diff options
| author | Lars Ellenberg <lars.ellenberg@linbit.com> | 2014-03-18 15:30:09 +0400 |
|---|---|---|
| committer | Philipp Reisner <philipp.reisner@linbit.com> | 2014-07-10 20:35:00 +0400 |
| commit | aaaba34576407857f6146ff6c330f06e63fb2bf2 (patch) | |
| tree | 6cd468ecb123314d06c641185410f6cbce58c504 /include/linux/drbd_limits.h | |
| parent | 6a8d68b1878e8839b4927150da236c8248703c70 (diff) | |
| download | linux-aaaba34576407857f6146ff6c330f06e63fb2bf2.tar.xz | |
drbd: implement csums-after-crash-only
Checksum based resync trades CPU cycles for network bandwidth,
in situations where we expect much of the to-be-resynced blocks
to be actually identical on both sides already.
In a "network hickup" scenario, it won't help:
all to-be-resynced blocks will typically be different.
The use case is for the resync of *potentially* different blocks
after crash recovery -- the crash recovery had marked larger areas
(those covered by the activity log) as need-to-be-resynced,
just in case. Most of those blocks will be identical.
This option makes it possible to configure checksum based resync,
but only actually use it for the first resync after primary crash.
Signed-off-by: Philipp Reisner <philipp.reisner@linbit.com>
Signed-off-by: Lars Ellenberg <lars.ellenberg@linbit.com>
Diffstat (limited to 'include/linux/drbd_limits.h')
| -rw-r--r-- | include/linux/drbd_limits.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/include/linux/drbd_limits.h b/include/linux/drbd_limits.h index 17e50bb00521..9d2df1d51414 100644 --- a/include/linux/drbd_limits.h +++ b/include/linux/drbd_limits.h @@ -214,6 +214,7 @@ #define DRBD_ALLOW_TWO_PRIMARIES_DEF 0 #define DRBD_ALWAYS_ASBP_DEF 0 #define DRBD_USE_RLE_DEF 1 +#define DRBD_CSUMS_AFTER_CRASH_ONLY_DEF 0 #define DRBD_AL_STRIPES_MIN 1 #define DRBD_AL_STRIPES_MAX 1024 |