3 fs getserverprefs - Displays preference ranks for file servers or VL servers
7 B<fs getserverprefs> [B<-file> <I<output to named file>>]
8 [B<-numeric>] [B<-vlservers>] [B<-help>]
10 B<fs gets> [B<-f> <I<output to named file>>] [B<-n>] [B<-v>] [B<-h>]
12 B<fs gp> [B<-f> <I<output to named file>>] [B<-n>] [B<-v>] [B<-h>]
16 The B<fs getserverprefs> command displays preference ranks for file server
17 machine interfaces (file server machines run the B<fs> process) or, if the
18 B<-vlserver> flag is provided, for Volume Location (VL) Server machines
19 (which run the B<vlserver> process). For file server machines, the Cache
20 Manager tracks up to 15 interfaces per machine and assigns a separate rank
21 to each interface. The ranks indicate the order in which the local Cache
22 Manager attempts to contact the interfaces of machines that are housing a
23 volume when it needs to fetch data from the volume. For VL Server
24 machines, the ranks indicate the order in which the Cache Manager attempts
25 to contact a cell's VL Servers when requesting VLDB information. For both
26 types of rank, lower integer values are more preferred.
28 The Cache Manager stores ranks in kernel memory. Once set, a rank persists
29 until the machine reboots, or until the B<fs setserverprefs> command is
30 used to change it. The reference page for the B<fs setserverprefs> command
31 explains how the Cache Manager sets default ranks, and how to use that
32 command to change the default values.
34 Default VL Server ranks range from 10,000 to 10,126, and the Cache Manager
35 assigns them to every machine listed in its copy of the
36 F</usr/vice/etc/CellServDB> file. When the Cache Manager needs to fetch
37 VLDB information from a cell, it compares the ranks for the VL Server
38 machines belonging to that cell, and attempts to contact the VL Server
39 with the lowest integer rank. If the Cache Manager cannot reach the VL
40 Server (because of server process, machine or network outage), it tries to
41 contact the VL Server with the next lowest integer rank, and so on. If all
42 of a cell's VL Server machines are unavailable, the Cache Manager cannot
43 fetch data from the cell.
45 Default file server ranks range from 5,000 to 40,000, excluding the range
46 used for VL Servers (10,000 to 10,126); the maximum possible rank is
47 65,534. When the Cache Manager needs to fetch data from a volume, it
48 compares the ranks for the interfaces of machines that house the volume,
49 and attempts to contact the interface that has the lowest integer rank. If
50 it cannot reach the B<fileserver> process via that interface (because of
51 server process, machine or network outage), it tries to contact the
52 interface with the next lowest integer rank, and so on. If it cannot reach
53 any of the interfaces for machines that house the volume, it cannot fetch
56 For both file server machines and VL Server machines, it is possible for a
57 machine or interface in a foreign cell to have the same rank as a machine
58 or interface in the local cell. This does not present a problem, because
59 the Cache Manager only ever compares ranks for machines belonging to one
66 =item B<-file> <I<output file>>
68 Specifies the full pathname of a file to which to write the preference
69 ranks. If the specified file already exists, the command overwrites its
70 contents. If the pathname is invalid, the command fails. If this argument
71 is not provided, the preference ranks appear on the standard output
76 Displays the IP addresses of file server machine interfaces or VL Server
77 machines, rather than their hostnames. If this argument is not provided,
78 the B<fs> command interpreter has the IP addresses translated to hostnames
79 such as C<fs1.abc.com>.
83 Displays preference ranks for VL Server machines rather than file server
88 Prints the online help for this command. All other valid options are
95 The output consists of a separate line for each file server machine
96 interface or VL Server machine, pairing the machine's hostname or IP
97 address with its rank. The Cache Manager stores IP addresses in its kernel
98 list of ranks, but the command by default identifies interfaces by
99 hostname, by calling a translation routine that refers to either the
100 cell's name service (such as the Domain Name Server) or the local host
101 table. If an IP address appears in the output, it is because the
102 translation attempt failed. To bypass the translation step and display IP
103 addresses rather than hostnames, include the B<-numeric> flag. This can
104 significantly speed the production of output.
106 By default, the command writes to the standard output stream. Use the
107 B<-file> argument to write the output to a file instead.
111 The following example displays the local Cache Manager's preference ranks
112 for file server machines. The local machine belongs to the AFS cell named
113 B<abc.com>, and in this example the ranks of file server machines in its
114 local cell are lower than the ranks of file server machines from the
115 foreign cell, C<def.com>. It is not possible to translate the IP addresses
116 of two machines on the 138.255 network.
123 server1.def.com 40002
125 server6.def.com 40012
128 The following example shows hows the output displays IP addresses when the
129 B<-numeric> flag is included, and illustrates how network proximity
130 determines default ranks (as described on the B<fs setserverprefs>
131 reference page). The local machine has IP address 192.12.107.210, and the
132 two file server machines on its subnetwork have ranks of 20,007 and
133 20,011. The two file server machines on a different subnetwork of the
134 local machine's network have higher ranks, 30,002 and 30,010, whereas the
135 ranks of the remaining machines range from 40,000 to 40,012 because they
136 are in a completely different network.
138 % fs getserverprefs -numeric
148 The example shows how the B<-vlservers> flag displays preference ranks for
151 % fs getserverprefs -vlservers
156 =head1 PRIVILEGE REQUIRED
162 L<fs_setserverprefs(1)>
166 IBM Corporation 2000. <http://www.ibm.com/> All Rights Reserved.
168 This documentation is covered by the IBM Public License Version 1.0. It was
169 converted from HTML to POD by software written by Chas Williams and Russ
170 Allbery, based on work by Alf Wachsmann and Elizabeth Cassell.