FS_GETSERVERPREFS(1)					       AFS Command Reference					      FS_GETSERVERPREFS(1)

NAME

       fs_getserverprefs - Displays preference ranks for file servers or VL servers

SYNOPSIS

       fs getserverprefs [-file <output to named file>]
	   [-numeric] [-vlservers] [-help]

       fs gets [-f <output to named file>] [-n] [-v] [-h]

       fs gp [-f <output to named file>] [-n] [-v] [-h]

DESCRIPTION

       The fs getserverprefs command displays preference ranks for file server machine interfaces (file server machines run the fs process) or, if
       the -vlserver flag is provided, for Volume Location (VL) Server machines (which run the vlserver process). For file server machines, the
       Cache Manager tracks up to 15 interfaces per machine and assigns a separate rank to each interface. The ranks indicate the order in which
       the local Cache Manager attempts to contact the interfaces of machines that are housing a volume when it needs to fetch data from the
       volume. For VL Server machines, the ranks indicate the order in which the Cache Manager attempts to contact a cell's VL Servers when
       requesting VLDB information. For both types of rank, lower integer values are more preferred.

       The Cache Manager stores ranks in kernel memory. Once set, a rank persists until the machine reboots, or until the fs setserverprefs
       command is used to change it. fs_setserverprefs(1) explains how the Cache Manager sets default ranks, and how to use that command to change
       the default values.

       Default VL Server ranks range from 10,000 to 10,126. The Cache Manager assigns ranks to every machine listed in its copy of the
       /etc/openafs/CellServDB file or found via DNS AFSDB or SRV records for the cell when it initializes. When the Cache Manager needs to fetch
       VLDB information from a cell, it compares the ranks for the VL Server machines belonging to that cell, and attempts to contact the VL
       Server with the lowest integer rank. If the Cache Manager cannot reach the VL Server (because of server process, machine or network
       outage), it tries to contact the VL Server with the next lowest integer rank, and so on. If all of a cell's VL Server machines are
       unavailable, the Cache Manager cannot fetch data from the cell.

       Default file server ranks range from 5,000 to 40,000, excluding the range used for VL Servers (10,000 to 10,126); the maximum possible rank
       is 65,534. When the Cache Manager needs to fetch data from a volume, it compares the ranks for the interfaces of machines that house the
       volume, and attempts to contact the interface that has the lowest integer rank. If it cannot reach the fileserver process via that
       interface (because of server process, machine or network outage), it tries to contact the interface with the next lowest integer rank, and
       so on. If it cannot reach any of the interfaces for machines that house the volume, it cannot fetch data from the volume.

       For both file server machines and VL Server machines, it is possible for a machine or interface in a foreign cell to have the same rank as
       a machine or interface in the local cell. This does not present a problem, because the Cache Manager only ever compares ranks for machines
       belonging to one cell at a time.

OPTIONS

       -file <output file>
	   Specifies the full pathname of a file to which to write the preference ranks. If the specified file already exists, the command
	   overwrites its contents. If the pathname is invalid, the command fails. If this argument is not provided, the preference ranks appear
	   on the standard output stream.

       -numeric
	   Displays the IP addresses of file server machine interfaces or VL Server machines, rather than their hostnames. If this argument is not
	   provided, the fs command interpreter has the IP addresses translated to hostnames such as "fs1.abc.com".

       -vlservers
	   Displays preference ranks for VL Server machines rather than file server machine interfaces.

       -help
	   Prints the online help for this command. All other valid options are ignored.

OUTPUT

       The output consists of a separate line for each file server machine interface or VL Server machine, pairing the machine's hostname or IP
       address with its rank. The Cache Manager stores IP addresses in its kernel list of ranks, but the command by default identifies interfaces
       by hostname, by calling a translation routine that refers to either the cell's name service (such as the Domain Name Server) or the local
       host table. If an IP address appears in the output, it is because the translation attempt failed. To bypass the translation step and
       display IP addresses rather than hostnames, include the -numeric flag. This can significantly speed the production of output.

       By default, the command writes to the standard output stream. Use the -file argument to write the output to a file instead.

EXAMPLES

       The following example displays the local Cache Manager's preference ranks for file server machines. The local machine belongs to the AFS
       cell named abc.com, and in this example the ranks of file server machines in its local cell are lower than the ranks of file server
       machines from the foreign cell, "def.com". It is not possible to translate the IP addresses of two machines on the 138.255 network.

	  % fs getserverprefs
	  fs2.abc.com		20007
	  fs3.abc.com		30002
	  fs1.abc.com		20011
	  fs4.abc.com		30010
	  server1.def.com	40002
	  138.255.33.34 	40000
	  server6.def.com	40012
	  138.255.33.37 	40005

       The following example shows hows the output displays IP addresses when the -numeric flag is included, and illustrates how network proximity
       determines default ranks (as described on the fs setserverprefs reference page). The local machine has IP address 192.12.107.210, and the
       two file server machines on its subnetwork have ranks of 20,007 and 20,011. The two file server machines on a different subnetwork of the
       local machine's network have higher ranks, 30,002 and 30,010, whereas the ranks of the remaining machines range from 40,000 to 40,012
       because they are in a completely different network.

	  % fs getserverprefs -numeric
	  192.12.107.214	  20007
	  192.12.105.99 	  30002
	  192.12.107.212	  20011
	  192.12.105.100	  30010
	  138.255.33.41 	  40002
	  138.255.33.34 	  40000
	  138.255.33.36 	  40012
	  138.255.33.37 	  40005

       The example shows how the -vlservers flag displays preference ranks for VL Server machines:

	  % fs getserverprefs -vlservers
	  fs2.abc.com		 10052
	  fs3.abc.com		 10113
	  fs1.abc.com		 10005

PRIVILEGE REQUIRED

       None

SEE ALSO

       fs_setserverprefs(1)

COPYRIGHT

       IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.

       This documentation is covered by the IBM Public License Version 1.0.  It was converted from HTML to POD by software written by Chas
       Williams and Russ Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.

OpenAFS 							    2012-03-26						      FS_GETSERVERPREFS(1)