Lines Matching refs:block

7 It aims to improve performance of a block device (eg, a spindle) by
27   Migration -  Movement of the primary copy of a logical block from one
32 The origin device always contains a copy of the logical block, which
56 Fixed block size
59 The origin is divided up into blocks of a fixed size.  This block size
61 using block sizes of 256KB - 1024KB.  The block size must be between 64
64 Having a fixed block size simplifies the target a lot.  But it is
65 something of a compromise.  For instance, a small part of a block may be
66 getting hit a lot, yet the whole block will be promoted to the cache.
67 So large block sizes are bad because they waste cache space.  And small
68 block sizes are bad because they increase the amount of metadata (both
77 If writeback, the default, is selected then a write to a block that is
78 cached will go only to the cache and the block will be marked dirty in
81 If writethrough is selected then a write to a cached block will not
89 block invalidates.  To enable passthrough mode the cache must be clean.
133 The 'dirty' state for a cache block changes far too frequently for us
138 Per-block policy hints
141 Policy plug-ins can store a chunk of data per cache block.  It's up to
163 We can avoid copying data during migration if we know the block has
165 whole block device.  We store a bitset tracking the discard state of
166 blocks.  However, we allow this bitset to have a different block size
177  cache <metadata dev> <cache dev> <origin dev> <block size>
184  block size      : cache unit size in sectors
197    writethrough  : write through caching that prohibits cache block
198 		   content from being different from origin block content.
200 		   back cache block contents later for performance reasons,
207 		   block, then the cache block is invalidated.
219 <metadata block size> <#used metadata blocks>/<#total metadata blocks>
220 <cache block size> <#used cache blocks>/<#total cache blocks>
226 metadata block size	 : Fixed block size for each metadata block in
230 cache block size	 : Configurable block size for the cache device
242 #demotions		 : Number of times a block has been removed
244 #promotions		 : Number of times a block has been moved to