Lines Matching refs:of
7 It aims to improve performance of a block device (eg, a spindle) by
8 dynamically migrating some of its data to a faster, smaller device
12 different levels of the dm stack, for instance above the data device for
20 policy module. Several of these have been written as we experiment,
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
33 may be out of date or kept in sync with the copy on the cache device
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
62 (32KB) and 2097152 (1GB) and a multiple of 64 (32KB).
65 something of a compromise. For instance, a small part of a block may be
68 block sizes are bad because they increase the amount of metadata (both
92 the cache will gradually cool as writes take place. If the coherency of
93 the cache can later be verified, or established through use of the
102 blocks, in the area of the cache being removed, to be clean. If the
105 cache's fast device until the cache is clean. This is of particular
115 The user can set a throttle to prevent more than a certain amount of
117 account of normal io traffic going to the devices. More work needs
121 can be used to set the maximum number of sectors being migrated,
131 should always be consistent in spite of any crash.
141 Policy plug-ins can store a chunk of data per cache block. It's up to
147 uses this facility to store the hit count of the cache blocks. If
157 need a generic way of getting and setting these. Device-mapper
164 been discarded. A prime example of this is when mkfs discards the
165 whole block device. We store a bitset tracking the discard state of
168 state for all of the origin device (compare with the dirty bitset
186 #feature args : number of feature arguments passed
190 #policy args : an even number of arguments corresponding to
204 situations (e.g., rolling back snapshots of
214 the characteristics of a specific policy, always request it by name.
227 #used metadata blocks : Number of metadata blocks used
228 #total metadata blocks : Total number of metadata blocks
231 #used cache blocks : Number of blocks resident in the cache
232 #total cache blocks : Total number of cache blocks
233 #read hits : Number of times a READ bio has been mapped
235 #read misses : Number of times a READ bio has been mapped
237 #write hits : Number of times a WRITE bio has been mapped
239 #write misses : Number of times a WRITE bio has been
241 #demotions : Number of times a block has been removed
243 #promotions : Number of times a block has been moved to
245 #dirty : Number of blocks in the cache that differ
247 #feature args : Number of feature args to follow
249 #core args : Number of core arguments (must be even)
252 policy name : Name of the policy
253 #policy args : Number of policy arguments to follow (must be even)
261 need a generic way of getting and setting these. Device-mapper
274 message, which takes an arbitrary number of cblock ranges. Each cblock
276 of values from 5 to 9. Each cblock must be expressed as a decimal
279 invalidation of larger caches. The cache must be in passthrough mode