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-rw-r--r--block/Kconfig65
1 files changed, 42 insertions, 23 deletions
diff --git a/block/Kconfig b/block/Kconfig
index 7db9a411649d..3e97f2bc446f 100644
--- a/block/Kconfig
+++ b/block/Kconfig
@@ -5,14 +5,18 @@ menuconfig BLOCK
bool "Enable the block layer" if EMBEDDED
default y
help
- This permits the block layer to be removed from the kernel if it's not
- needed (on some embedded devices for example). If this option is
- disabled, then blockdev files will become unusable and some
- filesystems (such as ext3) will become unavailable.
+ Provide block layer support for the kernel.
- This option will also disable SCSI character devices and USB storage
- since they make use of various block layer definitions and
- facilities.
+ Disable this option to remove the block layer support from the
+ kernel. This may be useful for embedded devices.
+
+ If this option is disabled:
+
+ - block device files will become unusable
+ - some filesystems (such as ext3) will become unavailable.
+
+ Also, SCSI character devices and USB storage will be disabled since
+ they make use of various block layer definitions and facilities.
Say Y here unless you know you really don't want to mount disks and
suchlike.
@@ -23,9 +27,20 @@ config LBD
bool "Support for Large Block Devices"
depends on !64BIT
help
- Say Y here if you want to attach large (bigger than 2TB) discs to
- your machine, or if you want to have a raid or loopback device
- bigger than 2TB. Otherwise say N.
+ Enable block devices of size 2TB and larger.
+
+ This option is required to support the full capacity of large
+ (2TB+) block devices, including RAID, disk, Network Block Device,
+ Logical Volume Manager (LVM) and loopback.
+
+ For example, RAID devices are frequently bigger than the capacity
+ of the largest individual hard drive.
+
+ This option is not required if you have individual disk drives
+ which total 2TB+ and you are not aggregating the capacity into
+ a large block device (e.g. using RAID or LVM).
+
+ If unsure, say N.
config BLK_DEV_IO_TRACE
bool "Support for tracing block io actions"
@@ -33,19 +48,21 @@ config BLK_DEV_IO_TRACE
select RELAY
select DEBUG_FS
help
- Say Y here, if you want to be able to trace the block layer actions
+ Say Y here if you want to be able to trace the block layer actions
on a given queue. Tracing allows you to see any traffic happening
- on a block device queue. For more information (and the user space
- support tools needed), fetch the blktrace app from:
+ on a block device queue. For more information (and the userspace
+ support tools needed), fetch the blktrace tools from:
git://git.kernel.dk/blktrace.git
+ If unsure, say N.
+
config LSF
bool "Support for Large Single Files"
depends on !64BIT
help
- Say Y here if you want to be able to handle very large files (bigger
- than 2TB), otherwise say N.
+ Say Y here if you want to be able to handle very large files (2TB
+ and larger), otherwise say N.
If unsure, say Y.
@@ -53,14 +70,16 @@ config BLK_DEV_BSG
bool "Block layer SG support v4 (EXPERIMENTAL)"
depends on EXPERIMENTAL
---help---
- Saying Y here will enable generic SG (SCSI generic) v4 support
- for any block device.
-
- Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
- can handle complicated SCSI commands: tagged variable length cdbs
- with bidirectional data transfers and generic request/response
- protocols (e.g. Task Management Functions and SMP in Serial
- Attached SCSI).
+ Saying Y here will enable generic SG (SCSI generic) v4 support
+ for any block device.
+
+ Unlike SG v3 (aka block/scsi_ioctl.c drivers/scsi/sg.c), SG v4
+ can handle complicated SCSI commands: tagged variable length cdbs
+ with bidirectional data transfers and generic request/response
+ protocols (e.g. Task Management Functions and SMP in Serial
+ Attached SCSI).
+
+ If unsure, say N.
endif # BLOCK