Hi,
Is there a particular reason why CHUNK_SIZE_MAX is set to 512 sectors in
the dm raid4/5 module? I have a fakeraid controller that can create
rather huge (1MB!) RAID5 stripes that this module rejects. I set it to
2048 and as far as I can tell there haven't been any adverse stability
effects, though I suspect that gigantic stripes do wonders for disk
throughput. :P
Attached is a patch to increase it to 2048 sectors. Please apply if
it's ok.
--D
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
--- a/drivers/md/dm-raid4-5.c 2006-06-01 17:42:27.000000000 -0700
+++ b/drivers/md/dm-raid4-5.c 2006-06-01 17:42:32.000000000 -0700
@@ -70,7 +70,7 @@
#define CHUNK_SIZE 64
/* Maximum setable chunk size in sectors */
-#define CHUNK_SIZE_MAX 512
+#define CHUNK_SIZE_MAX 2048
/* Recover chunk size in sectors */
#define RECOVER_CHUNK_SIZE CHUNK_SIZE_MAX
@@ -3114,7 +3114,7 @@ static int raid_ctr(struct dm_target *ti
chunk_size > CHUNK_SIZE_MAX ||
chunk_size & (chunk_size - 1))
TI_ERR("Invalid chunk size; must "
- "be 2^^n and less equal 512");
+ "be 2^^n and less equal 2048");
/*
* In case we've got 2 or more variable raid parameters,
--- a/drivers/md/dm-raid4-5.c 2006-06-01 17:42:27.000000000 -0700
+++ b/drivers/md/dm-raid4-5.c 2006-06-01 17:42:32.000000000 -0700
@@ -70,7 +70,7 @@
#define CHUNK_SIZE 64
/* Maximum setable chunk size in sectors */
-#define CHUNK_SIZE_MAX 512
+#define CHUNK_SIZE_MAX 2048
/* Recover chunk size in sectors */
#define RECOVER_CHUNK_SIZE CHUNK_SIZE_MAX
@@ -3114,7 +3114,7 @@ static int raid_ctr(struct dm_target *ti
chunk_size > CHUNK_SIZE_MAX ||
chunk_size & (chunk_size - 1))
TI_ERR("Invalid chunk size; must "
- "be 2^^n and less equal 512");
+ "be 2^^n and less equal 2048");
/*
* In case we've got 2 or more variable raid parameters,
--
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