aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/block/drbd/Kconfig
diff options
context:
space:
mode:
Diffstat (limited to 'drivers/block/drbd/Kconfig')
-rw-r--r--drivers/block/drbd/Kconfig71
1 files changed, 71 insertions, 0 deletions
diff --git a/drivers/block/drbd/Kconfig b/drivers/block/drbd/Kconfig
new file mode 100644
index 000000000000..f4acd04ebeef
--- /dev/null
+++ b/drivers/block/drbd/Kconfig
@@ -0,0 +1,71 @@
1#
2# DRBD device driver configuration
3#
4
5comment "DRBD disabled because PROC_FS, INET or CONNECTOR not selected"
6 depends on !PROC_FS || !INET || !CONNECTOR
7
8config BLK_DEV_DRBD
9 tristate "DRBD Distributed Replicated Block Device support"
10 depends on PROC_FS && INET && CONNECTOR
11 select LRU_CACHE
12 default n
13 help
14
15 NOTE: In order to authenticate connections you have to select
16 CRYPTO_HMAC and a hash function as well.
17
18 DRBD is a shared-nothing, synchronously replicated block device. It
19 is designed to serve as a building block for high availability
20 clusters and in this context, is a "drop-in" replacement for shared
21 storage. Simplistically, you could see it as a network RAID 1.
22
23 Each minor device has a role, which can be 'primary' or 'secondary'.
24 On the node with the primary device the application is supposed to
25 run and to access the device (/dev/drbdX). Every write is sent to
26 the local 'lower level block device' and, across the network, to the
27 node with the device in 'secondary' state. The secondary device
28 simply writes the data to its lower level block device.
29
30 DRBD can also be used in dual-Primary mode (device writable on both
31 nodes), which means it can exhibit shared disk semantics in a
32 shared-nothing cluster. Needless to say, on top of dual-Primary
33 DRBD utilizing a cluster file system is necessary to maintain for
34 cache coherency.
35
36 For automatic failover you need a cluster manager (e.g. heartbeat).
37 See also: http://www.drbd.org/, http://www.linux-ha.org
38
39 If unsure, say N.
40
41config DRBD_FAULT_INJECTION
42 bool "DRBD fault injection"
43 depends on BLK_DEV_DRBD
44 help
45
46 Say Y here if you want to simulate IO errors, in order to test DRBD's
47 behavior.
48
49 The actual simulation of IO errors is done by writing 3 values to
50 /sys/module/drbd/parameters/
51
52 enable_faults: bitmask of...
53 1 meta data write
54 2 read
55 4 resync data write
56 8 read
57 16 data write
58 32 data read
59 64 read ahead
60 128 kmalloc of bitmap
61 256 allocation of EE (epoch_entries)
62
63 fault_devs: bitmask of minor numbers
64 fault_rate: frequency in percent
65
66 Example: Simulate data write errors on /dev/drbd0 with a probability of 5%.
67 echo 16 > /sys/module/drbd/parameters/enable_faults
68 echo 1 > /sys/module/drbd/parameters/fault_devs
69 echo 5 > /sys/module/drbd/parameters/fault_rate
70
71 If unsure, say N.