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Diffstat (limited to 'Documentation/ABI/testing/sysfs-block')
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diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block deleted file mode 100644 index 279da08f7541..000000000000 --- a/Documentation/ABI/testing/sysfs-block +++ /dev/null @@ -1,222 +0,0 @@ -What: /sys/block/<disk>/stat -Date: February 2008 -Contact: Jerome Marchand <jmarchan@redhat.com> -Description: - The /sys/block/<disk>/stat files displays the I/O - statistics of disk <disk>. They contain 11 fields: - 1 - reads completed successfully - 2 - reads merged - 3 - sectors read - 4 - time spent reading (ms) - 5 - writes completed - 6 - writes merged - 7 - sectors written - 8 - time spent writing (ms) - 9 - I/Os currently in progress - 10 - time spent doing I/Os (ms) - 11 - weighted time spent doing I/Os (ms) - For more details refer Documentation/iostats.txt - - -What: /sys/block/<disk>/<part>/stat -Date: February 2008 -Contact: Jerome Marchand <jmarchan@redhat.com> -Description: - The /sys/block/<disk>/<part>/stat files display the - I/O statistics of partition <part>. The format is the - same as the above-written /sys/block/<disk>/stat - format. - - -What: /sys/block/<disk>/integrity/format -Date: June 2008 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Metadata format for integrity capable block device. - E.g. T10-DIF-TYPE1-CRC. - - -What: /sys/block/<disk>/integrity/read_verify -Date: June 2008 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Indicates whether the block layer should verify the - integrity of read requests serviced by devices that - support sending integrity metadata. - - -What: /sys/block/<disk>/integrity/tag_size -Date: June 2008 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Number of bytes of integrity tag space available per - 512 bytes of data. - - -What: /sys/block/<disk>/integrity/write_generate -Date: June 2008 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Indicates whether the block layer should automatically - generate checksums for write requests bound for - devices that support receiving integrity metadata. - -What: /sys/block/<disk>/alignment_offset -Date: April 2009 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Storage devices may report a physical block size that is - bigger than the logical block size (for instance a drive - with 4KB physical sectors exposing 512-byte logical - blocks to the operating system). This parameter - indicates how many bytes the beginning of the device is - offset from the disk's natural alignment. - -What: /sys/block/<disk>/<partition>/alignment_offset -Date: April 2009 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Storage devices may report a physical block size that is - bigger than the logical block size (for instance a drive - with 4KB physical sectors exposing 512-byte logical - blocks to the operating system). This parameter - indicates how many bytes the beginning of the partition - is offset from the disk's natural alignment. - -What: /sys/block/<disk>/queue/logical_block_size -Date: May 2009 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - This is the smallest unit the storage device can - address. It is typically 512 bytes. - -What: /sys/block/<disk>/queue/physical_block_size -Date: May 2009 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - This is the smallest unit a physical storage device can - write atomically. It is usually the same as the logical - block size but may be bigger. One example is SATA - drives with 4KB sectors that expose a 512-byte logical - block size to the operating system. For stacked block - devices the physical_block_size variable contains the - maximum physical_block_size of the component devices. - -What: /sys/block/<disk>/queue/minimum_io_size -Date: April 2009 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Storage devices may report a granularity or preferred - minimum I/O size which is the smallest request the - device can perform without incurring a performance - penalty. For disk drives this is often the physical - block size. For RAID arrays it is often the stripe - chunk size. A properly aligned multiple of - minimum_io_size is the preferred request size for - workloads where a high number of I/O operations is - desired. - -What: /sys/block/<disk>/queue/optimal_io_size -Date: April 2009 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Storage devices may report an optimal I/O size, which is - the device's preferred unit for sustained I/O. This is - rarely reported for disk drives. For RAID arrays it is - usually the stripe width or the internal track size. A - properly aligned multiple of optimal_io_size is the - preferred request size for workloads where sustained - throughput is desired. If no optimal I/O size is - reported this file contains 0. - -What: /sys/block/<disk>/queue/nomerges -Date: January 2010 -Contact: -Description: - Standard I/O elevator operations include attempts to - merge contiguous I/Os. For known random I/O loads these - attempts will always fail and result in extra cycles - being spent in the kernel. This allows one to turn off - this behavior on one of two ways: When set to 1, complex - merge checks are disabled, but the simple one-shot merges - with the previous I/O request are enabled. When set to 2, - all merge tries are disabled. The default value is 0 - - which enables all types of merge tries. - -What: /sys/block/<disk>/discard_alignment -Date: May 2011 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Devices that support discard functionality may - internally allocate space in units that are bigger than - the exported logical block size. The discard_alignment - parameter indicates how many bytes the beginning of the - device is offset from the internal allocation unit's - natural alignment. - -What: /sys/block/<disk>/<partition>/discard_alignment -Date: May 2011 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Devices that support discard functionality may - internally allocate space in units that are bigger than - the exported logical block size. The discard_alignment - parameter indicates how many bytes the beginning of the - partition is offset from the internal allocation unit's - natural alignment. - -What: /sys/block/<disk>/queue/discard_granularity -Date: May 2011 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Devices that support discard functionality may - internally allocate space using units that are bigger - than the logical block size. The discard_granularity - parameter indicates the size of the internal allocation - unit in bytes if reported by the device. Otherwise the - discard_granularity will be set to match the device's - physical block size. A discard_granularity of 0 means - that the device does not support discard functionality. - -What: /sys/block/<disk>/queue/discard_max_bytes -Date: May 2011 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Devices that support discard functionality may have - internal limits on the number of bytes that can be - trimmed or unmapped in a single operation. Some storage - protocols also have inherent limits on the number of - blocks that can be described in a single command. The - discard_max_bytes parameter is set by the device driver - to the maximum number of bytes that can be discarded in - a single operation. Discard requests issued to the - device must not exceed this limit. A discard_max_bytes - value of 0 means that the device does not support - discard functionality. - -What: /sys/block/<disk>/queue/discard_zeroes_data -Date: May 2011 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Devices that support discard functionality may return - stale or random data when a previously discarded block - is read back. This can cause problems if the filesystem - expects discarded blocks to be explicitly cleared. If a - device reports that it deterministically returns zeroes - when a discarded area is read the discard_zeroes_data - parameter will be set to one. Otherwise it will be 0 and - the result of reading a discarded area is undefined. - -What: /sys/block/<disk>/queue/write_same_max_bytes -Date: January 2012 -Contact: Martin K. Petersen <martin.petersen@oracle.com> -Description: - Some devices support a write same operation in which a - single data block can be written to a range of several - contiguous blocks on storage. This can be used to wipe - areas on disk or to initialize drives in a RAID - configuration. write_same_max_bytes indicates how many - bytes can be written in a single write same command. If - write_same_max_bytes is 0, write same is not supported - by the device. - |