fixmount [-q] [-a -d -e] [-v [-h hostname_or_IP ] -r -A] [-f] nfs_server ...
Communicates with the NFS mount daemon, mountd , to remove invalid records of client mounts from the NFS server. fixmount is run from the client, and when called without flags, prints the client's IP address to standard output if the server has a record of NFS mounts from the client.
mountd maintains records of which clients have mounted exports from the server, and writes the records to a file so that this information is retained through process or system restarts. (On most Unix platforms, this file is /etc/rmtab ; on Mac OS X, it's /var/db/mountdtab .) Over time, this file accumulates a lot of outdated information, primarily due to clients rebooting or otherwise dropping their mounts without properly informing the server, or changing their hostnames.
The primary purpose of fixmount is to clear bogus entries from the file kept by mountd . On most Unix systems, it does this by comparing the current set of mounts on the client (as listed in /etc/mtab ) to the server's list of mounts from the client, and asking the server's mountd to remove any entries that don't match up.
However, a Mac OS X system keeps a current list of mounts in the kernel, and doesn't use /etc/mtab . Therefore, when fixmount checks this file and finds it empty (or nonexistent), it perceives all of the server's entries as boguseven those that do match up to current mounts on the client. This makes fixmount , at least as currently implemented, of very limited utility on Mac OS X.
Lists mounts from the client in the form IP_addr : pathname . This option is similar to showmount -a , but limited to providing information about the client on which fixmount is run.
Removes all of the entries for the client from the server's /var/db/mountdtab .
Lists exports that are mounted on the client, instead of the client's IP address. This option is similar to showmount -d , but limited to providing information about the client on which fixmount is run.
Prints the server's list of NFS exports to standard output. This option is the same as showmount -e .
Forces all entries for the client to be interpreted as bogus. This option makes - f -r equivalent to - A . On a Mac OS X client, it's as if this flag is always set.
Communicates with the server's mountd as if the client's hostname or IP address were that given by the argument to this option. This option is useful when the client has changed its hostname or IP address, but the server retains invalid entries with the old information.
Minimizes output from error messages.
Removes bogus entries for the client from the server's /var/db/mountdtab .
Runs the verification procedure to determine the list of bogus entries for the client (which is printed to standard output), but doesn't actually remove anything from the server's /var/db/mountdtab .