1 Linux Driver for Mylex DAC960/AcceleRAID/eXtremeRAID PCI RAID Controllers 2 3 Version 2.2.11 for Linux 2.2.19 4 Version 2.4.11 for Linux 2.4.12 5 6 PRODUCTION RELEASE 7 8 11 October 2001 9 10 Leonard N. Zubkoff 11 Dandelion Digital 12 lnz@dandelion.com 13 14 Copyright 1998-2001 by Leonard N. Zubkoff <lnz@dandelion.com> 15 16 17 INTRODUCTION 18 19Mylex, Inc. designs and manufactures a variety of high performance PCI RAID 20controllers. Mylex Corporation is located at 34551 Ardenwood Blvd., Fremont, 21California 94555, USA and can be reached at 510.796.6100 or on the World Wide 22Web at http://www.mylex.com. Mylex Technical Support can be reached by 23electronic mail at mylexsup@us.ibm.com, by voice at 510.608.2400, or by FAX at 24510.745.7715. Contact information for offices in Europe and Japan is available 25on their Web site. 26 27The latest information on Linux support for DAC960 PCI RAID Controllers, as 28well as the most recent release of this driver, will always be available from 29my Linux Home Page at URL "http://www.dandelion.com/Linux/". The Linux DAC960 30driver supports all current Mylex PCI RAID controllers including the new 31eXtremeRAID 2000/3000 and AcceleRAID 352/170/160 models which have an entirely 32new firmware interface from the older eXtremeRAID 1100, AcceleRAID 150/200/250, 33and DAC960PJ/PG/PU/PD/PL. See below for a complete controller list as well as 34minimum firmware version requirements. For simplicity, in most places this 35documentation refers to DAC960 generically rather than explicitly listing all 36the supported models. 37 38Driver bug reports should be sent via electronic mail to "lnz@dandelion.com". 39Please include with the bug report the complete configuration messages reported 40by the driver at startup, along with any subsequent system messages relevant to 41the controller's operation, and a detailed description of your system's 42hardware configuration. Driver bugs are actually quite rare; if you encounter 43problems with disks being marked offline, for example, please contact Mylex 44Technical Support as the problem is related to the hardware configuration 45rather than the Linux driver. 46 47Please consult the RAID controller documentation for detailed information 48regarding installation and configuration of the controllers. This document 49primarily provides information specific to the Linux support. 50 51 52 DRIVER FEATURES 53 54The DAC960 RAID controllers are supported solely as high performance RAID 55controllers, not as interfaces to arbitrary SCSI devices. The Linux DAC960 56driver operates at the block device level, the same level as the SCSI and IDE 57drivers. Unlike other RAID controllers currently supported on Linux, the 58DAC960 driver is not dependent on the SCSI subsystem, and hence avoids all the 59complexity and unnecessary code that would be associated with an implementation 60as a SCSI driver. The DAC960 driver is designed for as high a performance as 61possible with no compromises or extra code for compatibility with lower 62performance devices. The DAC960 driver includes extensive error logging and 63online configuration management capabilities. Except for initial configuration 64of the controller and adding new disk drives, most everything can be handled 65from Linux while the system is operational. 66 67The DAC960 driver is architected to support up to 8 controllers per system. 68Each DAC960 parallel SCSI controller can support up to 15 disk drives per 69channel, for a maximum of 60 drives on a four channel controller; the fibre 70channel eXtremeRAID 3000 controller supports up to 125 disk drives per loop for 71a total of 250 drives. The drives installed on a controller are divided into 72one or more "Drive Groups", and then each Drive Group is subdivided further 73into 1 to 32 "Logical Drives". Each Logical Drive has a specific RAID Level 74and caching policy associated with it, and it appears to Linux as a single 75block device. Logical Drives are further subdivided into up to 7 partitions 76through the normal Linux and PC disk partitioning schemes. Logical Drives are 77also known as "System Drives", and Drive Groups are also called "Packs". Both 78terms are in use in the Mylex documentation; I have chosen to standardize on 79the more generic "Logical Drive" and "Drive Group". 80 81DAC960 RAID disk devices are named in the style of the Device File System 82(DEVFS). The device corresponding to Logical Drive D on Controller C is 83referred to as /dev/rd/cCdD, and the partitions are called /dev/rd/cCdDp1 84through /dev/rd/cCdDp7. For example, partition 3 of Logical Drive 5 on 85Controller 2 is referred to as /dev/rd/c2d5p3. Note that unlike with SCSI 86disks the device names will not change in the event of a disk drive failure. 87The DAC960 driver is assigned major numbers 48 - 55 with one major number per 88controller. The 8 bits of minor number are divided into 5 bits for the Logical 89Drive and 3 bits for the partition. 90 91 92 SUPPORTED DAC960/AcceleRAID/eXtremeRAID PCI RAID CONTROLLERS 93 94The following list comprises the supported DAC960, AcceleRAID, and eXtremeRAID 95PCI RAID Controllers as of the date of this document. It is recommended that 96anyone purchasing a Mylex PCI RAID Controller not in the following table 97contact the author beforehand to verify that it is or will be supported. 98 99eXtremeRAID 3000 100 1 Wide Ultra-2/LVD SCSI channel 101 2 External Fibre FC-AL channels 102 233MHz StrongARM SA 110 Processor 103 64 Bit 33MHz PCI (backward compatible with 32 Bit PCI slots) 104 32MB/64MB ECC SDRAM Memory 105 106eXtremeRAID 2000 107 4 Wide Ultra-160 LVD SCSI channels 108 233MHz StrongARM SA 110 Processor 109 64 Bit 33MHz PCI (backward compatible with 32 Bit PCI slots) 110 32MB/64MB ECC SDRAM Memory 111 112AcceleRAID 352 113 2 Wide Ultra-160 LVD SCSI channels 114 100MHz Intel i960RN RISC Processor 115 64 Bit 33MHz PCI (backward compatible with 32 Bit PCI slots) 116 32MB/64MB ECC SDRAM Memory 117 118AcceleRAID 170 119 1 Wide Ultra-160 LVD SCSI channel 120 100MHz Intel i960RM RISC Processor 121 16MB/32MB/64MB ECC SDRAM Memory 122 123AcceleRAID 160 (AcceleRAID 170LP) 124 1 Wide Ultra-160 LVD SCSI channel 125 100MHz Intel i960RS RISC Processor 126 Built in 16M ECC SDRAM Memory 127 PCI Low Profile Form Factor - fit for 2U height 128 129eXtremeRAID 1100 (DAC1164P) 130 3 Wide Ultra-2/LVD SCSI channels 131 233MHz StrongARM SA 110 Processor 132 64 Bit 33MHz PCI (backward compatible with 32 Bit PCI slots) 133 16MB/32MB/64MB Parity SDRAM Memory with Battery Backup 134 135AcceleRAID 250 (DAC960PTL1) 136 Uses onboard Symbios SCSI chips on certain motherboards 137 Also includes one onboard Wide Ultra-2/LVD SCSI Channel 138 66MHz Intel i960RD RISC Processor 139 4MB/8MB/16MB/32MB/64MB/128MB ECC EDO Memory 140 141AcceleRAID 200 (DAC960PTL0) 142 Uses onboard Symbios SCSI chips on certain motherboards 143 Includes no onboard SCSI Channels 144 66MHz Intel i960RD RISC Processor 145 4MB/8MB/16MB/32MB/64MB/128MB ECC EDO Memory 146 147AcceleRAID 150 (DAC960PRL) 148 Uses onboard Symbios SCSI chips on certain motherboards 149 Also includes one onboard Wide Ultra-2/LVD SCSI Channel 150 33MHz Intel i960RP RISC Processor 151 4MB Parity EDO Memory 152 153DAC960PJ 1/2/3 Wide Ultra SCSI-3 Channels 154 66MHz Intel i960RD RISC Processor 155 4MB/8MB/16MB/32MB/64MB/128MB ECC EDO Memory 156 157DAC960PG 1/2/3 Wide Ultra SCSI-3 Channels 158 33MHz Intel i960RP RISC Processor 159 4MB/8MB ECC EDO Memory 160 161DAC960PU 1/2/3 Wide Ultra SCSI-3 Channels 162 Intel i960CF RISC Processor 163 4MB/8MB EDRAM or 2MB/4MB/8MB/16MB/32MB DRAM Memory 164 165DAC960PD 1/2/3 Wide Fast SCSI-2 Channels 166 Intel i960CF RISC Processor 167 4MB/8MB EDRAM or 2MB/4MB/8MB/16MB/32MB DRAM Memory 168 169DAC960PL 1/2/3 Wide Fast SCSI-2 Channels 170 Intel i960 RISC Processor 171 2MB/4MB/8MB/16MB/32MB DRAM Memory 172 173DAC960P 1/2/3 Wide Fast SCSI-2 Channels 174 Intel i960 RISC Processor 175 2MB/4MB/8MB/16MB/32MB DRAM Memory 176 177For the eXtremeRAID 2000/3000 and AcceleRAID 352/170/160, firmware version 1786.00-01 or above is required. 179 180For the eXtremeRAID 1100, firmware version 5.06-0-52 or above is required. 181 182For the AcceleRAID 250, 200, and 150, firmware version 4.06-0-57 or above is 183required. 184 185For the DAC960PJ and DAC960PG, firmware version 4.06-0-00 or above is required. 186 187For the DAC960PU, DAC960PD, DAC960PL, and DAC960P, either firmware version 1883.51-0-04 or above is required (for dual Flash ROM controllers), or firmware 189version 2.73-0-00 or above is required (for single Flash ROM controllers) 190 191Please note that not all SCSI disk drives are suitable for use with DAC960 192controllers, and only particular firmware versions of any given model may 193actually function correctly. Similarly, not all motherboards have a BIOS that 194properly initializes the AcceleRAID 250, AcceleRAID 200, AcceleRAID 150, 195DAC960PJ, and DAC960PG because the Intel i960RD/RP is a multi-function device. 196If in doubt, contact Mylex RAID Technical Support (mylexsup@us.ibm.com) to 197verify compatibility. Mylex makes available a hard disk compatibility list at 198http://www.mylex.com/support/hdcomp/hd-lists.html. 199 200 201 DRIVER INSTALLATION 202 203This distribution was prepared for Linux kernel version 2.2.19 or 2.4.12. 204 205To install the DAC960 RAID driver, you may use the following commands, 206replacing "/usr/src" with wherever you keep your Linux kernel source tree: 207 208 cd /usr/src 209 tar -xvzf DAC960-2.2.11.tar.gz (or DAC960-2.4.11.tar.gz) 210 mv README.DAC960 linux/Documentation 211 mv DAC960.[ch] linux/drivers/block 212 patch -p0 < DAC960.patch (if DAC960.patch is included) 213 cd linux 214 make config 215 make depend 216 make bzImage (or zImage) 217 218Then install "arch/i386/boot/bzImage" or "arch/i386/boot/zImage" as your 219standard kernel, run lilo if appropriate, and reboot. 220 221To create the necessary devices in /dev, the "make_rd" script included in 222"DAC960-Utilities.tar.gz" from http://www.dandelion.com/Linux/ may be used. 223LILO 21 and FDISK v2.9 include DAC960 support; also included in this archive 224are patches to LILO 20 and FDISK v2.8 that add DAC960 support, along with 225statically linked executables of LILO and FDISK. This modified version of LILO 226will allow booting from a DAC960 controller and/or mounting the root file 227system from a DAC960. 228 229Red Hat Linux 6.0 and SuSE Linux 6.1 include support for Mylex PCI RAID 230controllers. Installing directly onto a DAC960 may be problematic from other 231Linux distributions until their installation utilities are updated. 232 233 234 INSTALLATION NOTES 235 236Before installing Linux or adding DAC960 logical drives to an existing Linux 237system, the controller must first be configured to provide one or more logical 238drives using the BIOS Configuration Utility or DACCF. Please note that since 239there are only at most 6 usable partitions on each logical drive, systems 240requiring more partitions should subdivide a drive group into multiple logical 241drives, each of which can have up to 6 usable partitions. Also, note that with 242large disk arrays it is advisable to enable the 8GB BIOS Geometry (255/63) 243rather than accepting the default 2GB BIOS Geometry (128/32); failing to so do 244will cause the logical drive geometry to have more than 65535 cylinders which 245will make it impossible for FDISK to be used properly. The 8GB BIOS Geometry 246can be enabled by configuring the DAC960 BIOS, which is accessible via Alt-M 247during the BIOS initialization sequence. 248 249For maximum performance and the most efficient E2FSCK performance, it is 250recommended that EXT2 file systems be built with a 4KB block size and 16 block 251stride to match the DAC960 controller's 64KB default stripe size. The command 252"mke2fs -b 4096 -R stride=16 <device>" is appropriate. Unless there will be a 253large number of small files on the file systems, it is also beneficial to add 254the "-i 16384" option to increase the bytes per inode parameter thereby 255reducing the file system metadata. Finally, on systems that will only be run 256with Linux 2.2 or later kernels it is beneficial to enable sparse superblocks 257with the "-s 1" option. 258 259 260 DAC960 ANNOUNCEMENTS MAILING LIST 261 262The DAC960 Announcements Mailing List provides a forum for informing Linux 263users of new driver releases and other announcements regarding Linux support 264for DAC960 PCI RAID Controllers. To join the mailing list, send a message to 265"dac960-announce-request@dandelion.com" with the line "subscribe" in the 266message body. 267 268 269 CONTROLLER CONFIGURATION AND STATUS MONITORING 270 271The DAC960 RAID controllers running firmware 4.06 or above include a Background 272Initialization facility so that system downtime is minimized both for initial 273installation and subsequent configuration of additional storage. The BIOS 274Configuration Utility (accessible via Alt-R during the BIOS initialization 275sequence) is used to quickly configure the controller, and then the logical 276drives that have been created are available for immediate use even while they 277are still being initialized by the controller. The primary need for online 278configuration and status monitoring is then to avoid system downtime when disk 279drives fail and must be replaced. Mylex's online monitoring and configuration 280utilities are being ported to Linux and will become available at some point in 281the future. Note that with a SAF-TE (SCSI Accessed Fault-Tolerant Enclosure) 282enclosure, the controller is able to rebuild failed drives automatically as 283soon as a drive replacement is made available. 284 285The primary interfaces for controller configuration and status monitoring are 286special files created in the /proc/rd/... hierarchy along with the normal 287system console logging mechanism. Whenever the system is operating, the DAC960 288driver queries each controller for status information every 10 seconds, and 289checks for additional conditions every 60 seconds. The initial status of each 290controller is always available for controller N in /proc/rd/cN/initial_status, 291and the current status as of the last status monitoring query is available in 292/proc/rd/cN/current_status. In addition, status changes are also logged by the 293driver to the system console and will appear in the log files maintained by 294syslog. The progress of asynchronous rebuild or consistency check operations 295is also available in /proc/rd/cN/current_status, and progress messages are 296logged to the system console at most every 60 seconds. 297 298Starting with the 2.2.3/2.0.3 versions of the driver, the status information 299available in /proc/rd/cN/initial_status and /proc/rd/cN/current_status has been 300augmented to include the vendor, model, revision, and serial number (if 301available) for each physical device found connected to the controller: 302 303***** DAC960 RAID Driver Version 2.2.3 of 19 August 1999 ***** 304Copyright 1998-1999 by Leonard N. Zubkoff <lnz@dandelion.com> 305Configuring Mylex DAC960PRL PCI RAID Controller 306 Firmware Version: 4.07-0-07, Channels: 1, Memory Size: 16MB 307 PCI Bus: 1, Device: 4, Function: 1, I/O Address: Unassigned 308 PCI Address: 0xFE300000 mapped at 0xA0800000, IRQ Channel: 21 309 Controller Queue Depth: 128, Maximum Blocks per Command: 128 310 Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33 311 Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63 312 SAF-TE Enclosure Management Enabled 313 Physical Devices: 314 0:0 Vendor: IBM Model: DRVS09D Revision: 0270 315 Serial Number: 68016775HA 316 Disk Status: Online, 17928192 blocks 317 0:1 Vendor: IBM Model: DRVS09D Revision: 0270 318 Serial Number: 68004E53HA 319 Disk Status: Online, 17928192 blocks 320 0:2 Vendor: IBM Model: DRVS09D Revision: 0270 321 Serial Number: 13013935HA 322 Disk Status: Online, 17928192 blocks 323 0:3 Vendor: IBM Model: DRVS09D Revision: 0270 324 Serial Number: 13016897HA 325 Disk Status: Online, 17928192 blocks 326 0:4 Vendor: IBM Model: DRVS09D Revision: 0270 327 Serial Number: 68019905HA 328 Disk Status: Online, 17928192 blocks 329 0:5 Vendor: IBM Model: DRVS09D Revision: 0270 330 Serial Number: 68012753HA 331 Disk Status: Online, 17928192 blocks 332 0:6 Vendor: ESG-SHV Model: SCA HSBP M6 Revision: 0.61 333 Logical Drives: 334 /dev/rd/c0d0: RAID-5, Online, 89640960 blocks, Write Thru 335 No Rebuild or Consistency Check in Progress 336 337To simplify the monitoring process for custom software, the special file 338/proc/rd/status returns "OK" when all DAC960 controllers in the system are 339operating normally and no failures have occurred, or "ALERT" if any logical 340drives are offline or critical or any non-standby physical drives are dead. 341 342Configuration commands for controller N are available via the special file 343/proc/rd/cN/user_command. A human readable command can be written to this 344special file to initiate a configuration operation, and the results of the 345operation can then be read back from the special file in addition to being 346logged to the system console. The shell command sequence 347 348 echo "<configuration-command>" > /proc/rd/c0/user_command 349 cat /proc/rd/c0/user_command 350 351is typically used to execute configuration commands. The configuration 352commands are: 353 354 flush-cache 355 356 The "flush-cache" command flushes the controller's cache. The system 357 automatically flushes the cache at shutdown or if the driver module is 358 unloaded, so this command is only needed to be certain a write back cache 359 is flushed to disk before the system is powered off by a command to a UPS. 360 Note that the flush-cache command also stops an asynchronous rebuild or 361 consistency check, so it should not be used except when the system is being 362 halted. 363 364 kill <channel>:<target-id> 365 366 The "kill" command marks the physical drive <channel>:<target-id> as DEAD. 367 This command is provided primarily for testing, and should not be used 368 during normal system operation. 369 370 make-online <channel>:<target-id> 371 372 The "make-online" command changes the physical drive <channel>:<target-id> 373 from status DEAD to status ONLINE. In cases where multiple physical drives 374 have been killed simultaneously, this command may be used to bring all but 375 one of them back online, after which a rebuild to the final drive is 376 necessary. 377 378 Warning: make-online should only be used on a dead physical drive that is 379 an active part of a drive group, never on a standby drive. The command 380 should never be used on a dead drive that is part of a critical logical 381 drive; rebuild should be used if only a single drive is dead. 382 383 make-standby <channel>:<target-id> 384 385 The "make-standby" command changes physical drive <channel>:<target-id> 386 from status DEAD to status STANDBY. It should only be used in cases where 387 a dead drive was replaced after an automatic rebuild was performed onto a 388 standby drive. It cannot be used to add a standby drive to the controller 389 configuration if one was not created initially; the BIOS Configuration 390 Utility must be used for that currently. 391 392 rebuild <channel>:<target-id> 393 394 The "rebuild" command initiates an asynchronous rebuild onto physical drive 395 <channel>:<target-id>. It should only be used when a dead drive has been 396 replaced. 397 398 check-consistency <logical-drive-number> 399 400 The "check-consistency" command initiates an asynchronous consistency check 401 of <logical-drive-number> with automatic restoration. It can be used 402 whenever it is desired to verify the consistency of the redundancy 403 information. 404 405 cancel-rebuild 406 cancel-consistency-check 407 408 The "cancel-rebuild" and "cancel-consistency-check" commands cancel any 409 rebuild or consistency check operations previously initiated. 410 411 412 EXAMPLE I - DRIVE FAILURE WITHOUT A STANDBY DRIVE 413 414The following annotated logs demonstrate the controller configuration and and 415online status monitoring capabilities of the Linux DAC960 Driver. The test 416configuration comprises 6 1GB Quantum Atlas I disk drives on two channels of a 417DAC960PJ controller. The physical drives are configured into a single drive 418group without a standby drive, and the drive group has been configured into two 419logical drives, one RAID-5 and one RAID-6. Note that these logs are from an 420earlier version of the driver and the messages have changed somewhat with newer 421releases, but the functionality remains similar. First, here is the current 422status of the RAID configuration: 423 424gwynedd:/u/lnz# cat /proc/rd/c0/current_status 425***** DAC960 RAID Driver Version 2.0.0 of 23 March 1999 ***** 426Copyright 1998-1999 by Leonard N. Zubkoff <lnz@dandelion.com> 427Configuring Mylex DAC960PJ PCI RAID Controller 428 Firmware Version: 4.06-0-08, Channels: 3, Memory Size: 8MB 429 PCI Bus: 0, Device: 19, Function: 1, I/O Address: Unassigned 430 PCI Address: 0xFD4FC000 mapped at 0x8807000, IRQ Channel: 9 431 Controller Queue Depth: 128, Maximum Blocks per Command: 128 432 Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33 433 Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63 434 Physical Devices: 435 0:1 - Disk: Online, 2201600 blocks 436 0:2 - Disk: Online, 2201600 blocks 437 0:3 - Disk: Online, 2201600 blocks 438 1:1 - Disk: Online, 2201600 blocks 439 1:2 - Disk: Online, 2201600 blocks 440 1:3 - Disk: Online, 2201600 blocks 441 Logical Drives: 442 /dev/rd/c0d0: RAID-5, Online, 5498880 blocks, Write Thru 443 /dev/rd/c0d1: RAID-6, Online, 3305472 blocks, Write Thru 444 No Rebuild or Consistency Check in Progress 445 446gwynedd:/u/lnz# cat /proc/rd/status 447OK 448 449The above messages indicate that everything is healthy, and /proc/rd/status 450returns "OK" indicating that there are no problems with any DAC960 controller 451in the system. For demonstration purposes, while I/O is active Physical Drive 4521:1 is now disconnected, simulating a drive failure. The failure is noted by 453the driver within 10 seconds of the controller's having detected it, and the 454driver logs the following console status messages indicating that Logical 455Drives 0 and 1 are now CRITICAL as a result of Physical Drive 1:1 being DEAD: 456 457DAC960#0: Physical Drive 1:2 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02 458DAC960#0: Physical Drive 1:3 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02 459DAC960#0: Physical Drive 1:1 killed because of timeout on SCSI command 460DAC960#0: Physical Drive 1:1 is now DEAD 461DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now CRITICAL 462DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now CRITICAL 463 464The Sense Keys logged here are just Check Condition / Unit Attention conditions 465arising from a SCSI bus reset that is forced by the controller during its error 466recovery procedures. Concurrently with the above, the driver status available 467from /proc/rd also reflects the drive failure. The status message in 468/proc/rd/status has changed from "OK" to "ALERT": 469 470gwynedd:/u/lnz# cat /proc/rd/status 471ALERT 472 473and /proc/rd/c0/current_status has been updated: 474 475gwynedd:/u/lnz# cat /proc/rd/c0/current_status 476 ... 477 Physical Devices: 478 0:1 - Disk: Online, 2201600 blocks 479 0:2 - Disk: Online, 2201600 blocks 480 0:3 - Disk: Online, 2201600 blocks 481 1:1 - Disk: Dead, 2201600 blocks 482 1:2 - Disk: Online, 2201600 blocks 483 1:3 - Disk: Online, 2201600 blocks 484 Logical Drives: 485 /dev/rd/c0d0: RAID-5, Critical, 5498880 blocks, Write Thru 486 /dev/rd/c0d1: RAID-6, Critical, 3305472 blocks, Write Thru 487 No Rebuild or Consistency Check in Progress 488 489Since there are no standby drives configured, the system can continue to access 490the logical drives in a performance degraded mode until the failed drive is 491replaced and a rebuild operation completed to restore the redundancy of the 492logical drives. Once Physical Drive 1:1 is replaced with a properly 493functioning drive, or if the physical drive was killed without having failed 494(e.g., due to electrical problems on the SCSI bus), the user can instruct the 495controller to initiate a rebuild operation onto the newly replaced drive: 496 497gwynedd:/u/lnz# echo "rebuild 1:1" > /proc/rd/c0/user_command 498gwynedd:/u/lnz# cat /proc/rd/c0/user_command 499Rebuild of Physical Drive 1:1 Initiated 500 501The echo command instructs the controller to initiate an asynchronous rebuild 502operation onto Physical Drive 1:1, and the status message that results from the 503operation is then available for reading from /proc/rd/c0/user_command, as well 504as being logged to the console by the driver. 505 506Within 10 seconds of this command the driver logs the initiation of the 507asynchronous rebuild operation: 508 509DAC960#0: Rebuild of Physical Drive 1:1 Initiated 510DAC960#0: Physical Drive 1:1 Error Log: Sense Key = 6, ASC = 29, ASCQ = 01 511DAC960#0: Physical Drive 1:1 is now WRITE-ONLY 512DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 1% completed 513 514and /proc/rd/c0/current_status is updated: 515 516gwynedd:/u/lnz# cat /proc/rd/c0/current_status 517 ... 518 Physical Devices: 519 0:1 - Disk: Online, 2201600 blocks 520 0:2 - Disk: Online, 2201600 blocks 521 0:3 - Disk: Online, 2201600 blocks 522 1:1 - Disk: Write-Only, 2201600 blocks 523 1:2 - Disk: Online, 2201600 blocks 524 1:3 - Disk: Online, 2201600 blocks 525 Logical Drives: 526 /dev/rd/c0d0: RAID-5, Critical, 5498880 blocks, Write Thru 527 /dev/rd/c0d1: RAID-6, Critical, 3305472 blocks, Write Thru 528 Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 6% completed 529 530As the rebuild progresses, the current status in /proc/rd/c0/current_status is 531updated every 10 seconds: 532 533gwynedd:/u/lnz# cat /proc/rd/c0/current_status 534 ... 535 Physical Devices: 536 0:1 - Disk: Online, 2201600 blocks 537 0:2 - Disk: Online, 2201600 blocks 538 0:3 - Disk: Online, 2201600 blocks 539 1:1 - Disk: Write-Only, 2201600 blocks 540 1:2 - Disk: Online, 2201600 blocks 541 1:3 - Disk: Online, 2201600 blocks 542 Logical Drives: 543 /dev/rd/c0d0: RAID-5, Critical, 5498880 blocks, Write Thru 544 /dev/rd/c0d1: RAID-6, Critical, 3305472 blocks, Write Thru 545 Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 15% completed 546 547and every minute a progress message is logged to the console by the driver: 548 549DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 32% completed 550DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 63% completed 551DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 94% completed 552DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 94% completed 553 554Finally, the rebuild completes successfully. The driver logs the status of the 555logical and physical drives and the rebuild completion: 556 557DAC960#0: Rebuild Completed Successfully 558DAC960#0: Physical Drive 1:1 is now ONLINE 559DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now ONLINE 560DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now ONLINE 561 562/proc/rd/c0/current_status is updated: 563 564gwynedd:/u/lnz# cat /proc/rd/c0/current_status 565 ... 566 Physical Devices: 567 0:1 - Disk: Online, 2201600 blocks 568 0:2 - Disk: Online, 2201600 blocks 569 0:3 - Disk: Online, 2201600 blocks 570 1:1 - Disk: Online, 2201600 blocks 571 1:2 - Disk: Online, 2201600 blocks 572 1:3 - Disk: Online, 2201600 blocks 573 Logical Drives: 574 /dev/rd/c0d0: RAID-5, Online, 5498880 blocks, Write Thru 575 /dev/rd/c0d1: RAID-6, Online, 3305472 blocks, Write Thru 576 Rebuild Completed Successfully 577 578and /proc/rd/status indicates that everything is healthy once again: 579 580gwynedd:/u/lnz# cat /proc/rd/status 581OK 582 583 584 EXAMPLE II - DRIVE FAILURE WITH A STANDBY DRIVE 585 586The following annotated logs demonstrate the controller configuration and and 587online status monitoring capabilities of the Linux DAC960 Driver. The test 588configuration comprises 6 1GB Quantum Atlas I disk drives on two channels of a 589DAC960PJ controller. The physical drives are configured into a single drive 590group with a standby drive, and the drive group has been configured into two 591logical drives, one RAID-5 and one RAID-6. Note that these logs are from an 592earlier version of the driver and the messages have changed somewhat with newer 593releases, but the functionality remains similar. First, here is the current 594status of the RAID configuration: 595 596gwynedd:/u/lnz# cat /proc/rd/c0/current_status 597***** DAC960 RAID Driver Version 2.0.0 of 23 March 1999 ***** 598Copyright 1998-1999 by Leonard N. Zubkoff <lnz@dandelion.com> 599Configuring Mylex DAC960PJ PCI RAID Controller 600 Firmware Version: 4.06-0-08, Channels: 3, Memory Size: 8MB 601 PCI Bus: 0, Device: 19, Function: 1, I/O Address: Unassigned 602 PCI Address: 0xFD4FC000 mapped at 0x8807000, IRQ Channel: 9 603 Controller Queue Depth: 128, Maximum Blocks per Command: 128 604 Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33 605 Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63 606 Physical Devices: 607 0:1 - Disk: Online, 2201600 blocks 608 0:2 - Disk: Online, 2201600 blocks 609 0:3 - Disk: Online, 2201600 blocks 610 1:1 - Disk: Online, 2201600 blocks 611 1:2 - Disk: Online, 2201600 blocks 612 1:3 - Disk: Standby, 2201600 blocks 613 Logical Drives: 614 /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru 615 /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru 616 No Rebuild or Consistency Check in Progress 617 618gwynedd:/u/lnz# cat /proc/rd/status 619OK 620 621The above messages indicate that everything is healthy, and /proc/rd/status 622returns "OK" indicating that there are no problems with any DAC960 controller 623in the system. For demonstration purposes, while I/O is active Physical Drive 6241:2 is now disconnected, simulating a drive failure. The failure is noted by 625the driver within 10 seconds of the controller's having detected it, and the 626driver logs the following console status messages: 627 628DAC960#0: Physical Drive 1:1 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02 629DAC960#0: Physical Drive 1:3 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02 630DAC960#0: Physical Drive 1:2 killed because of timeout on SCSI command 631DAC960#0: Physical Drive 1:2 is now DEAD 632DAC960#0: Physical Drive 1:2 killed because it was removed 633DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now CRITICAL 634DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now CRITICAL 635 636Since a standby drive is configured, the controller automatically begins 637rebuilding onto the standby drive: 638 639DAC960#0: Physical Drive 1:3 is now WRITE-ONLY 640DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 4% completed 641 642Concurrently with the above, the driver status available from /proc/rd also 643reflects the drive failure and automatic rebuild. The status message in 644/proc/rd/status has changed from "OK" to "ALERT": 645 646gwynedd:/u/lnz# cat /proc/rd/status 647ALERT 648 649and /proc/rd/c0/current_status has been updated: 650 651gwynedd:/u/lnz# cat /proc/rd/c0/current_status 652 ... 653 Physical Devices: 654 0:1 - Disk: Online, 2201600 blocks 655 0:2 - Disk: Online, 2201600 blocks 656 0:3 - Disk: Online, 2201600 blocks 657 1:1 - Disk: Online, 2201600 blocks 658 1:2 - Disk: Dead, 2201600 blocks 659 1:3 - Disk: Write-Only, 2201600 blocks 660 Logical Drives: 661 /dev/rd/c0d0: RAID-5, Critical, 4399104 blocks, Write Thru 662 /dev/rd/c0d1: RAID-6, Critical, 2754560 blocks, Write Thru 663 Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 4% completed 664 665As the rebuild progresses, the current status in /proc/rd/c0/current_status is 666updated every 10 seconds: 667 668gwynedd:/u/lnz# cat /proc/rd/c0/current_status 669 ... 670 Physical Devices: 671 0:1 - Disk: Online, 2201600 blocks 672 0:2 - Disk: Online, 2201600 blocks 673 0:3 - Disk: Online, 2201600 blocks 674 1:1 - Disk: Online, 2201600 blocks 675 1:2 - Disk: Dead, 2201600 blocks 676 1:3 - Disk: Write-Only, 2201600 blocks 677 Logical Drives: 678 /dev/rd/c0d0: RAID-5, Critical, 4399104 blocks, Write Thru 679 /dev/rd/c0d1: RAID-6, Critical, 2754560 blocks, Write Thru 680 Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 40% completed 681 682and every minute a progress message is logged on the console by the driver: 683 684DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 40% completed 685DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 76% completed 686DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 66% completed 687DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 84% completed 688 689Finally, the rebuild completes successfully. The driver logs the status of the 690logical and physical drives and the rebuild completion: 691 692DAC960#0: Rebuild Completed Successfully 693DAC960#0: Physical Drive 1:3 is now ONLINE 694DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now ONLINE 695DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now ONLINE 696 697/proc/rd/c0/current_status is updated: 698 699***** DAC960 RAID Driver Version 2.0.0 of 23 March 1999 ***** 700Copyright 1998-1999 by Leonard N. Zubkoff <lnz@dandelion.com> 701Configuring Mylex DAC960PJ PCI RAID Controller 702 Firmware Version: 4.06-0-08, Channels: 3, Memory Size: 8MB 703 PCI Bus: 0, Device: 19, Function: 1, I/O Address: Unassigned 704 PCI Address: 0xFD4FC000 mapped at 0x8807000, IRQ Channel: 9 705 Controller Queue Depth: 128, Maximum Blocks per Command: 128 706 Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33 707 Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63 708 Physical Devices: 709 0:1 - Disk: Online, 2201600 blocks 710 0:2 - Disk: Online, 2201600 blocks 711 0:3 - Disk: Online, 2201600 blocks 712 1:1 - Disk: Online, 2201600 blocks 713 1:2 - Disk: Dead, 2201600 blocks 714 1:3 - Disk: Online, 2201600 blocks 715 Logical Drives: 716 /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru 717 /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru 718 Rebuild Completed Successfully 719 720and /proc/rd/status indicates that everything is healthy once again: 721 722gwynedd:/u/lnz# cat /proc/rd/status 723OK 724 725Note that the absence of a viable standby drive does not create an "ALERT" 726status. Once dead Physical Drive 1:2 has been replaced, the controller must be 727told that this has occurred and that the newly replaced drive should become the 728new standby drive: 729 730gwynedd:/u/lnz# echo "make-standby 1:2" > /proc/rd/c0/user_command 731gwynedd:/u/lnz# cat /proc/rd/c0/user_command 732Make Standby of Physical Drive 1:2 Succeeded 733 734The echo command instructs the controller to make Physical Drive 1:2 into a 735standby drive, and the status message that results from the operation is then 736available for reading from /proc/rd/c0/user_command, as well as being logged to 737the console by the driver. Within 60 seconds of this command the driver logs: 738 739DAC960#0: Physical Drive 1:2 Error Log: Sense Key = 6, ASC = 29, ASCQ = 01 740DAC960#0: Physical Drive 1:2 is now STANDBY 741DAC960#0: Make Standby of Physical Drive 1:2 Succeeded 742 743and /proc/rd/c0/current_status is updated: 744 745gwynedd:/u/lnz# cat /proc/rd/c0/current_status 746 ... 747 Physical Devices: 748 0:1 - Disk: Online, 2201600 blocks 749 0:2 - Disk: Online, 2201600 blocks 750 0:3 - Disk: Online, 2201600 blocks 751 1:1 - Disk: Online, 2201600 blocks 752 1:2 - Disk: Standby, 2201600 blocks 753 1:3 - Disk: Online, 2201600 blocks 754 Logical Drives: 755 /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru 756 /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru 757 Rebuild Completed Successfully 758