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| author | Arnd Bergmann <arnd@arndb.de> | 2009-06-12 09:53:47 +0200 |
|---|---|---|
| committer | Arnd Bergmann <arnd@arndb.de> | 2009-06-12 11:32:58 +0200 |
| commit | 5b02ee3d219f9e01b6e9146e25613822cfc2e5ce (patch) | |
| tree | 7ce9126738c3cf4b37d67170d0e4b34818c057a9 /Documentation/ABI/testing/sysfs-block | |
| parent | 26a28fa4fea5b8c65713aa50c124f76a88c7924d (diff) | |
| parent | 8ebf975608aaebd7feb33d77f07ba21a6380e086 (diff) | |
| download | talos-op-linux-5b02ee3d219f9e01b6e9146e25613822cfc2e5ce.tar.gz talos-op-linux-5b02ee3d219f9e01b6e9146e25613822cfc2e5ce.zip | |
asm-generic: merge branch 'master' of torvalds/linux-2.6
Fixes a merge conflict against the x86 tree caused by a fix to
atomic.h which I renamed to atomic_long.h.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Diffstat (limited to 'Documentation/ABI/testing/sysfs-block')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-block | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-block b/Documentation/ABI/testing/sysfs-block index 44f52a4f5903..cbbd3e069945 100644 --- a/Documentation/ABI/testing/sysfs-block +++ b/Documentation/ABI/testing/sysfs-block @@ -60,3 +60,62 @@ 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 the storage device can write + without resorting to read-modify-write operation. 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. + +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 preferred minimum I/O size, + which is the smallest request the device can perform + without incurring a read-modify-write penalty. For disk + drives this is often the physical block size. For RAID + arrays it is often the stripe chunk size. + +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 of receiving I/O. This is + rarely reported for disk drives. For RAID devices it is + usually the stripe width or the internal block size. |
