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It doesn't cache reads because reads are supposed to be cached in page cache in normal RAM.”h]”hŒ¡The writecache target caches writes on persistent memory or on SSD. It doesn’t cache reads because reads are supposed to be cached in page cache in normal RAM.”…””}”(hhÍh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khh·h²hubhÌ)”}”(hŒWhen the device is constructed, the first sector should be zeroed or the first sector should contain valid superblock from previous invocation.”h]”hŒWhen the device is constructed, the first sector should be zeroed or the first sector should contain valid superblock from previous invocation.”…””}”(hhÛh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K hh·h²hubhÌ)”}”(hŒConstructor parameters:”h]”hŒConstructor parameters:”…””}”(hhéh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K hh·h²hubhŒenumerated_list”“”)”}”(hhh]”(hŒ list_item”“”)”}”(hŒQtype of the cache device - "p" or "s" - p - persistent memory - s - SSD”h]”hŒdefinition_list”“”)”}”(hhh]”hŒdefinition_list_item”“”)”}”(hŒGtype of the cache device - "p" or "s" - p - persistent memory - s - SSD”h]”(hŒterm”“”)”}”(hŒ%type of the cache device - "p" or "s"”h]”hŒ-type of the cache device - “p†or “s—…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´Khj ubhŒ definition”“”)”}”(hhh]”hŒ bullet_list”“”)”}”(hhh]”(hý)”}”(hŒp - persistent memory”h]”hÌ)”}”(hj)h]”hŒp - persistent memory”…””}”(hj+h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khj'ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühj$ubhý)”}”(hŒs - SSD”h]”hÌ)”}”(hj@h]”hŒs - SSD”…””}”(hjBh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khj>ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühj$ubeh}”(h]”h ]”h"]”h$]”h&]”Œbullet”Œ-”uh1j"h³hÊh´Khjubah}”(h]”h ]”h"]”h$]”h&]”uh1jhj ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´Khjubah}”(h]”h ]”h"]”h$]”h&]”uh1jhhþubah}”(h]”h ]”h"]”h$]”h&]”uh1hühhùh²hh³Nh´Nubhý)”}”(hŒ)the underlying device that will be cached”h]”hÌ)”}”(hjwh]”hŒ)the underlying device that will be cached”…””}”(hjyh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khjuubah}”(h]”h ]”h"]”h$]”h&]”uh1hühhùh²hh³hÊh´Nubhý)”}”(hŒthe cache device”h]”hÌ)”}”(hjŽh]”hŒthe cache device”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KhjŒubah}”(h]”h ]”h"]”h$]”h&]”uh1hühhùh²hh³hÊh´Nubhý)”}”(hŒIblock size (4096 is recommended; the maximum block size is the page size)”h]”hÌ)”}”(hŒIblock size (4096 is recommended; the maximum block size is the page size)”h]”hŒIblock size (4096 is recommended; the maximum block size is the page size)”…””}”(hj§h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khj£ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühhùh²hh³hÊh´Nubhý)”}”(hX the number of optional parameters (the parameters with an argument count as two) start_sector n (default: 0) offset from the start of cache device in 512-byte sectors high_watermark n (default: 50) start writeback when the number of used blocks reach this watermark low_watermark x (default: 45) stop writeback when the number of used blocks drops below this watermark writeback_jobs n (default: unlimited) limit the number of blocks that are in flight during writeback. Setting this value reduces writeback throughput, but it may improve latency of read requests autocommit_blocks n (default: 64 for pmem, 65536 for ssd) when the application writes this amount of blocks without issuing the FLUSH request, the blocks are automatically committed autocommit_time ms (default: 1000) autocommit time in milliseconds. The data is automatically committed if this time passes and no FLUSH request is received fua (by default on) applicable only to persistent memory - use the FUA flag when writing data from persistent memory back to the underlying device nofua applicable only to persistent memory - don't use the FUA flag when writing back data and send the FLUSH request afterwards - some underlying devices perform better with fua, some with nofua. The user should test it cleaner when this option is activated (either in the constructor arguments or by a message), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached blocks drops to zero, userspace can unload the dm-writecache target and replace it with dm-linear or other targets. max_age n specifies the maximum age of a block in milliseconds. If a block is stored in the cache for too long, it will be written to the underlying device and cleaned up. metadata_only only metadata is promoted to the cache. This option improves performance for heavier REQ_META workloads. pause_writeback n (default: 3000) pause writeback if there was some write I/O redirected to the origin volume in the last n milliseconds ”h]”(hÌ)”}”(hŒPthe number of optional parameters (the parameters with an argument count as two)”h]”hŒPthe number of optional parameters (the parameters with an argument count as two)”…””}”(hj¿h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khj»ubhŒ block_quote”“”)”}”(hXÇ start_sector n (default: 0) offset from the start of cache device in 512-byte sectors high_watermark n (default: 50) start writeback when the number of used blocks reach this watermark low_watermark x (default: 45) stop writeback when the number of used blocks drops below this watermark writeback_jobs n (default: unlimited) limit the number of blocks that are in flight during writeback. Setting this value reduces writeback throughput, but it may improve latency of read requests autocommit_blocks n (default: 64 for pmem, 65536 for ssd) when the application writes this amount of blocks without issuing the FLUSH request, the blocks are automatically committed autocommit_time ms (default: 1000) autocommit time in milliseconds. The data is automatically committed if this time passes and no FLUSH request is received fua (by default on) applicable only to persistent memory - use the FUA flag when writing data from persistent memory back to the underlying device nofua applicable only to persistent memory - don't use the FUA flag when writing back data and send the FLUSH request afterwards - some underlying devices perform better with fua, some with nofua. The user should test it cleaner when this option is activated (either in the constructor arguments or by a message), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached blocks drops to zero, userspace can unload the dm-writecache target and replace it with dm-linear or other targets. max_age n specifies the maximum age of a block in milliseconds. If a block is stored in the cache for too long, it will be written to the underlying device and cleaned up. metadata_only only metadata is promoted to the cache. This option improves performance for heavier REQ_META workloads. pause_writeback n (default: 3000) pause writeback if there was some write I/O redirected to the origin volume in the last n milliseconds ”h]”j)”}”(hhh]”(j)”}”(hŒ^start_sector n (default: 0) offset from the start of cache device in 512-byte sectors”h]”(j)”}”(hŒ$start_sector n (default: 0)”h]”hŒ$start_sector n (default: 0)”…””}”(hjÚh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´KhjÖubj)”}”(hhh]”hÌ)”}”(hŒ9offset from the start of cache device in 512-byte sectors”h]”hŒ9offset from the start of cache device in 512-byte sectors”…””}”(hjëh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khjèubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjÖubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´KhjÓubj)”}”(hŒihigh_watermark n (default: 50) start writeback when the number of used blocks reach this watermark”h]”(j)”}”(hŒ%high_watermark n (default: 50)”h]”hŒ%high_watermark n (default: 50)”…””}”(hj h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´Khjubj)”}”(hhh]”hÌ)”}”(hŒCstart writeback when the number of used blocks reach this watermark”h]”hŒCstart writeback when the number of used blocks reach this watermark”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khjubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´KhjÓubj)”}”(hŒnlow_watermark x (default: 45) stop writeback when the number of used blocks drops below this watermark”h]”(j)”}”(hŒ%low_watermark x (default: 45)”h]”hŒ%low_watermark x (default: 45)”…””}”(hj8h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´Khj4ubj)”}”(hhh]”hÌ)”}”(hŒHstop writeback when the number of used blocks drops below this watermark”h]”hŒHstop writeback when the number of used blocks drops below this watermark”…””}”(hjIh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KhjFubah}”(h]”h ]”h"]”h$]”h&]”uh1jhj4ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´KhjÓubj)”}”(hŒÉwriteback_jobs n (default: unlimited) limit the number of blocks that are in flight during writeback. Setting this value reduces writeback throughput, but it may improve latency of read requests”h]”(j)”}”(hŒ,writeback_jobs n (default: unlimited)”h]”hŒ,writeback_jobs n (default: unlimited)”…””}”(hjgh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´K"hjcubj)”}”(hhh]”hÌ)”}”(hŒœlimit the number of blocks that are in flight during writeback. Setting this value reduces writeback throughput, but it may improve latency of read requests”h]”hŒœlimit the number of blocks that are in flight during writeback. Setting this value reduces writeback throughput, but it may improve latency of read requests”…””}”(hjxh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K!hjuubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjcubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´K"hjÓubj)”}”(hŒ¹autocommit_blocks n (default: 64 for pmem, 65536 for ssd) when the application writes this amount of blocks without issuing the FLUSH request, the blocks are automatically committed”h]”(j)”}”(hŒ=autocommit_blocks n (default: 64 for pmem, 65536 for ssd)”h]”hŒ=autocommit_blocks n (default: 64 for pmem, 65536 for ssd)”…””}”(hj–h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´K&hj’ubj)”}”(hhh]”hÌ)”}”(hŒ{when the application writes this amount of blocks without issuing the FLUSH request, the blocks are automatically committed”h]”hŒ{when the application writes this amount of blocks without issuing the FLUSH request, the blocks are automatically committed”…””}”(hj§h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K%hj¤ubah}”(h]”h ]”h"]”h$]”h&]”uh1jhj’ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´K&hjÓubj)”}”(hŒ¡autocommit_time ms (default: 1000) autocommit time in milliseconds. The data is automatically committed if this time passes and no FLUSH request is received”h]”(j)”}”(hŒ'autocommit_time ms (default: 1000)”h]”hŒ'autocommit_time ms (default: 1000)”…””}”(hjÅh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´K*hjÁubj)”}”(hhh]”hÌ)”}”(hŒyautocommit time in milliseconds. The data is automatically committed if this time passes and no FLUSH request is received”h]”hŒyautocommit time in milliseconds. The data is automatically committed if this time passes and no FLUSH request is received”…””}”(hjÖh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K)hjÓubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjÁubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´K*hjÓubj)”}”(hŒ¦fua (by default on) applicable only to persistent memory - use the FUA flag when writing data from persistent memory back to the underlying device”h]”(j)”}”(hŒ'fua (by default on)”h]”hŒ'fua (by default on)”…””}”(hjôh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´K.hjðubj)”}”(hhh]”hÌ)”}”(hŒ~applicable only to persistent memory - use the FUA flag when writing data from persistent memory back to the underlying device”h]”hŒ~applicable only to persistent memory - use the FUA flag when writing data from persistent memory back to the underlying device”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K-hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjðubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´K.hjÓubj)”}”(hŒßnofua applicable only to persistent memory - don't use the FUA flag when writing back data and send the FLUSH request afterwards - some underlying devices perform better with fua, some with nofua. The user should test it”h]”(j)”}”(hŒnofua”h]”hŒnofua”…””}”(hj#h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´K5hjubj)”}”(hhh]”(hÌ)”}”(hŒzapplicable only to persistent memory - don't use the FUA flag when writing back data and send the FLUSH request afterwards”h]”hŒ|applicable only to persistent memory - don’t use the FUA flag when writing back data and send the FLUSH request afterwards”…””}”(hj4h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K1hj1ubj#)”}”(hhh]”hý)”}”(hŒYsome underlying devices perform better with fua, some with nofua. The user should test it”h]”hÌ)”}”(hŒYsome underlying devices perform better with fua, some with nofua. The user should test it”h]”hŒYsome underlying devices perform better with fua, some with nofua. The user should test it”…””}”(hjIh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K5hjEubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjBubah}”(h]”h ]”h"]”h$]”h&]”j[j\uh1j"h³hÊh´K5hj1ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jhjubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´K5hjÓubj)”}”(hX÷cleaner when this option is activated (either in the constructor arguments or by a message), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached blocks drops to zero, userspace can unload the dm-writecache target and replace it with dm-linear or other targets.”h]”(j)”}”(hŒcleaner”h]”hŒcleaner”…””}”(hjsh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´K@hjoubj)”}”(hhh]”hÌ)”}”(hXïwhen this option is activated (either in the constructor arguments or by a message), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with "dmsetup status". When the number of cached blocks drops to zero, userspace can unload the dm-writecache target and replace it with dm-linear or other targets.”h]”hXówhen this option is activated (either in the constructor arguments or by a message), the cache will not promote new writes (however, writes to already cached blocks are promoted, to avoid data corruption due to misordered writes) and it will gradually writeback any cached data. The userspace can then monitor the cleaning process with “dmsetup statusâ€. When the number of cached blocks drops to zero, userspace can unload the dm-writecache target and replace it with dm-linear or other targets.”…””}”(hj„h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K8hjubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjoubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´K@hjÓubj)”}”(hŒ«max_age n specifies the maximum age of a block in milliseconds. If a block is stored in the cache for too long, it will be written to the underlying device and cleaned up.”h]”(j)”}”(hŒ max_age n”h]”hŒ max_age n”…””}”(hj¢h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´KDhjžubj)”}”(hhh]”hÌ)”}”(hŒ¡specifies the maximum age of a block in milliseconds. If a block is stored in the cache for too long, it will be written to the underlying device and cleaned up.”h]”hŒ¡specifies the maximum age of a block in milliseconds. If a block is stored in the cache for too long, it will be written to the underlying device and cleaned up.”…””}”(hj³h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KChj°ubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjžubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´KDhjÓubj)”}”(hŒvmetadata_only only metadata is promoted to the cache. This option improves performance for heavier REQ_META workloads.”h]”(j)”}”(hŒ metadata_only”h]”hŒ metadata_only”…””}”(hjÑh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´KGhjÍubj)”}”(hhh]”hÌ)”}”(hŒhonly metadata is promoted to the cache. This option improves performance for heavier REQ_META workloads.”h]”hŒhonly metadata is promoted to the cache. This option improves performance for heavier REQ_META workloads.”…””}”(hjâh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KGhjßubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjÍubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´KGhjÓubj)”}”(hŒpause_writeback n (default: 3000) pause writeback if there was some write I/O redirected to the origin volume in the last n milliseconds ”h]”(j)”}”(hŒ'pause_writeback n (default: 3000)”h]”hŒ'pause_writeback n (default: 3000)”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´KKhjüubj)”}”(hhh]”hÌ)”}”(hŒfpause writeback if there was some write I/O redirected to the origin volume in the last n milliseconds”h]”hŒfpause writeback if there was some write I/O redirected to the origin volume in the last n milliseconds”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KJhjubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjüubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´KKhjÓubeh}”(h]”h ]”h"]”h$]”h&]”uh1jhjÏubah}”(h]”h ]”h"]”h$]”h&]”uh1jÍh³hÊh´Khj»ubeh}”(h]”h ]”h"]”h$]”h&]”uh1hühhùh²hh³hÊh´Nubeh}”(h]”h ]”h"]”h$]”h&]”Œenumtype”Œarabic”Œprefix”hŒsuffix”Œ.”uh1h÷hh·h²hh³hÊh´KubhÌ)”}”(hŒStatus:”h]”hŒStatus:”…””}”(hjHh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KMhh·h²hubhø)”}”(hhh]”(hý)”}”(hŒAerror indicator - 0 if there was no error, otherwise error number”h]”hÌ)”}”(hj[h]”hŒAerror indicator - 0 if there was no error, otherwise error number”…””}”(hj]h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KOhjYubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒthe number of blocks”h]”hÌ)”}”(hjrh]”hŒthe number of blocks”…””}”(hjth²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KPhjpubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒthe number of free blocks”h]”hÌ)”}”(hj‰h]”hŒthe number of free blocks”…””}”(hj‹h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KQhj‡ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒ$the number of blocks under writeback”h]”hÌ)”}”(hj h]”hŒ$the number of blocks under writeback”…””}”(hj¢h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KRhjžubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒthe number of read blocks”h]”hÌ)”}”(hj·h]”hŒthe number of read blocks”…””}”(hj¹h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KShjµubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒ,the number of read blocks that hit the cache”h]”hÌ)”}”(hjÎh]”hŒ,the number of read blocks that hit the cache”…””}”(hjÐh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KThjÌubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒthe number of write blocks”h]”hÌ)”}”(hjåh]”hŒthe number of write blocks”…””}”(hjçh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KUhjãubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒ5the number of write blocks that hit uncommitted block”h]”hÌ)”}”(hjüh]”hŒ5the number of write blocks that hit uncommitted block”…””}”(hjþh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KVhjúubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒ3the number of write blocks that hit committed block”h]”hÌ)”}”(hjh]”hŒ3the number of write blocks that hit committed block”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KWhjubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒ0the number of write blocks that bypass the cache”h]”hÌ)”}”(hj*h]”hŒ0the number of write blocks that bypass the cache”…””}”(hj,h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KXhj(ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒ:the number of write blocks that are allocated in the cache”h]”hÌ)”}”(hjAh]”hŒ:the number of write blocks that are allocated in the cache”…””}”(hjCh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KYhj?ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒ=the number of write requests that are blocked on the freelist”h]”hÌ)”}”(hjXh]”hŒ=the number of write requests that are blocked on the freelist”…””}”(hjZh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KZhjVubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒthe number of flush requests”h]”hÌ)”}”(hjoh]”hŒthe number of flush requests”…””}”(hjqh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K[hjmubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubhý)”}”(hŒthe number of discarded blocks ”h]”hÌ)”}”(hŒthe number of discarded blocks”h]”hŒthe number of discarded blocks”…””}”(hjˆh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K\hj„ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjVh²hh³hÊh´Nubeh}”(h]”h ]”h"]”h$]”h&]”jCjDjEhjFjGuh1h÷hh·h²hh³hÊh´KOubj)”}”(hhh]”j)”}”(hX_Messages: flush Flush the cache device. The message returns successfully if the cache device was flushed without an error flush_on_suspend Flush the cache device on next suspend. Use this message when you are going to remove the cache device. The proper sequence for removing the cache device is: 1. send the "flush_on_suspend" message 2. load an inactive table with a linear target that maps to the underlying device 3. suspend the device 4. ask for status and verify that there are no errors 5. resume the device, so that it will use the linear target 6. the cache device is now inactive and it can be deleted cleaner See above "cleaner" constructor documentation. clear_stats Clear the statistics that are reported on the status line”h]”(j)”}”(hŒ Messages:”h]”hŒ Messages:”…””}”(hj©h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´Kqhj¥ubj)”}”(hhh]”j)”}”(hhh]”(j)”}”(hŒoflush Flush the cache device. The message returns successfully if the cache device was flushed without an error”h]”(j)”}”(hŒflush”h]”hŒflush”…””}”(hjÁh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´K`hj½ubj)”}”(hhh]”hÌ)”}”(hŒiFlush the cache device. The message returns successfully if the cache device was flushed without an error”h]”hŒiFlush the cache device. The message returns successfully if the cache device was flushed without an error”…””}”(hjÒh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´K`hjÏubah}”(h]”h ]”h"]”h$]”h&]”uh1jhj½ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´K`hjºubj)”}”(hXðflush_on_suspend Flush the cache device on next suspend. Use this message when you are going to remove the cache device. The proper sequence for removing the cache device is: 1. send the "flush_on_suspend" message 2. load an inactive table with a linear target that maps to the underlying device 3. suspend the device 4. ask for status and verify that there are no errors 5. resume the device, so that it will use the linear target 6. the cache device is now inactive and it can be deleted”h]”(j)”}”(hŒflush_on_suspend”h]”hŒflush_on_suspend”…””}”(hjðh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´Kmhjìubj)”}”(hhh]”(hÌ)”}”(hŒFlush the cache device on next suspend. Use this message when you are going to remove the cache device. The proper sequence for removing the cache device is:”h]”hŒFlush the cache device on next suspend. Use this message when you are going to remove the cache device. The proper sequence for removing the cache device is:”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kchjþubhø)”}”(hhh]”(hý)”}”(hŒ#send the "flush_on_suspend" message”h]”hÌ)”}”(hjh]”hŒ'send the “flush_on_suspend†message”…””}”(hjh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Kghjubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjubhý)”}”(hŒNload an inactive table with a linear target that maps to the underlying device”h]”hÌ)”}”(hŒNload an inactive table with a linear target that maps to the underlying device”h]”hŒNload an inactive table with a linear target that maps to the underlying device”…””}”(hj-h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Khhj)ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjubhý)”}”(hŒsuspend the device”h]”hÌ)”}”(hjCh]”hŒsuspend the device”…””}”(hjEh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KjhjAubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjubhý)”}”(hŒ2ask for status and verify that there are no errors”h]”hÌ)”}”(hjZh]”hŒ2ask for status and verify that there are no errors”…””}”(hj\h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KkhjXubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjubhý)”}”(hŒ8resume the device, so that it will use the linear target”h]”hÌ)”}”(hŒ8resume the device, so that it will use the linear target”h]”hŒ8resume the device, so that it will use the linear target”…””}”(hjsh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Klhjoubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjubhý)”}”(hŒ6the cache device is now inactive and it can be deleted”h]”hÌ)”}”(hj‰h]”hŒ6the cache device is now inactive and it can be deleted”…””}”(hj‹h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Knhj‡ubah}”(h]”h ]”h"]”h$]”h&]”uh1hühjubeh}”(h]”h ]”h"]”h$]”h&]”jCjDjEhjFjGuh1h÷hjþubeh}”(h]”h ]”h"]”h$]”h&]”uh1jhjìubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´Kmhjºubj)”}”(hŒ6cleaner See above "cleaner" constructor documentation.”h]”(j)”}”(hŒcleaner”h]”hŒcleaner”…””}”(hj´h²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´Kohj°ubj)”}”(hhh]”hÌ)”}”(hŒ.See above "cleaner" constructor documentation.”h]”hŒ2See above “cleaner†constructor documentation.”…””}”(hjÅh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´KphjÂubah}”(h]”h ]”h"]”h$]”h&]”uh1jhj°ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´Kohjºubj)”}”(hŒEclear_stats Clear the statistics that are reported on the status line”h]”(j)”}”(hŒ clear_stats”h]”hŒ clear_stats”…””}”(hjãh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1j h³hÊh´Kqhjßubj)”}”(hhh]”hÌ)”}”(hŒ9Clear the statistics that are reported on the status line”h]”hŒ9Clear the statistics that are reported on the status line”…””}”(hjôh²hh³Nh´Nubah}”(h]”h ]”h"]”h$]”h&]”uh1hËh³hÊh´Krhjñubah}”(h]”h ]”h"]”h$]”h&]”uh1jhjßubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´Kqhjºubeh}”(h]”h ]”h"]”h$]”h&]”uh1jhj·ubah}”(h]”h ]”h"]”h$]”h&]”uh1jhj¥ubeh}”(h]”h ]”h"]”h$]”h&]”uh1jh³hÊh´Kqhj¢ubah}”(h]”h ]”h"]”h$]”h&]”uh1jhh·h²hh³Nh´Nubeh}”(h]”Œwritecache-target”ah ]”h"]”Œwritecache target”ah$]”h&]”uh1hµhhh²hh³hÊh´Kubeh}”(h]”h ]”h"]”h$]”h&]”Œsource”hÊuh1hŒcurrent_source”NŒ current_line”NŒsettings”Œdocutils.frontend”ŒValues”“”)”}”(hºNŒ generator”NŒ datestamp”NŒ source_link”NŒ source_url”NŒ toc_backlinks”Œentry”Œfootnote_backlinks”KŒ sectnum_xform”KŒstrip_comments”NŒstrip_elements_with_classes”NŒ strip_classes”NŒ report_level”KŒ halt_level”KŒexit_status_level”KŒdebug”NŒwarning_stream”NŒ traceback”ˆŒinput_encoding”Œ utf-8-sig”Œinput_encoding_error_handler”Œstrict”Œoutput_encoding”Œutf-8”Œoutput_encoding_error_handler”jQŒerror_encoding”Œutf-8”Œerror_encoding_error_handler”Œbackslashreplace”Œ language_code”Œen”Œrecord_dependencies”NŒconfig”NŒ id_prefix”hŒauto_id_prefix”Œid”Œ dump_settings”NŒdump_internals”NŒdump_transforms”NŒdump_pseudo_xml”NŒexpose_internals”NŒstrict_visitor”NŒ_disable_config”NŒ_source”hÊŒ _destination”NŒ _config_files”]”Œ7/var/lib/git/docbuild/linux/Documentation/docutils.conf”aŒfile_insertion_enabled”ˆŒ raw_enabled”KŒline_length_limit”M'Œpep_references”NŒ pep_base_url”Œhttps://peps.python.org/”Œpep_file_url_template”Œpep-%04d”Œrfc_references”NŒ rfc_base_url”Œ&https://datatracker.ietf.org/doc/html/”Œ tab_width”KŒtrim_footnote_reference_space”‰Œsyntax_highlight”Œlong”Œ smart_quotes”ˆŒsmartquotes_locales”]”Œcharacter_level_inline_markup”‰Œdoctitle_xform”‰Œ docinfo_xform”KŒsectsubtitle_xform”‰Œ image_loading”Œlink”Œembed_stylesheet”‰Œcloak_email_addresses”ˆŒsection_self_link”‰Œenv”NubŒreporter”NŒindirect_targets”]”Œsubstitution_defs”}”Œsubstitution_names”}”Œrefnames”}”Œrefids”}”Œnameids”}”j+j(sŒ nametypes”}”j+‰sh}”j(h·sŒ footnote_refs”}”Œ citation_refs”}”Œ autofootnotes”]”Œautofootnote_refs”]”Œsymbol_footnotes”]”Œsymbol_footnote_refs”]”Œ footnotes”]”Œ citations”]”Œautofootnote_start”KŒsymbol_footnote_start”KŒ id_counter”Œ collections”ŒCounter”“”}”…”R”Œparse_messages”]”Œtransform_messages”]”Œ transformer”NŒ include_log”]”Œ decoration”Nh²hub.