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authorMike Snitzer <snitzer@redhat.com>2013-08-16 18:54:19 +0400
committerMike Snitzer <snitzer@redhat.com>2013-08-23 17:02:13 +0400
commit054730446315d2a9a41f4232ebf1d5034244d054 (patch)
treeeefe6fe46fc3d389932bcac4988d9a253649f599 /Documentation/device-mapper/cache.txt
parent66bb2644cac8b5cc1cc477959aa37dcfe6317a23 (diff)
downloadlinux-054730446315d2a9a41f4232ebf1d5034244d054.tar.xz
dm cache: add data block size limits to code and Documentation
Place upper bound on the cache's data block size (1GB). Inform users that the data block size can't be any arbitrary number, i.e. its value must be between 32KB and 1GB. Also, it should be a multiple of 32KB. Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com>
Diffstat (limited to 'Documentation/device-mapper/cache.txt')
-rw-r--r--Documentation/device-mapper/cache.txt3
1 files changed, 2 insertions, 1 deletions
diff --git a/Documentation/device-mapper/cache.txt b/Documentation/device-mapper/cache.txt
index af99c458c841..33d45ee0b737 100644
--- a/Documentation/device-mapper/cache.txt
+++ b/Documentation/device-mapper/cache.txt
@@ -58,7 +58,8 @@ Fixed block size
The origin is divided up into blocks of a fixed size. This block size
is configurable when you first create the cache. Typically we've been
-using block sizes of 256k - 1024k.
+using block sizes of 256KB - 1024KB. The block size must be between 64
+(32KB) and 2097152 (1GB) and a multiple of 64 (32KB).
Having a fixed block size simplifies the target a lot. But it is
something of a compromise. For instance, a small part of a block may be