doc/man-pages/pod8/fragments/fileserver-description.pod

   1 The File Server creates the F</usr/afs/logs/FileLog> log file as it
   2 initializes, if the file does not already exist. It does not write a
   3 detailed trace by default, but the B<-d> option may be used to
   4 increase the amount of detail. Use the B<bos getlog> command to
   5 display the contents of the log file.
   6
   7 The command's arguments enable the administrator to control many aspects
   8 of the File Server's performance, as detailed in L</OPTIONS>.  By default
   9 the File Server sets values for many arguments that are suitable
  10 for a medium-sized file server machine. To set values suitable for a small
  11 or large file server machine, use the B<-S> or B<-L> flag
  12 respectively. The following list describes the parameters and
  13 corresponding argument for which the File Server sets default
  14 values, and the table below summarizes the setting for each of the three
  15 machine sizes.
  16
  17 =over 4
  18
  19 =item *
  20
  21 The maximum number of threads
  22 the File Server uses to handle requests for data; corresponds to the
  23 B<-p> argument. The File Server always uses a minimum of 32 KB of
  24 memory for these processes.
  25
  26 =item *
  27
  28 The maximum number of directory blocks the File Server caches in memory;
  29 corresponds to the B<-b> argument. Each cached directory block (buffer)
  30 consumes 2,092 bytes of memory.
  31
  32 =item *
  33
  34 The maximum number of large vnodes the File Server caches in memory for
  35 tracking directory elements; corresponds to the B<-l> argument. Each large
  36 vnode consumes 292 bytes of memory.
  37
  38 =item *
  39
  40 The maximum number of small vnodes the File Server caches in memory for
  41 tracking file elements; corresponds to the B<-s> argument.  Each small
  42 vnode consumes 100 bytes of memory.
  43
  44 =item *
  45
  46 The maximum volume cache size, which determines how many volumes the File
  47 Server can cache in memory before having to retrieve data from disk;
  48 corresponds to the B<-vc> argument.
  49
  50 =item *
  51
  52 The maximum number of callback structures the File Server caches in
  53 memory; corresponds to the B<-cb> argument. Each callback structure
  54 consumes 16 bytes of memory.
  55
  56 =item *
  57
  58 The maximum number of Rx packets the File Server uses; corresponds to the
  59 B<-rxpck> argument. Each packet consumes 1544 bytes of memory.
  60
  61 =back
  62
  63 The default values are:
  64
  65   Parameter (Argument)               Small (-S)     Medium   Large (-L)
  66   ---------------------------------------------------------------------
  67   Number of threads (-p)                     6           9          128
  68   Number of cached dir blocks (-b)          70          90          120
  69   Number of cached large vnodes (-l)       200         400          600
  70   Number of cached small vnodes (-s)       200         400          600
  71   Maximum volume cache size (-vc)          200         400          600
  72   Number of callbacks (-cb)             20,000      60,000       64,000
  73   Number of Rx packets (-rxpck)            100         150          200
  74
  75 To override any of the values, provide the indicated argument (which can
  76 be combined with the B<-S> or B<-L> flag).
  77
  78 The amount of memory required for the File Server varies. The approximate
  79 default memory usage is 751 KB when the B<-S> flag is used (small
  80 configuration), 1.1 MB when all defaults are used (medium configuration),
  81 and 1.4 MB when the B<-L> flag is used (large configuration). If
  82 additional memory is available, increasing the value of the B<-cb> and
  83 B<-vc> arguments can improve File Server performance most directly.
  84
  85 By default, the File Server allows a volume to exceed its quota by 1 MB
  86 when an application is writing data to an existing file in a volume that
  87 is full. The File Server still does not allow users to create new files in
  88 a full volume. To change the default, use one of the following arguments:
  89
  90 =over 4
  91
  92 =item *
  93
  94 Set the B<-spare> argument to the number of extra kilobytes that the File
  95 Server allows as overage. A value of C<0> allows no overage.
  96
  97 =item *
  98
  99 Set the B<-pctspare> argument to the percentage of the volume's quota the
 100 File Server allows as overage.
 101
 102 =back
 103
 104 By default, the File Server implicitly grants the C<a> (administer) and
 105 C<l> (lookup) permissions to system:administrators on the access control
 106 list (ACL) of every directory in the volumes stored on its file server
 107 machine. In other words, the group's members can exercise those two
 108 permissions even when an entry for the group does not appear on an ACL. To
 109 change the set of default permissions, use the B<-implicit> argument.
 110
 111 The File Server maintains a I<host current protection subgroup> (I<host
 112 CPS>) for each client machine from which it has received a data access
 113 request. Like the CPS for a user, a host CPS lists all of the Protection
 114 Database groups to which the machine belongs, and the File Server compares
 115 the host CPS to a directory's ACL to determine in what manner users on the
 116 machine are authorized to access the directory's contents. When the B<pts
 117 adduser> or B<pts removeuser> command is used to change the groups to
 118 which a machine belongs, the File Server must recompute the machine's host
 119 CPS in order to notice the change. By default, the File Server contacts
 120 the Protection Server every two hours to recompute host CPSs, implying
 121 that it can take that long for changed group memberships to become
 122 effective. To change this frequency, use the B<-hr> argument.
 123
 124 The File Server stores volumes in partitions. A partition is a
 125 filesystem or directory on the server machine that is named C</vicepX>
 126 or C</vicepXX> where XX is "a" through "z" or "aa" though "iv". Up to
 127 255 partitions are allowed. The File Server expects that the /vicepXX
 128 directories are each on a dedicated filesystem. The File Server will
 129 only use a /vicepXX if it's a mountpoint for another filesystem,
 130 unless the file C</vicepXX/AlwaysAttach> exists.  A partition will not be
 131 mounted if the file C</vicepXX/NeverAttach> exists. If both
 132 C</vicepXX/AlwaysAttach> and C</vicepXX/NeverAttach> are present, then
 133 C</vicepXX/AlwaysAttach> wins.  The data in the partition is a special
 134 format that can only be access using OpenAFS commands or an OpenAFS
 135 client.
 136
 137 The File Server generates the following message when a partition is nearly
 138 full:
 139
 140    No space left on device
 141
 142 This command does not use the syntax conventions of the AFS command
 143 suites. Provide the command name and all option names in full.