include/linux/drbd_limits.h

   1 /*
   2   drbd_limits.h
   3   This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
   4 */
   5
   6 /*
   7  * Our current limitations.
   8  * Some of them are hard limits,
   9  * some of them are arbitrary range limits, that make it easier to provide
  10  * feedback about nonsense settings for certain configurable values.
  11  */
  12
  13 #ifndef DRBD_LIMITS_H
  14 #define DRBD_LIMITS_H 1
  15
  16 #define DEBUG_RANGE_CHECK 0
  17
  18 #define DRBD_MINOR_COUNT_MIN 1
  19 #define DRBD_MINOR_COUNT_MAX 255
  20
  21 #define DRBD_DIALOG_REFRESH_MIN 0
  22 #define DRBD_DIALOG_REFRESH_MAX 600
  23
  24 /* valid port number */
  25 #define DRBD_PORT_MIN 1
  26 #define DRBD_PORT_MAX 0xffff
  27
  28 /* startup { */
  29   /* if you want more than 3.4 days, disable */
  30 #define DRBD_WFC_TIMEOUT_MIN 0
  31 #define DRBD_WFC_TIMEOUT_MAX 300000
  32 #define DRBD_WFC_TIMEOUT_DEF 0
  33
  34 #define DRBD_DEGR_WFC_TIMEOUT_MIN 0
  35 #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
  36 #define DRBD_DEGR_WFC_TIMEOUT_DEF 0
  37
  38 #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
  39 #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
  40 #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
  41 /* }*/
  42
  43 /* net { */
  44   /* timeout, unit centi seconds
  45    * more than one minute timeout is not usefull */
  46 #define DRBD_TIMEOUT_MIN 1
  47 #define DRBD_TIMEOUT_MAX 600
  48 #define DRBD_TIMEOUT_DEF 60       /* 6 seconds */
  49
  50   /* active connection retries when C_WF_CONNECTION */
  51 #define DRBD_CONNECT_INT_MIN 1
  52 #define DRBD_CONNECT_INT_MAX 120
  53 #define DRBD_CONNECT_INT_DEF 10   /* seconds */
  54
  55   /* keep-alive probes when idle */
  56 #define DRBD_PING_INT_MIN 1
  57 #define DRBD_PING_INT_MAX 120
  58 #define DRBD_PING_INT_DEF 10
  59
  60  /* timeout for the ping packets.*/
  61 #define DRBD_PING_TIMEO_MIN  1
  62 #define DRBD_PING_TIMEO_MAX  100
  63 #define DRBD_PING_TIMEO_DEF  5
  64
  65   /* max number of write requests between write barriers */
  66 #define DRBD_MAX_EPOCH_SIZE_MIN 1
  67 #define DRBD_MAX_EPOCH_SIZE_MAX 20000
  68 #define DRBD_MAX_EPOCH_SIZE_DEF 2048
  69
  70   /* I don't think that a tcp send buffer of more than 10M is usefull */
  71 #define DRBD_SNDBUF_SIZE_MIN  0
  72 #define DRBD_SNDBUF_SIZE_MAX  (10<<20)
  73 #define DRBD_SNDBUF_SIZE_DEF  0
  74
  75 #define DRBD_RCVBUF_SIZE_MIN  0
  76 #define DRBD_RCVBUF_SIZE_MAX  (10<<20)
  77 #define DRBD_RCVBUF_SIZE_DEF  0
  78
  79   /* @4k PageSize -> 128kB - 512MB */
  80 #define DRBD_MAX_BUFFERS_MIN  32
  81 #define DRBD_MAX_BUFFERS_MAX  131072
  82 #define DRBD_MAX_BUFFERS_DEF  2048
  83
  84   /* @4k PageSize -> 4kB - 512MB */
  85 #define DRBD_UNPLUG_WATERMARK_MIN  1
  86 #define DRBD_UNPLUG_WATERMARK_MAX  131072
  87 #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
  88
  89   /* 0 is disabled.
  90    * 200 should be more than enough even for very short timeouts */
  91 #define DRBD_KO_COUNT_MIN  0
  92 #define DRBD_KO_COUNT_MAX  200
  93 #define DRBD_KO_COUNT_DEF  0
  94 /* } */
  95
  96 /* syncer { */
  97   /* FIXME allow rate to be zero? */
  98 #define DRBD_RATE_MIN 1
  99 /* channel bonding 10 GbE, or other hardware */
 100 #define DRBD_RATE_MAX (4 << 20)
 101 #define DRBD_RATE_DEF 250  /* kb/second */
 102
 103   /* less than 7 would hit performance unneccessarily.
 104    * 3833 is the largest prime that still does fit
 105    * into 64 sectors of activity log */
 106 #define DRBD_AL_EXTENTS_MIN  7
 107 #define DRBD_AL_EXTENTS_MAX  3833
 108 #define DRBD_AL_EXTENTS_DEF  127
 109
 110 #define DRBD_AFTER_MIN  -1
 111 #define DRBD_AFTER_MAX  255
 112 #define DRBD_AFTER_DEF  -1
 113
 114 /* } */
 115
 116 /* drbdsetup XY resize -d Z
 117  * you are free to reduce the device size to nothing, if you want to.
 118  * the upper limit with 64bit kernel, enough ram and flexible meta data
 119  * is 16 TB, currently. */
 120 /* DRBD_MAX_SECTORS */
 121 #define DRBD_DISK_SIZE_SECT_MIN  0
 122 #define DRBD_DISK_SIZE_SECT_MAX  (16 * (2LLU << 30))
 123 #define DRBD_DISK_SIZE_SECT_DEF  0 /* = disabled = no user size... */
 124
 125 #define DRBD_ON_IO_ERROR_DEF EP_PASS_ON
 126 #define DRBD_FENCING_DEF FP_DONT_CARE
 127 #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
 128 #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
 129 #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
 130 #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
 131
 132 #define DRBD_MAX_BIO_BVECS_MIN 0
 133 #define DRBD_MAX_BIO_BVECS_MAX 128
 134 #define DRBD_MAX_BIO_BVECS_DEF 0
 135
 136 #undef RANGE
 137 #endif