > sleeplk+0xea lockmgr_slock_hard+0x3a5 nfs_lock+0x29 vop_sigdefer+0x2a > _vn_lock+0x47 vfs_cache_root+0x9d vfs_root_sigdefer+0x35 lookup+0x88a > namei+0x24a kern_statat+0xf8 sys_fstatat+0x27 amd64_syscall+0x110 > fast_syscall_common+0xf8 > > During this time, the NFS server continues serving other clients, and > the affected client can access other NFS servers without hanging. > > The "nfsstat -m" for this mountpoint looks like this: > > nfsv4,minorversion=2,oneopenown,tcp,resvport,nconnect=1,hard,cto,nolockd,sec=sys,acdirmin=3,acdirmax=60,acregmin=5,acregmax=60,nametimeo=60,negnametimeo=60,rsize=65536,wsize=65536,readdirsize=65536,readahead=1,wcommitsize=16777216,timeout=120,retrans=2147483647 > > with these mount flags in /etc/fstab: > > ro,nfsv4,minorversion=2,tcp,nosuid,noatime,nolockd,oneopenown > > Is there anything more we can do to help identify this issue? Collect the output of: # ps axHl and # procstat -kk -a What you show above is just a thread waiting for a lock on an NFS vnode. What we need to figure out is what thread is holding the lock on that vnode while waiting for something else. rick > > Thanks for any advice! >