tree-wide: fix assorted typos all over the place

[safe/jmp/linux-2.6] / Documentation / ABI / testing / sysfs-block

diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block
index 44f52a4..d2f9033 100644 (file)
--- a/Documentation/ABI/testing/sysfs-block
+++ b/Documentation/ABI/testing/sysfs-block
@@ -4,7 +4,7 @@ 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 succesfully
+                1 - reads completed successfully
                 2 - reads merged
                 3 - sectors read
                 4 - time spent reading (ms)
@@ -60,3 +60,71 @@ 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.