The error, ESTALE, was originally introduced to handle the situation
where a file handle, which NFS uses to uniquely identify a file on the
server, no longer refers to a valid file on the server. This can
happen when the file is removed on the server, either by an
application on the server, some other client accessing the server, or
sometimes even by another mounted file system from the same client.
The NFS server also returns this error when the file resides upon a
file system which is no longer exported. Additionally, some NFS
servers even change the file handle when a file is renamed, although
this practice is discouraged.
This error occurs even if a file or directory, with the same name, is
recreated on the server without the client being aware of it. The
file handle refers to a specific instance of a file and deleting the
file and then recreating it creates a new instance of the file.
The error, ESTALE, is usually seen when cached directory information
is used to convert a pathname to a dentry/inode pair. The information
is discovered to be out of date or stale when a subsequent operation
is sent to the NFS server. This can easily happen in system calls
such as stat(2) when the pathname is converted a dentry/inode pair
using cached information, but then a subsequent GETATTR call to the
server discovers that the file handle is no longer valid.
This error can also occur when a change is made on the server in
between looking up different components of the pathname to be looked
up or between a successful lookup and a subsequent operation.
Original link about ESTALE: ESTALE LWN .
I suggest to you check files and directories on NFS server or say to admin of NFS server to do this.
Maybe some old pagecache, inode, dentry cache entries are exists on NFS server. Please clean it:
# To free pagecache
echo 1 > /proc/sys/vm/drop_caches
# To free dentries and inodes
echo 2 > /proc/sys/vm/drop_caches
# To free pagecache, dentries and inodes
echo 3 > /proc/sys/vm/drop_caches