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 256
  20 #define DRBD_MINOR_COUNT_DEF 32
  21
  22 #define DRBD_DIALOG_REFRESH_MIN 0
  23 #define DRBD_DIALOG_REFRESH_MAX 600
  24
  25 /* valid port number */
  26 #define DRBD_PORT_MIN 1
  27 #define DRBD_PORT_MAX 0xffff
  28
  29 /* startup { */
  30   /* if you want more than 3.4 days, disable */
  31 #define DRBD_WFC_TIMEOUT_MIN 0
  32 #define DRBD_WFC_TIMEOUT_MAX 300000
  33 #define DRBD_WFC_TIMEOUT_DEF 0
  34
  35 #define DRBD_DEGR_WFC_TIMEOUT_MIN 0
  36 #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
  37 #define DRBD_DEGR_WFC_TIMEOUT_DEF 0
  38
  39 #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
  40 #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
  41 #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
  42 /* }*/
  43
  44 /* net { */
  45   /* timeout, unit centi seconds
  46    * more than one minute timeout is not useful */
  47 #define DRBD_TIMEOUT_MIN 1
  48 #define DRBD_TIMEOUT_MAX 600
  49 #define DRBD_TIMEOUT_DEF 60       /* 6 seconds */
  50
  51   /* active connection retries when C_WF_CONNECTION */
  52 #define DRBD_CONNECT_INT_MIN 1
  53 #define DRBD_CONNECT_INT_MAX 120
  54 #define DRBD_CONNECT_INT_DEF 10   /* seconds */
  55
  56   /* keep-alive probes when idle */
  57 #define DRBD_PING_INT_MIN 1
  58 #define DRBD_PING_INT_MAX 120
  59 #define DRBD_PING_INT_DEF 10
  60
  61  /* timeout for the ping packets.*/
  62 #define DRBD_PING_TIMEO_MIN  1
  63 #define DRBD_PING_TIMEO_MAX  100
  64 #define DRBD_PING_TIMEO_DEF  5
  65
  66   /* max number of write requests between write barriers */
  67 #define DRBD_MAX_EPOCH_SIZE_MIN 1
  68 #define DRBD_MAX_EPOCH_SIZE_MAX 20000
  69 #define DRBD_MAX_EPOCH_SIZE_DEF 2048
  70
  71   /* I don't think that a tcp send buffer of more than 10M is useful */
  72 #define DRBD_SNDBUF_SIZE_MIN  0
  73 #define DRBD_SNDBUF_SIZE_MAX  (10<<20)
  74 #define DRBD_SNDBUF_SIZE_DEF  0
  75
  76 #define DRBD_RCVBUF_SIZE_MIN  0
  77 #define DRBD_RCVBUF_SIZE_MAX  (10<<20)
  78 #define DRBD_RCVBUF_SIZE_DEF  0
  79
  80   /* @4k PageSize -> 128kB - 512MB */
  81 #define DRBD_MAX_BUFFERS_MIN  32
  82 #define DRBD_MAX_BUFFERS_MAX  131072
  83 #define DRBD_MAX_BUFFERS_DEF  2048
  84
  85   /* @4k PageSize -> 4kB - 512MB */
  86 #define DRBD_UNPLUG_WATERMARK_MIN  1
  87 #define DRBD_UNPLUG_WATERMARK_MAX  131072
  88 #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
  89
  90   /* 0 is disabled.
  91    * 200 should be more than enough even for very short timeouts */
  92 #define DRBD_KO_COUNT_MIN  0
  93 #define DRBD_KO_COUNT_MAX  200
  94 #define DRBD_KO_COUNT_DEF  0
  95 /* } */
  96
  97 /* syncer { */
  98   /* FIXME allow rate to be zero? */
  99 #define DRBD_RATE_MIN 1
 100 /* channel bonding 10 GbE, or other hardware */
 101 #define DRBD_RATE_MAX (4 << 20)
 102 #define DRBD_RATE_DEF 250  /* kb/second */
 103
 104   /* less than 7 would hit performance unnecessarily.
 105    * 3833 is the largest prime that still does fit
 106    * into 64 sectors of activity log */
 107 #define DRBD_AL_EXTENTS_MIN  7
 108 #define DRBD_AL_EXTENTS_MAX  3833
 109 #define DRBD_AL_EXTENTS_DEF  127
 110
 111 #define DRBD_AFTER_MIN  -1
 112 #define DRBD_AFTER_MAX  255
 113 #define DRBD_AFTER_DEF  -1
 114
 115 /* } */
 116
 117 /* drbdsetup XY resize -d Z
 118  * you are free to reduce the device size to nothing, if you want to.
 119  * the upper limit with 64bit kernel, enough ram and flexible meta data
 120  * is 1 PiB, currently. */
 121 /* DRBD_MAX_SECTORS */
 122 #define DRBD_DISK_SIZE_SECT_MIN  0
 123 #define DRBD_DISK_SIZE_SECT_MAX  (1 * (2LLU << 40))
 124 #define DRBD_DISK_SIZE_SECT_DEF  0 /* = disabled = no user size... */
 125
 126 #define DRBD_ON_IO_ERROR_DEF EP_PASS_ON
 127 #define DRBD_FENCING_DEF FP_DONT_CARE
 128 #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
 129 #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
 130 #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
 131 #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
 132 #define DRBD_ON_NO_DATA_DEF OND_IO_ERROR
 133 #define DRBD_ON_CONGESTION_DEF OC_BLOCK
 134
 135 #define DRBD_MAX_BIO_BVECS_MIN 0
 136 #define DRBD_MAX_BIO_BVECS_MAX 128
 137 #define DRBD_MAX_BIO_BVECS_DEF 0
 138
 139 #define DRBD_C_PLAN_AHEAD_MIN  0
 140 #define DRBD_C_PLAN_AHEAD_MAX  300
 141 #define DRBD_C_PLAN_AHEAD_DEF  0 /* RS rate controller disabled by default */
 142
 143 #define DRBD_C_DELAY_TARGET_MIN 1
 144 #define DRBD_C_DELAY_TARGET_MAX 100
 145 #define DRBD_C_DELAY_TARGET_DEF 10
 146
 147 #define DRBD_C_FILL_TARGET_MIN 0
 148 #define DRBD_C_FILL_TARGET_MAX (1<<20) /* 500MByte in sec */
 149 #define DRBD_C_FILL_TARGET_DEF 0 /* By default disabled -> controlled by delay_target */
 150
 151 #define DRBD_C_MAX_RATE_MIN     250 /* kByte/sec */
 152 #define DRBD_C_MAX_RATE_MAX     (4 << 20)
 153 #define DRBD_C_MAX_RATE_DEF     102400
 154
 155 #define DRBD_C_MIN_RATE_MIN     0 /* kByte/sec */
 156 #define DRBD_C_MIN_RATE_MAX     (4 << 20)
 157 #define DRBD_C_MIN_RATE_DEF     4096
 158
 159 #define DRBD_CONG_FILL_MIN      0
 160 #define DRBD_CONG_FILL_MAX      (10<<21) /* 10GByte in sectors */
 161 #define DRBD_CONG_FILL_DEF      0
 162
 163 #define DRBD_CONG_EXTENTS_MIN   DRBD_AL_EXTENTS_MIN
 164 #define DRBD_CONG_EXTENTS_MAX   DRBD_AL_EXTENTS_MAX
 165 #define DRBD_CONG_EXTENTS_DEF   DRBD_AL_EXTENTS_DEF
 166
 167 #undef RANGE
 168 #endif