1# 2# Block device driver configuration 3# 4 5menu "Multi-device support (RAID and LVM)" 6 7config MD 8 bool "Multiple devices driver support (RAID and LVM)" 9 help 10 Support multiple physical spindles through a single logical device. 11 Required for RAID and logical volume management. 12 13config BLK_DEV_MD 14 tristate "RAID support" 15 depends on MD 16 ---help--- 17 This driver lets you combine several hard disk partitions into one 18 logical block device. This can be used to simply append one 19 partition to another one or to combine several redundant hard disks 20 into a RAID1/4/5 device so as to provide protection against hard 21 disk failures. This is called "Software RAID" since the combining of 22 the partitions is done by the kernel. "Hardware RAID" means that the 23 combining is done by a dedicated controller; if you have such a 24 controller, you do not need to say Y here. 25 26 More information about Software RAID on Linux is contained in the 27 Software RAID mini-HOWTO, available from 28 <http://www.tldp.org/docs.html#howto>. There you will also learn 29 where to get the supporting user space utilities raidtools. 30 31 If unsure, say N. 32 33config MD_LINEAR 34 tristate "Linear (append) mode" 35 depends on BLK_DEV_MD 36 ---help--- 37 If you say Y here, then your multiple devices driver will be able to 38 use the so-called linear mode, i.e. it will combine the hard disk 39 partitions by simply appending one to the other. 40 41 To compile this as a module, choose M here: the module 42 will be called linear. 43 44 If unsure, say Y. 45 46config MD_RAID0 47 tristate "RAID-0 (striping) mode" 48 depends on BLK_DEV_MD 49 ---help--- 50 If you say Y here, then your multiple devices driver will be able to 51 use the so-called raid0 mode, i.e. it will combine the hard disk 52 partitions into one logical device in such a fashion as to fill them 53 up evenly, one chunk here and one chunk there. This will increase 54 the throughput rate if the partitions reside on distinct disks. 55 56 Information about Software RAID on Linux is contained in the 57 Software-RAID mini-HOWTO, available from 58 <http://www.tldp.org/docs.html#howto>. There you will also 59 learn where to get the supporting user space utilities raidtools. 60 61 To compile this as a module, choose M here: the module 62 will be called raid0. 63 64 If unsure, say Y. 65 66config MD_RAID1 67 tristate "RAID-1 (mirroring) mode" 68 depends on BLK_DEV_MD 69 ---help--- 70 A RAID-1 set consists of several disk drives which are exact copies 71 of each other. In the event of a mirror failure, the RAID driver 72 will continue to use the operational mirrors in the set, providing 73 an error free MD (multiple device) to the higher levels of the 74 kernel. In a set with N drives, the available space is the capacity 75 of a single drive, and the set protects against a failure of (N - 1) 76 drives. 77 78 Information about Software RAID on Linux is contained in the 79 Software-RAID mini-HOWTO, available from 80 <http://www.tldp.org/docs.html#howto>. There you will also 81 learn where to get the supporting user space utilities raidtools. 82 83 If you want to use such a RAID-1 set, say Y. To compile this code 84 as a module, choose M here: the module will be called raid1. 85 86 If unsure, say Y. 87 88config MD_RAID10 89 tristate "RAID-10 (mirrored striping) mode (EXPERIMENTAL)" 90 depends on BLK_DEV_MD && EXPERIMENTAL 91 ---help--- 92 RAID-10 provides a combination of striping (RAID-0) and 93 mirroring (RAID-1) with easier configuration and more flexable 94 layout. 95 Unlike RAID-0, but like RAID-1, RAID-10 requires all devices to 96 be the same size (or at least, only as much as the smallest device 97 will be used). 98 RAID-10 provides a variety of layouts that provide different levels 99 of redundancy and performance. 100 101 RAID-10 requires mdadm-1.7.0 or later, available at: 102 103 ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/ 104 105 If unsure, say Y. 106 107config MD_RAID5 108 tristate "RAID-4/RAID-5 mode" 109 depends on BLK_DEV_MD 110 ---help--- 111 A RAID-5 set of N drives with a capacity of C MB per drive provides 112 the capacity of C * (N - 1) MB, and protects against a failure 113 of a single drive. For a given sector (row) number, (N - 1) drives 114 contain data sectors, and one drive contains the parity protection. 115 For a RAID-4 set, the parity blocks are present on a single drive, 116 while a RAID-5 set distributes the parity across the drives in one 117 of the available parity distribution methods. 118 119 Information about Software RAID on Linux is contained in the 120 Software-RAID mini-HOWTO, available from 121 <http://www.tldp.org/docs.html#howto>. There you will also 122 learn where to get the supporting user space utilities raidtools. 123 124 If you want to use such a RAID-4/RAID-5 set, say Y. To 125 compile this code as a module, choose M here: the module 126 will be called raid5. 127 128 If unsure, say Y. 129 130config MD_RAID6 131 tristate "RAID-6 mode" 132 depends on BLK_DEV_MD 133 ---help--- 134 A RAID-6 set of N drives with a capacity of C MB per drive 135 provides the capacity of C * (N - 2) MB, and protects 136 against a failure of any two drives. For a given sector 137 (row) number, (N - 2) drives contain data sectors, and two 138 drives contains two independent redundancy syndromes. Like 139 RAID-5, RAID-6 distributes the syndromes across the drives 140 in one of the available parity distribution methods. 141 142 RAID-6 requires mdadm-1.5.0 or later, available at: 143 144 ftp://ftp.kernel.org/pub/linux/utils/raid/mdadm/ 145 146 If you want to use such a RAID-6 set, say Y. To compile 147 this code as a module, choose M here: the module will be 148 called raid6. 149 150 If unsure, say Y. 151 152config MD_MULTIPATH 153 tristate "Multipath I/O support" 154 depends on BLK_DEV_MD 155 help 156 Multipath-IO is the ability of certain devices to address the same 157 physical disk over multiple 'IO paths'. The code ensures that such 158 paths can be defined and handled at runtime, and ensures that a 159 transparent failover to the backup path(s) happens if a IO errors 160 arrives on the primary path. 161 162 If unsure, say N. 163 164config MD_FAULTY 165 tristate "Faulty test module for MD" 166 depends on BLK_DEV_MD 167 help 168 The "faulty" module allows for a block device that occasionally returns 169 read or write errors. It is useful for testing. 170 171 In unsure, say N. 172 173config BLK_DEV_DM 174 tristate "Device mapper support" 175 depends on MD 176 ---help--- 177 Device-mapper is a low level volume manager. It works by allowing 178 people to specify mappings for ranges of logical sectors. Various 179 mapping types are available, in addition people may write their own 180 modules containing custom mappings if they wish. 181 182 Higher level volume managers such as LVM2 use this driver. 183 184 To compile this as a module, choose M here: the module will be 185 called dm-mod. 186 187 If unsure, say N. 188 189config DM_CRYPT 190 tristate "Crypt target support" 191 depends on BLK_DEV_DM && EXPERIMENTAL 192 select CRYPTO 193 ---help--- 194 This device-mapper target allows you to create a device that 195 transparently encrypts the data on it. You'll need to activate 196 the ciphers you're going to use in the cryptoapi configuration. 197 198 Information on how to use dm-crypt can be found on 199 200 <http://www.saout.de/misc/dm-crypt/> 201 202 To compile this code as a module, choose M here: the module will 203 be called dm-crypt. 204 205 If unsure, say N. 206 207config DM_SNAPSHOT 208 tristate "Snapshot target (EXPERIMENTAL)" 209 depends on BLK_DEV_DM && EXPERIMENTAL 210 ---help--- 211 Allow volume managers to take writeable snapshots of a device. 212 213config DM_MIRROR 214 tristate "Mirror target (EXPERIMENTAL)" 215 depends on BLK_DEV_DM && EXPERIMENTAL 216 ---help--- 217 Allow volume managers to mirror logical volumes, also 218 needed for live data migration tools such as 'pvmove'. 219 220config DM_ZERO 221 tristate "Zero target (EXPERIMENTAL)" 222 depends on BLK_DEV_DM && EXPERIMENTAL 223 ---help--- 224 A target that discards writes, and returns all zeroes for 225 reads. Useful in some recovery situations. 226 227config DM_MULTIPATH 228 tristate "Multipath target (EXPERIMENTAL)" 229 depends on BLK_DEV_DM && EXPERIMENTAL 230 ---help--- 231 Allow volume managers to support multipath hardware. 232 233config DM_MULTIPATH_EMC 234 tristate "EMC CX/AX multipath support (EXPERIMENTAL)" 235 depends on DM_MULTIPATH && BLK_DEV_DM && EXPERIMENTAL 236 ---help--- 237 Multipath support for EMC CX/AX series hardware. 238 239endmenu 240 241