Параметры ядра Linux:Block layer

Материал из Wiki Open Book.

[править] Block layer --->

Enable the block layer

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.

This option will also disable SCSI character devices and USB storage 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.

Support for Large Block Devices

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.

Поддержка больших блочных устройств.

Нажмите Y, если хотите подключать диски объёмом более 2 Тбайт. Также данную опцию необходимо включить для поддержки raid или loopback устройств объёмом более 2 Тбайт.

В противном случае введите N.

	Support for tracing block io 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: `git://brick.kernel.dk/data/git/blktrace.git`

	Support for Large Single Files
	Say Y here if you want to be able to handle very large files (bigger than 2TB), otherwise say N. If unsure, say Y.

[править] IO Schedulers --->

Anticipatory I/O

The anticipatory I/O scheduler is the default disk scheduler. It is generally a good choice for most environments, but is quite large and complex when compared to the deadline I/O scheduler, it can also be slower in some cases especially some database loads.

Deadline I/O scheduler

The deadline I/O scheduler is simple and compact, and is often as good as the anticipatory I/O scheduler, and in some database workloads, better. In the case of a single process performing I/O to a disk at any one time, its behaviour is almost identical to the anticipatory I/O scheduler and so is a good choice.

CFQ I/O scheduler

The CFQ I/O scheduler tries to distribute bandwidth equally among all processes in the system. It should provide a fair working environment, suitable for desktop systems.