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Diffstat (limited to 'drivers/md/Kconfig')
-rw-r--r-- | drivers/md/Kconfig | 292 |
1 files changed, 292 insertions, 0 deletions
diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig new file mode 100644 index 0000000..2281b50 --- /dev/null +++ b/drivers/md/Kconfig @@ -0,0 +1,292 @@ +# +# Block device driver configuration +# + +menuconfig MD + bool "Multiple devices driver support (RAID and LVM)" + depends on BLOCK + help + Support multiple physical spindles through a single logical device. + Required for RAID and logical volume management. + +if MD + +config BLK_DEV_MD + tristate "RAID support" + ---help--- + This driver lets you combine several hard disk partitions into one + logical block device. This can be used to simply append one + partition to another one or to combine several redundant hard disks + into a RAID1/4/5 device so as to provide protection against hard + disk failures. This is called "Software RAID" since the combining of + the partitions is done by the kernel. "Hardware RAID" means that the + combining is done by a dedicated controller; if you have such a + controller, you do not need to say Y here. + + More information about Software RAID on Linux is contained in the + Software RAID mini-HOWTO, available from + <http://www.tldp.org/docs.html#howto>. There you will also learn + where to get the supporting user space utilities raidtools. + + If unsure, say N. + +config MD_AUTODETECT + bool "Autodetect RAID arrays during kernel boot" + depends on BLK_DEV_MD=y + default y + ---help--- + If you say Y here, then the kernel will try to autodetect raid + arrays as part of its boot process. + + If you don't use raid and say Y, this autodetection can cause + a several-second delay in the boot time due to various + synchronisation steps that are part of this step. + + If unsure, say Y. + +config MD_LINEAR + tristate "Linear (append) mode" + depends on BLK_DEV_MD + ---help--- + If you say Y here, then your multiple devices driver will be able to + use the so-called linear mode, i.e. it will combine the hard disk + partitions by simply appending one to the other. + + To compile this as a module, choose M here: the module + will be called linear. + + If unsure, say Y. + +config MD_RAID0 + tristate "RAID-0 (striping) mode" + depends on BLK_DEV_MD + ---help--- + If you say Y here, then your multiple devices driver will be able to + use the so-called raid0 mode, i.e. it will combine the hard disk + partitions into one logical device in such a fashion as to fill them + up evenly, one chunk here and one chunk there. This will increase + the throughput rate if the partitions reside on distinct disks. + + Information about Software RAID on Linux is contained in the + Software-RAID mini-HOWTO, available from + <http://www.tldp.org/docs.html#howto>. There you will also + learn where to get the supporting user space utilities raidtools. + + To compile this as a module, choose M here: the module + will be called raid0. + + If unsure, say Y. + +config MD_RAID1 + tristate "RAID-1 (mirroring) mode" + depends on BLK_DEV_MD + ---help--- + A RAID-1 set consists of several disk drives which are exact copies + of each other. In the event of a mirror failure, the RAID driver + will continue to use the operational mirrors in the set, providing + an error free MD (multiple device) to the higher levels of the + kernel. In a set with N drives, the available space is the capacity + of a single drive, and the set protects against a failure of (N - 1) + drives. + + Information about Software RAID on Linux is contained in the + Software-RAID mini-HOWTO, available from + <http://www.tldp.org/docs.html#howto>. There you will also + learn where to get the supporting user space utilities raidtools. + + If you want to use such a RAID-1 set, say Y. To compile this code + as a module, choose M here: the module will be called raid1. + + If unsure, say Y. + +config MD_RAID10 + tristate "RAID-10 (mirrored striping) mode (EXPERIMENTAL)" + depends on BLK_DEV_MD && EXPERIMENTAL + ---help--- + RAID-10 provides a combination of striping (RAID-0) and + mirroring (RAID-1) with easier configuration and more flexible + layout. + Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to + be the same size (or at least, only as much as the smallest device + will be used). + RAID-10 provides a variety of layouts that provide different levels + of redundancy and performance. + + RAID-10 requires mdadm-1.7.0 or later, available at: + + ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/ + + If unsure, say Y. + +config MD_RAID456 + tristate "RAID-4/RAID-5/RAID-6 mode" + depends on BLK_DEV_MD + select ASYNC_MEMCPY + select ASYNC_XOR + ---help--- + A RAID-5 set of N drives with a capacity of C MB per drive provides + the capacity of C * (N - 1) MB, and protects against a failure + of a single drive. For a given sector (row) number, (N - 1) drives + contain data sectors, and one drive contains the parity protection. + For a RAID-4 set, the parity blocks are present on a single drive, + while a RAID-5 set distributes the parity across the drives in one + of the available parity distribution methods. + + A RAID-6 set of N drives with a capacity of C MB per drive + provides the capacity of C * (N - 2) MB, and protects + against a failure of any two drives. For a given sector + (row) number, (N - 2) drives contain data sectors, and two + drives contains two independent redundancy syndromes. Like + RAID-5, RAID-6 distributes the syndromes across the drives + in one of the available parity distribution methods. + + Information about Software RAID on Linux is contained in the + Software-RAID mini-HOWTO, available from + <http://www.tldp.org/docs.html#howto>. There you will also + learn where to get the supporting user space utilities raidtools. + + If you want to use such a RAID-4/RAID-5/RAID-6 set, say Y. To + compile this code as a module, choose M here: the module + will be called raid456. + + If unsure, say Y. + +config MD_RAID5_RESHAPE + bool "Support adding drives to a raid-5 array" + depends on MD_RAID456 + default y + ---help--- + A RAID-5 set can be expanded by adding extra drives. This + requires "restriping" the array which means (almost) every + block must be written to a different place. + + This option allows such restriping to be done while the array + is online. + + You will need mdadm version 2.4.1 or later to use this + feature safely. During the early stage of reshape there is + a critical section where live data is being over-written. A + crash during this time needs extra care for recovery. The + newer mdadm takes a copy of the data in the critical section + and will restore it, if necessary, after a crash. + + The mdadm usage is e.g. + mdadm --grow /dev/md1 --raid-disks=6 + to grow '/dev/md1' to having 6 disks. + + Note: The array can only be expanded, not contracted. + There should be enough spares already present to make the new + array workable. + + If unsure, say Y. + +config MD_MULTIPATH + tristate "Multipath I/O support" + depends on BLK_DEV_MD + help + Multipath-IO is the ability of certain devices to address the same + physical disk over multiple 'IO paths'. The code ensures that such + paths can be defined and handled at runtime, and ensures that a + transparent failover to the backup path(s) happens if a IO errors + arrives on the primary path. + + If unsure, say N. + +config MD_FAULTY + tristate "Faulty test module for MD" + depends on BLK_DEV_MD + help + The "faulty" module allows for a block device that occasionally returns + read or write errors. It is useful for testing. + + In unsure, say N. + +config BLK_DEV_DM + tristate "Device mapper support" + ---help--- + Device-mapper is a low level volume manager. It works by allowing + people to specify mappings for ranges of logical sectors. Various + mapping types are available, in addition people may write their own + modules containing custom mappings if they wish. + + Higher level volume managers such as LVM2 use this driver. + + To compile this as a module, choose M here: the module will be + called dm-mod. + + If unsure, say N. + +config DM_DEBUG + boolean "Device mapper debugging support" + depends on BLK_DEV_DM + ---help--- + Enable this for messages that may help debug device-mapper problems. + + If unsure, say N. + +config DM_CRYPT + tristate "Crypt target support" + depends on BLK_DEV_DM + select CRYPTO + select CRYPTO_CBC + ---help--- + This device-mapper target allows you to create a device that + transparently encrypts the data on it. You'll need to activate + the ciphers you're going to use in the cryptoapi configuration. + + Information on how to use dm-crypt can be found on + + <http://www.saout.de/misc/dm-crypt/> + + To compile this code as a module, choose M here: the module will + be called dm-crypt. + + If unsure, say N. + +config DM_SNAPSHOT + tristate "Snapshot target" + depends on BLK_DEV_DM + ---help--- + Allow volume managers to take writable snapshots of a device. + +config DM_MIRROR + tristate "Mirror target" + depends on BLK_DEV_DM + ---help--- + Allow volume managers to mirror logical volumes, also + needed for live data migration tools such as 'pvmove'. + +config DM_ZERO + tristate "Zero target" + depends on BLK_DEV_DM + ---help--- + A target that discards writes, and returns all zeroes for + reads. Useful in some recovery situations. + +config DM_MULTIPATH + tristate "Multipath target" + depends on BLK_DEV_DM + # nasty syntax but means make DM_MULTIPATH independent + # of SCSI_DH if the latter isn't defined but if + # it is, DM_MULTIPATH must depend on it. We get a build + # error if SCSI_DH=m and DM_MULTIPATH=y + depends on SCSI_DH || !SCSI_DH + ---help--- + Allow volume managers to support multipath hardware. + +config DM_DELAY + tristate "I/O delaying target (EXPERIMENTAL)" + depends on BLK_DEV_DM && EXPERIMENTAL + ---help--- + A target that delays reads and/or writes and can send + them to different devices. Useful for testing. + + If unsure, say N. + +config DM_UEVENT + bool "DM uevents (EXPERIMENTAL)" + depends on BLK_DEV_DM && EXPERIMENTAL + ---help--- + Generate udev events for DM events. + +endif # MD |