3 This file is part of DRBD by Philipp Reisner and Lars Ellenberg.
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.
14 #define DRBD_LIMITS_H 1
16 #define DEBUG_RANGE_CHECK 0
18 #define DRBD_MINOR_COUNT_MIN 1
19 #define DRBD_MINOR_COUNT_MAX 256
20 #define DRBD_MINOR_COUNT_DEF 32
22 #define DRBD_VOLUME_MAX 65535
24 #define DRBD_DIALOG_REFRESH_MIN 0
25 #define DRBD_DIALOG_REFRESH_MAX 600
27 /* valid port number */
28 #define DRBD_PORT_MIN 1
29 #define DRBD_PORT_MAX 0xffff
32 /* if you want more than 3.4 days, disable */
33 #define DRBD_WFC_TIMEOUT_MIN 0
34 #define DRBD_WFC_TIMEOUT_MAX 300000
35 #define DRBD_WFC_TIMEOUT_DEF 0
37 #define DRBD_DEGR_WFC_TIMEOUT_MIN 0
38 #define DRBD_DEGR_WFC_TIMEOUT_MAX 300000
39 #define DRBD_DEGR_WFC_TIMEOUT_DEF 0
41 #define DRBD_OUTDATED_WFC_TIMEOUT_MIN 0
42 #define DRBD_OUTDATED_WFC_TIMEOUT_MAX 300000
43 #define DRBD_OUTDATED_WFC_TIMEOUT_DEF 0
47 /* timeout, unit centi seconds
48 * more than one minute timeout is not useful */
49 #define DRBD_TIMEOUT_MIN 1
50 #define DRBD_TIMEOUT_MAX 600
51 #define DRBD_TIMEOUT_DEF 60 /* 6 seconds */
53 /* active connection retries when C_WF_CONNECTION */
54 #define DRBD_CONNECT_INT_MIN 1
55 #define DRBD_CONNECT_INT_MAX 120
56 #define DRBD_CONNECT_INT_DEF 10 /* seconds */
58 /* keep-alive probes when idle */
59 #define DRBD_PING_INT_MIN 1
60 #define DRBD_PING_INT_MAX 120
61 #define DRBD_PING_INT_DEF 10
63 /* timeout for the ping packets.*/
64 #define DRBD_PING_TIMEO_MIN 1
65 #define DRBD_PING_TIMEO_MAX 100
66 #define DRBD_PING_TIMEO_DEF 5
68 /* max number of write requests between write barriers */
69 #define DRBD_MAX_EPOCH_SIZE_MIN 1
70 #define DRBD_MAX_EPOCH_SIZE_MAX 20000
71 #define DRBD_MAX_EPOCH_SIZE_DEF 2048
73 /* I don't think that a tcp send buffer of more than 10M is useful */
74 #define DRBD_SNDBUF_SIZE_MIN 0
75 #define DRBD_SNDBUF_SIZE_MAX (10<<20)
76 #define DRBD_SNDBUF_SIZE_DEF 0
78 #define DRBD_RCVBUF_SIZE_MIN 0
79 #define DRBD_RCVBUF_SIZE_MAX (10<<20)
80 #define DRBD_RCVBUF_SIZE_DEF 0
82 /* @4k PageSize -> 128kB - 512MB */
83 #define DRBD_MAX_BUFFERS_MIN 32
84 #define DRBD_MAX_BUFFERS_MAX 131072
85 #define DRBD_MAX_BUFFERS_DEF 2048
87 /* @4k PageSize -> 4kB - 512MB */
88 #define DRBD_UNPLUG_WATERMARK_MIN 1
89 #define DRBD_UNPLUG_WATERMARK_MAX 131072
90 #define DRBD_UNPLUG_WATERMARK_DEF (DRBD_MAX_BUFFERS_DEF/16)
93 * 200 should be more than enough even for very short timeouts */
94 #define DRBD_KO_COUNT_MIN 0
95 #define DRBD_KO_COUNT_MAX 200
96 #define DRBD_KO_COUNT_DEF 0
100 /* FIXME allow rate to be zero? */
101 #define DRBD_RESYNC_RATE_MIN 1
102 /* channel bonding 10 GbE, or other hardware */
103 #define DRBD_RESYNC_RATE_MAX (4 << 20)
104 #define DRBD_RESYNC_RATE_DEF 250
105 #define DRBD_RESYNC_RATE_SCALE 'k' /* kilobytes */
107 /* less than 7 would hit performance unnecessarily.
108 * 919 slots context information per transaction,
109 * 32k activity log, 4k transaction size,
110 * one transaction in flight:
112 #define DRBD_AL_EXTENTS_MIN 7
113 #define DRBD_AL_EXTENTS_MAX 6433
114 #define DRBD_AL_EXTENTS_DEF 127
116 #define DRBD_RESYNC_AFTER_MIN -1
117 #define DRBD_RESYNC_AFTER_MAX (1<<30)
118 #define DRBD_RESYNC_AFTER_DEF -1
119 #define DRBD_RESYNC_AFTER_SCALE '1'
123 /* drbdsetup XY resize -d Z
124 * you are free to reduce the device size to nothing, if you want to.
125 * the upper limit with 64bit kernel, enough ram and flexible meta data
126 * is 1 PiB, currently. */
127 /* DRBD_MAX_SECTORS */
128 #define DRBD_DISK_SIZE_SECT_MIN 0
129 #define DRBD_DISK_SIZE_SECT_MAX (1 * (2LLU << 40))
130 #define DRBD_DISK_SIZE_SECT_DEF 0 /* = disabled = no user size... */
132 #define DRBD_ON_IO_ERROR_DEF EP_DETACH
133 #define DRBD_FENCING_DEF FP_DONT_CARE
134 #define DRBD_AFTER_SB_0P_DEF ASB_DISCONNECT
135 #define DRBD_AFTER_SB_1P_DEF ASB_DISCONNECT
136 #define DRBD_AFTER_SB_2P_DEF ASB_DISCONNECT
137 #define DRBD_RR_CONFLICT_DEF ASB_DISCONNECT
138 #define DRBD_ON_NO_DATA_DEF OND_IO_ERROR
139 #define DRBD_ON_CONGESTION_DEF OC_BLOCK
141 #define DRBD_MAX_BIO_BVECS_MIN 0
142 #define DRBD_MAX_BIO_BVECS_MAX 128
143 #define DRBD_MAX_BIO_BVECS_DEF 0
145 #define DRBD_C_PLAN_AHEAD_MIN 0
146 #define DRBD_C_PLAN_AHEAD_MAX 300
147 #define DRBD_C_PLAN_AHEAD_DEF 0 /* RS rate controller disabled by default */
149 #define DRBD_C_DELAY_TARGET_MIN 1
150 #define DRBD_C_DELAY_TARGET_MAX 100
151 #define DRBD_C_DELAY_TARGET_DEF 10
153 #define DRBD_C_FILL_TARGET_MIN 0
154 #define DRBD_C_FILL_TARGET_MAX (1<<20) /* 500MByte in sec */
155 #define DRBD_C_FILL_TARGET_DEF 0 /* By default disabled -> controlled by delay_target */
157 #define DRBD_C_MAX_RATE_MIN 250 /* kByte/sec */
158 #define DRBD_C_MAX_RATE_MAX (4 << 20)
159 #define DRBD_C_MAX_RATE_DEF 102400
161 #define DRBD_C_MIN_RATE_MIN 0 /* kByte/sec */
162 #define DRBD_C_MIN_RATE_MAX (4 << 20)
163 #define DRBD_C_MIN_RATE_DEF 4096
165 #define DRBD_CONG_FILL_MIN 0
166 #define DRBD_CONG_FILL_MAX (10<<21) /* 10GByte in sectors */
167 #define DRBD_CONG_FILL_DEF 0
169 #define DRBD_CONG_EXTENTS_MIN DRBD_AL_EXTENTS_MIN
170 #define DRBD_CONG_EXTENTS_MAX DRBD_AL_EXTENTS_MAX
171 #define DRBD_CONG_EXTENTS_DEF DRBD_AL_EXTENTS_DEF
173 #define DRBD_PROTOCOL_DEF DRBD_PROT_C
175 #define DRBD_DISK_BARRIER_DEF 0
176 #define DRBD_DISK_FLUSHES_DEF 1
177 #define DRBD_DISK_DRAIN_DEF 1
178 #define DRBD_MD_FLUSHES_DEF 1
179 #define DRBD_TCP_CORK_DEF 1
181 #define DRBD_ALLOW_TWO_PRIMARIES_DEF 0
182 #define DRBD_ALWAYS_ASBP_DEF 0
183 #define DRBD_USE_RLE_DEF 0