| Linux Driver for Mylex DAC960/AcceleRAID/eXtremeRAID PCI RAID Controllers | |
| Version 2.2.11 for Linux 2.2.19 | |
| Version 2.4.11 for Linux 2.4.12 | |
| PRODUCTION RELEASE | |
| 11 October 2001 | |
| Leonard N. Zubkoff | |
| Dandelion Digital | |
| lnz@dandelion.com | |
| Copyright 1998-2001 by Leonard N. Zubkoff <lnz@dandelion.com> | |
| INTRODUCTION | |
| Mylex, Inc. designs and manufactures a variety of high performance PCI RAID | |
| controllers. Mylex Corporation is located at 34551 Ardenwood Blvd., Fremont, | |
| California 94555, USA and can be reached at 510.796.6100 or on the World Wide | |
| Web at http://www.mylex.com. Mylex Technical Support can be reached by | |
| electronic mail at mylexsup@us.ibm.com, by voice at 510.608.2400, or by FAX at | |
| 510.745.7715. Contact information for offices in Europe and Japan is available | |
| on their Web site. | |
| The latest information on Linux support for DAC960 PCI RAID Controllers, as | |
| well as the most recent release of this driver, will always be available from | |
| my Linux Home Page at URL "http://www.dandelion.com/Linux/". The Linux DAC960 | |
| driver supports all current Mylex PCI RAID controllers including the new | |
| eXtremeRAID 2000/3000 and AcceleRAID 352/170/160 models which have an entirely | |
| new firmware interface from the older eXtremeRAID 1100, AcceleRAID 150/200/250, | |
| and DAC960PJ/PG/PU/PD/PL. See below for a complete controller list as well as | |
| minimum firmware version requirements. For simplicity, in most places this | |
| documentation refers to DAC960 generically rather than explicitly listing all | |
| the supported models. | |
| Driver bug reports should be sent via electronic mail to "lnz@dandelion.com". | |
| Please include with the bug report the complete configuration messages reported | |
| by the driver at startup, along with any subsequent system messages relevant to | |
| the controller's operation, and a detailed description of your system's | |
| hardware configuration. Driver bugs are actually quite rare; if you encounter | |
| problems with disks being marked offline, for example, please contact Mylex | |
| Technical Support as the problem is related to the hardware configuration | |
| rather than the Linux driver. | |
| Please consult the RAID controller documentation for detailed information | |
| regarding installation and configuration of the controllers. This document | |
| primarily provides information specific to the Linux support. | |
| DRIVER FEATURES | |
| The DAC960 RAID controllers are supported solely as high performance RAID | |
| controllers, not as interfaces to arbitrary SCSI devices. The Linux DAC960 | |
| driver operates at the block device level, the same level as the SCSI and IDE | |
| drivers. Unlike other RAID controllers currently supported on Linux, the | |
| DAC960 driver is not dependent on the SCSI subsystem, and hence avoids all the | |
| complexity and unnecessary code that would be associated with an implementation | |
| as a SCSI driver. The DAC960 driver is designed for as high a performance as | |
| possible with no compromises or extra code for compatibility with lower | |
| performance devices. The DAC960 driver includes extensive error logging and | |
| online configuration management capabilities. Except for initial configuration | |
| of the controller and adding new disk drives, most everything can be handled | |
| from Linux while the system is operational. | |
| The DAC960 driver is architected to support up to 8 controllers per system. | |
| Each DAC960 parallel SCSI controller can support up to 15 disk drives per | |
| channel, for a maximum of 60 drives on a four channel controller; the fibre | |
| channel eXtremeRAID 3000 controller supports up to 125 disk drives per loop for | |
| a total of 250 drives. The drives installed on a controller are divided into | |
| one or more "Drive Groups", and then each Drive Group is subdivided further | |
| into 1 to 32 "Logical Drives". Each Logical Drive has a specific RAID Level | |
| and caching policy associated with it, and it appears to Linux as a single | |
| block device. Logical Drives are further subdivided into up to 7 partitions | |
| through the normal Linux and PC disk partitioning schemes. Logical Drives are | |
| also known as "System Drives", and Drive Groups are also called "Packs". Both | |
| terms are in use in the Mylex documentation; I have chosen to standardize on | |
| the more generic "Logical Drive" and "Drive Group". | |
| DAC960 RAID disk devices are named in the style of the obsolete Device File | |
| System (DEVFS). The device corresponding to Logical Drive D on Controller C | |
| is referred to as /dev/rd/cCdD, and the partitions are called /dev/rd/cCdDp1 | |
| through /dev/rd/cCdDp7. For example, partition 3 of Logical Drive 5 on | |
| Controller 2 is referred to as /dev/rd/c2d5p3. Note that unlike with SCSI | |
| disks the device names will not change in the event of a disk drive failure. | |
| The DAC960 driver is assigned major numbers 48 - 55 with one major number per | |
| controller. The 8 bits of minor number are divided into 5 bits for the Logical | |
| Drive and 3 bits for the partition. | |
| SUPPORTED DAC960/AcceleRAID/eXtremeRAID PCI RAID CONTROLLERS | |
| The following list comprises the supported DAC960, AcceleRAID, and eXtremeRAID | |
| PCI RAID Controllers as of the date of this document. It is recommended that | |
| anyone purchasing a Mylex PCI RAID Controller not in the following table | |
| contact the author beforehand to verify that it is or will be supported. | |
| eXtremeRAID 3000 | |
| 1 Wide Ultra-2/LVD SCSI channel | |
| 2 External Fibre FC-AL channels | |
| 233MHz StrongARM SA 110 Processor | |
| 64 Bit 33MHz PCI (backward compatible with 32 Bit PCI slots) | |
| 32MB/64MB ECC SDRAM Memory | |
| eXtremeRAID 2000 | |
| 4 Wide Ultra-160 LVD SCSI channels | |
| 233MHz StrongARM SA 110 Processor | |
| 64 Bit 33MHz PCI (backward compatible with 32 Bit PCI slots) | |
| 32MB/64MB ECC SDRAM Memory | |
| AcceleRAID 352 | |
| 2 Wide Ultra-160 LVD SCSI channels | |
| 100MHz Intel i960RN RISC Processor | |
| 64 Bit 33MHz PCI (backward compatible with 32 Bit PCI slots) | |
| 32MB/64MB ECC SDRAM Memory | |
| AcceleRAID 170 | |
| 1 Wide Ultra-160 LVD SCSI channel | |
| 100MHz Intel i960RM RISC Processor | |
| 16MB/32MB/64MB ECC SDRAM Memory | |
| AcceleRAID 160 (AcceleRAID 170LP) | |
| 1 Wide Ultra-160 LVD SCSI channel | |
| 100MHz Intel i960RS RISC Processor | |
| Built in 16M ECC SDRAM Memory | |
| PCI Low Profile Form Factor - fit for 2U height | |
| eXtremeRAID 1100 (DAC1164P) | |
| 3 Wide Ultra-2/LVD SCSI channels | |
| 233MHz StrongARM SA 110 Processor | |
| 64 Bit 33MHz PCI (backward compatible with 32 Bit PCI slots) | |
| 16MB/32MB/64MB Parity SDRAM Memory with Battery Backup | |
| AcceleRAID 250 (DAC960PTL1) | |
| Uses onboard Symbios SCSI chips on certain motherboards | |
| Also includes one onboard Wide Ultra-2/LVD SCSI Channel | |
| 66MHz Intel i960RD RISC Processor | |
| 4MB/8MB/16MB/32MB/64MB/128MB ECC EDO Memory | |
| AcceleRAID 200 (DAC960PTL0) | |
| Uses onboard Symbios SCSI chips on certain motherboards | |
| Includes no onboard SCSI Channels | |
| 66MHz Intel i960RD RISC Processor | |
| 4MB/8MB/16MB/32MB/64MB/128MB ECC EDO Memory | |
| AcceleRAID 150 (DAC960PRL) | |
| Uses onboard Symbios SCSI chips on certain motherboards | |
| Also includes one onboard Wide Ultra-2/LVD SCSI Channel | |
| 33MHz Intel i960RP RISC Processor | |
| 4MB Parity EDO Memory | |
| DAC960PJ 1/2/3 Wide Ultra SCSI-3 Channels | |
| 66MHz Intel i960RD RISC Processor | |
| 4MB/8MB/16MB/32MB/64MB/128MB ECC EDO Memory | |
| DAC960PG 1/2/3 Wide Ultra SCSI-3 Channels | |
| 33MHz Intel i960RP RISC Processor | |
| 4MB/8MB ECC EDO Memory | |
| DAC960PU 1/2/3 Wide Ultra SCSI-3 Channels | |
| Intel i960CF RISC Processor | |
| 4MB/8MB EDRAM or 2MB/4MB/8MB/16MB/32MB DRAM Memory | |
| DAC960PD 1/2/3 Wide Fast SCSI-2 Channels | |
| Intel i960CF RISC Processor | |
| 4MB/8MB EDRAM or 2MB/4MB/8MB/16MB/32MB DRAM Memory | |
| DAC960PL 1/2/3 Wide Fast SCSI-2 Channels | |
| Intel i960 RISC Processor | |
| 2MB/4MB/8MB/16MB/32MB DRAM Memory | |
| DAC960P 1/2/3 Wide Fast SCSI-2 Channels | |
| Intel i960 RISC Processor | |
| 2MB/4MB/8MB/16MB/32MB DRAM Memory | |
| For the eXtremeRAID 2000/3000 and AcceleRAID 352/170/160, firmware version | |
| 6.00-01 or above is required. | |
| For the eXtremeRAID 1100, firmware version 5.06-0-52 or above is required. | |
| For the AcceleRAID 250, 200, and 150, firmware version 4.06-0-57 or above is | |
| required. | |
| For the DAC960PJ and DAC960PG, firmware version 4.06-0-00 or above is required. | |
| For the DAC960PU, DAC960PD, DAC960PL, and DAC960P, either firmware version | |
| 3.51-0-04 or above is required (for dual Flash ROM controllers), or firmware | |
| version 2.73-0-00 or above is required (for single Flash ROM controllers) | |
| Please note that not all SCSI disk drives are suitable for use with DAC960 | |
| controllers, and only particular firmware versions of any given model may | |
| actually function correctly. Similarly, not all motherboards have a BIOS that | |
| properly initializes the AcceleRAID 250, AcceleRAID 200, AcceleRAID 150, | |
| DAC960PJ, and DAC960PG because the Intel i960RD/RP is a multi-function device. | |
| If in doubt, contact Mylex RAID Technical Support (mylexsup@us.ibm.com) to | |
| verify compatibility. Mylex makes available a hard disk compatibility list at | |
| http://www.mylex.com/support/hdcomp/hd-lists.html. | |
| DRIVER INSTALLATION | |
| This distribution was prepared for Linux kernel version 2.2.19 or 2.4.12. | |
| To install the DAC960 RAID driver, you may use the following commands, | |
| replacing "/usr/src" with wherever you keep your Linux kernel source tree: | |
| cd /usr/src | |
| tar -xvzf DAC960-2.2.11.tar.gz (or DAC960-2.4.11.tar.gz) | |
| mv README.DAC960 linux/Documentation | |
| mv DAC960.[ch] linux/drivers/block | |
| patch -p0 < DAC960.patch (if DAC960.patch is included) | |
| cd linux | |
| make config | |
| make bzImage (or zImage) | |
| Then install "arch/x86/boot/bzImage" or "arch/x86/boot/zImage" as your | |
| standard kernel, run lilo if appropriate, and reboot. | |
| To create the necessary devices in /dev, the "make_rd" script included in | |
| "DAC960-Utilities.tar.gz" from http://www.dandelion.com/Linux/ may be used. | |
| LILO 21 and FDISK v2.9 include DAC960 support; also included in this archive | |
| are patches to LILO 20 and FDISK v2.8 that add DAC960 support, along with | |
| statically linked executables of LILO and FDISK. This modified version of LILO | |
| will allow booting from a DAC960 controller and/or mounting the root file | |
| system from a DAC960. | |
| Red Hat Linux 6.0 and SuSE Linux 6.1 include support for Mylex PCI RAID | |
| controllers. Installing directly onto a DAC960 may be problematic from other | |
| Linux distributions until their installation utilities are updated. | |
| INSTALLATION NOTES | |
| Before installing Linux or adding DAC960 logical drives to an existing Linux | |
| system, the controller must first be configured to provide one or more logical | |
| drives using the BIOS Configuration Utility or DACCF. Please note that since | |
| there are only at most 6 usable partitions on each logical drive, systems | |
| requiring more partitions should subdivide a drive group into multiple logical | |
| drives, each of which can have up to 6 usable partitions. Also, note that with | |
| large disk arrays it is advisable to enable the 8GB BIOS Geometry (255/63) | |
| rather than accepting the default 2GB BIOS Geometry (128/32); failing to so do | |
| will cause the logical drive geometry to have more than 65535 cylinders which | |
| will make it impossible for FDISK to be used properly. The 8GB BIOS Geometry | |
| can be enabled by configuring the DAC960 BIOS, which is accessible via Alt-M | |
| during the BIOS initialization sequence. | |
| For maximum performance and the most efficient E2FSCK performance, it is | |
| recommended that EXT2 file systems be built with a 4KB block size and 16 block | |
| stride to match the DAC960 controller's 64KB default stripe size. The command | |
| "mke2fs -b 4096 -R stride=16 <device>" is appropriate. Unless there will be a | |
| large number of small files on the file systems, it is also beneficial to add | |
| the "-i 16384" option to increase the bytes per inode parameter thereby | |
| reducing the file system metadata. Finally, on systems that will only be run | |
| with Linux 2.2 or later kernels it is beneficial to enable sparse superblocks | |
| with the "-s 1" option. | |
| DAC960 ANNOUNCEMENTS MAILING LIST | |
| The DAC960 Announcements Mailing List provides a forum for informing Linux | |
| users of new driver releases and other announcements regarding Linux support | |
| for DAC960 PCI RAID Controllers. To join the mailing list, send a message to | |
| "dac960-announce-request@dandelion.com" with the line "subscribe" in the | |
| message body. | |
| CONTROLLER CONFIGURATION AND STATUS MONITORING | |
| The DAC960 RAID controllers running firmware 4.06 or above include a Background | |
| Initialization facility so that system downtime is minimized both for initial | |
| installation and subsequent configuration of additional storage. The BIOS | |
| Configuration Utility (accessible via Alt-R during the BIOS initialization | |
| sequence) is used to quickly configure the controller, and then the logical | |
| drives that have been created are available for immediate use even while they | |
| are still being initialized by the controller. The primary need for online | |
| configuration and status monitoring is then to avoid system downtime when disk | |
| drives fail and must be replaced. Mylex's online monitoring and configuration | |
| utilities are being ported to Linux and will become available at some point in | |
| the future. Note that with a SAF-TE (SCSI Accessed Fault-Tolerant Enclosure) | |
| enclosure, the controller is able to rebuild failed drives automatically as | |
| soon as a drive replacement is made available. | |
| The primary interfaces for controller configuration and status monitoring are | |
| special files created in the /proc/rd/... hierarchy along with the normal | |
| system console logging mechanism. Whenever the system is operating, the DAC960 | |
| driver queries each controller for status information every 10 seconds, and | |
| checks for additional conditions every 60 seconds. The initial status of each | |
| controller is always available for controller N in /proc/rd/cN/initial_status, | |
| and the current status as of the last status monitoring query is available in | |
| /proc/rd/cN/current_status. In addition, status changes are also logged by the | |
| driver to the system console and will appear in the log files maintained by | |
| syslog. The progress of asynchronous rebuild or consistency check operations | |
| is also available in /proc/rd/cN/current_status, and progress messages are | |
| logged to the system console at most every 60 seconds. | |
| Starting with the 2.2.3/2.0.3 versions of the driver, the status information | |
| available in /proc/rd/cN/initial_status and /proc/rd/cN/current_status has been | |
| augmented to include the vendor, model, revision, and serial number (if | |
| available) for each physical device found connected to the controller: | |
| ***** DAC960 RAID Driver Version 2.2.3 of 19 August 1999 ***** | |
| Copyright 1998-1999 by Leonard N. Zubkoff <lnz@dandelion.com> | |
| Configuring Mylex DAC960PRL PCI RAID Controller | |
| Firmware Version: 4.07-0-07, Channels: 1, Memory Size: 16MB | |
| PCI Bus: 1, Device: 4, Function: 1, I/O Address: Unassigned | |
| PCI Address: 0xFE300000 mapped at 0xA0800000, IRQ Channel: 21 | |
| Controller Queue Depth: 128, Maximum Blocks per Command: 128 | |
| Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33 | |
| Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63 | |
| SAF-TE Enclosure Management Enabled | |
| Physical Devices: | |
| 0:0 Vendor: IBM Model: DRVS09D Revision: 0270 | |
| Serial Number: 68016775HA | |
| Disk Status: Online, 17928192 blocks | |
| 0:1 Vendor: IBM Model: DRVS09D Revision: 0270 | |
| Serial Number: 68004E53HA | |
| Disk Status: Online, 17928192 blocks | |
| 0:2 Vendor: IBM Model: DRVS09D Revision: 0270 | |
| Serial Number: 13013935HA | |
| Disk Status: Online, 17928192 blocks | |
| 0:3 Vendor: IBM Model: DRVS09D Revision: 0270 | |
| Serial Number: 13016897HA | |
| Disk Status: Online, 17928192 blocks | |
| 0:4 Vendor: IBM Model: DRVS09D Revision: 0270 | |
| Serial Number: 68019905HA | |
| Disk Status: Online, 17928192 blocks | |
| 0:5 Vendor: IBM Model: DRVS09D Revision: 0270 | |
| Serial Number: 68012753HA | |
| Disk Status: Online, 17928192 blocks | |
| 0:6 Vendor: ESG-SHV Model: SCA HSBP M6 Revision: 0.61 | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Online, 89640960 blocks, Write Thru | |
| No Rebuild or Consistency Check in Progress | |
| To simplify the monitoring process for custom software, the special file | |
| /proc/rd/status returns "OK" when all DAC960 controllers in the system are | |
| operating normally and no failures have occurred, or "ALERT" if any logical | |
| drives are offline or critical or any non-standby physical drives are dead. | |
| Configuration commands for controller N are available via the special file | |
| /proc/rd/cN/user_command. A human readable command can be written to this | |
| special file to initiate a configuration operation, and the results of the | |
| operation can then be read back from the special file in addition to being | |
| logged to the system console. The shell command sequence | |
| echo "<configuration-command>" > /proc/rd/c0/user_command | |
| cat /proc/rd/c0/user_command | |
| is typically used to execute configuration commands. The configuration | |
| commands are: | |
| flush-cache | |
| The "flush-cache" command flushes the controller's cache. The system | |
| automatically flushes the cache at shutdown or if the driver module is | |
| unloaded, so this command is only needed to be certain a write back cache | |
| is flushed to disk before the system is powered off by a command to a UPS. | |
| Note that the flush-cache command also stops an asynchronous rebuild or | |
| consistency check, so it should not be used except when the system is being | |
| halted. | |
| kill <channel>:<target-id> | |
| The "kill" command marks the physical drive <channel>:<target-id> as DEAD. | |
| This command is provided primarily for testing, and should not be used | |
| during normal system operation. | |
| make-online <channel>:<target-id> | |
| The "make-online" command changes the physical drive <channel>:<target-id> | |
| from status DEAD to status ONLINE. In cases where multiple physical drives | |
| have been killed simultaneously, this command may be used to bring all but | |
| one of them back online, after which a rebuild to the final drive is | |
| necessary. | |
| Warning: make-online should only be used on a dead physical drive that is | |
| an active part of a drive group, never on a standby drive. The command | |
| should never be used on a dead drive that is part of a critical logical | |
| drive; rebuild should be used if only a single drive is dead. | |
| make-standby <channel>:<target-id> | |
| The "make-standby" command changes physical drive <channel>:<target-id> | |
| from status DEAD to status STANDBY. It should only be used in cases where | |
| a dead drive was replaced after an automatic rebuild was performed onto a | |
| standby drive. It cannot be used to add a standby drive to the controller | |
| configuration if one was not created initially; the BIOS Configuration | |
| Utility must be used for that currently. | |
| rebuild <channel>:<target-id> | |
| The "rebuild" command initiates an asynchronous rebuild onto physical drive | |
| <channel>:<target-id>. It should only be used when a dead drive has been | |
| replaced. | |
| check-consistency <logical-drive-number> | |
| The "check-consistency" command initiates an asynchronous consistency check | |
| of <logical-drive-number> with automatic restoration. It can be used | |
| whenever it is desired to verify the consistency of the redundancy | |
| information. | |
| cancel-rebuild | |
| cancel-consistency-check | |
| The "cancel-rebuild" and "cancel-consistency-check" commands cancel any | |
| rebuild or consistency check operations previously initiated. | |
| EXAMPLE I - DRIVE FAILURE WITHOUT A STANDBY DRIVE | |
| The following annotated logs demonstrate the controller configuration and and | |
| online status monitoring capabilities of the Linux DAC960 Driver. The test | |
| configuration comprises 6 1GB Quantum Atlas I disk drives on two channels of a | |
| DAC960PJ controller. The physical drives are configured into a single drive | |
| group without a standby drive, and the drive group has been configured into two | |
| logical drives, one RAID-5 and one RAID-6. Note that these logs are from an | |
| earlier version of the driver and the messages have changed somewhat with newer | |
| releases, but the functionality remains similar. First, here is the current | |
| status of the RAID configuration: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ***** DAC960 RAID Driver Version 2.0.0 of 23 March 1999 ***** | |
| Copyright 1998-1999 by Leonard N. Zubkoff <lnz@dandelion.com> | |
| Configuring Mylex DAC960PJ PCI RAID Controller | |
| Firmware Version: 4.06-0-08, Channels: 3, Memory Size: 8MB | |
| PCI Bus: 0, Device: 19, Function: 1, I/O Address: Unassigned | |
| PCI Address: 0xFD4FC000 mapped at 0x8807000, IRQ Channel: 9 | |
| Controller Queue Depth: 128, Maximum Blocks per Command: 128 | |
| Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33 | |
| Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63 | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Online, 2201600 blocks | |
| 1:2 - Disk: Online, 2201600 blocks | |
| 1:3 - Disk: Online, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Online, 5498880 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Online, 3305472 blocks, Write Thru | |
| No Rebuild or Consistency Check in Progress | |
| gwynedd:/u/lnz# cat /proc/rd/status | |
| OK | |
| The above messages indicate that everything is healthy, and /proc/rd/status | |
| returns "OK" indicating that there are no problems with any DAC960 controller | |
| in the system. For demonstration purposes, while I/O is active Physical Drive | |
| 1:1 is now disconnected, simulating a drive failure. The failure is noted by | |
| the driver within 10 seconds of the controller's having detected it, and the | |
| driver logs the following console status messages indicating that Logical | |
| Drives 0 and 1 are now CRITICAL as a result of Physical Drive 1:1 being DEAD: | |
| DAC960#0: Physical Drive 1:2 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02 | |
| DAC960#0: Physical Drive 1:3 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02 | |
| DAC960#0: Physical Drive 1:1 killed because of timeout on SCSI command | |
| DAC960#0: Physical Drive 1:1 is now DEAD | |
| DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now CRITICAL | |
| DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now CRITICAL | |
| The Sense Keys logged here are just Check Condition / Unit Attention conditions | |
| arising from a SCSI bus reset that is forced by the controller during its error | |
| recovery procedures. Concurrently with the above, the driver status available | |
| from /proc/rd also reflects the drive failure. The status message in | |
| /proc/rd/status has changed from "OK" to "ALERT": | |
| gwynedd:/u/lnz# cat /proc/rd/status | |
| ALERT | |
| and /proc/rd/c0/current_status has been updated: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ... | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Dead, 2201600 blocks | |
| 1:2 - Disk: Online, 2201600 blocks | |
| 1:3 - Disk: Online, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Critical, 5498880 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Critical, 3305472 blocks, Write Thru | |
| No Rebuild or Consistency Check in Progress | |
| Since there are no standby drives configured, the system can continue to access | |
| the logical drives in a performance degraded mode until the failed drive is | |
| replaced and a rebuild operation completed to restore the redundancy of the | |
| logical drives. Once Physical Drive 1:1 is replaced with a properly | |
| functioning drive, or if the physical drive was killed without having failed | |
| (e.g., due to electrical problems on the SCSI bus), the user can instruct the | |
| controller to initiate a rebuild operation onto the newly replaced drive: | |
| gwynedd:/u/lnz# echo "rebuild 1:1" > /proc/rd/c0/user_command | |
| gwynedd:/u/lnz# cat /proc/rd/c0/user_command | |
| Rebuild of Physical Drive 1:1 Initiated | |
| The echo command instructs the controller to initiate an asynchronous rebuild | |
| operation onto Physical Drive 1:1, and the status message that results from the | |
| operation is then available for reading from /proc/rd/c0/user_command, as well | |
| as being logged to the console by the driver. | |
| Within 10 seconds of this command the driver logs the initiation of the | |
| asynchronous rebuild operation: | |
| DAC960#0: Rebuild of Physical Drive 1:1 Initiated | |
| DAC960#0: Physical Drive 1:1 Error Log: Sense Key = 6, ASC = 29, ASCQ = 01 | |
| DAC960#0: Physical Drive 1:1 is now WRITE-ONLY | |
| DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 1% completed | |
| and /proc/rd/c0/current_status is updated: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ... | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Write-Only, 2201600 blocks | |
| 1:2 - Disk: Online, 2201600 blocks | |
| 1:3 - Disk: Online, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Critical, 5498880 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Critical, 3305472 blocks, Write Thru | |
| Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 6% completed | |
| As the rebuild progresses, the current status in /proc/rd/c0/current_status is | |
| updated every 10 seconds: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ... | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Write-Only, 2201600 blocks | |
| 1:2 - Disk: Online, 2201600 blocks | |
| 1:3 - Disk: Online, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Critical, 5498880 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Critical, 3305472 blocks, Write Thru | |
| Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 15% completed | |
| and every minute a progress message is logged to the console by the driver: | |
| DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 32% completed | |
| DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 63% completed | |
| DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 94% completed | |
| DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 94% completed | |
| Finally, the rebuild completes successfully. The driver logs the status of the | |
| logical and physical drives and the rebuild completion: | |
| DAC960#0: Rebuild Completed Successfully | |
| DAC960#0: Physical Drive 1:1 is now ONLINE | |
| DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now ONLINE | |
| DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now ONLINE | |
| /proc/rd/c0/current_status is updated: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ... | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Online, 2201600 blocks | |
| 1:2 - Disk: Online, 2201600 blocks | |
| 1:3 - Disk: Online, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Online, 5498880 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Online, 3305472 blocks, Write Thru | |
| Rebuild Completed Successfully | |
| and /proc/rd/status indicates that everything is healthy once again: | |
| gwynedd:/u/lnz# cat /proc/rd/status | |
| OK | |
| EXAMPLE II - DRIVE FAILURE WITH A STANDBY DRIVE | |
| The following annotated logs demonstrate the controller configuration and and | |
| online status monitoring capabilities of the Linux DAC960 Driver. The test | |
| configuration comprises 6 1GB Quantum Atlas I disk drives on two channels of a | |
| DAC960PJ controller. The physical drives are configured into a single drive | |
| group with a standby drive, and the drive group has been configured into two | |
| logical drives, one RAID-5 and one RAID-6. Note that these logs are from an | |
| earlier version of the driver and the messages have changed somewhat with newer | |
| releases, but the functionality remains similar. First, here is the current | |
| status of the RAID configuration: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ***** DAC960 RAID Driver Version 2.0.0 of 23 March 1999 ***** | |
| Copyright 1998-1999 by Leonard N. Zubkoff <lnz@dandelion.com> | |
| Configuring Mylex DAC960PJ PCI RAID Controller | |
| Firmware Version: 4.06-0-08, Channels: 3, Memory Size: 8MB | |
| PCI Bus: 0, Device: 19, Function: 1, I/O Address: Unassigned | |
| PCI Address: 0xFD4FC000 mapped at 0x8807000, IRQ Channel: 9 | |
| Controller Queue Depth: 128, Maximum Blocks per Command: 128 | |
| Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33 | |
| Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63 | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Online, 2201600 blocks | |
| 1:2 - Disk: Online, 2201600 blocks | |
| 1:3 - Disk: Standby, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru | |
| No Rebuild or Consistency Check in Progress | |
| gwynedd:/u/lnz# cat /proc/rd/status | |
| OK | |
| The above messages indicate that everything is healthy, and /proc/rd/status | |
| returns "OK" indicating that there are no problems with any DAC960 controller | |
| in the system. For demonstration purposes, while I/O is active Physical Drive | |
| 1:2 is now disconnected, simulating a drive failure. The failure is noted by | |
| the driver within 10 seconds of the controller's having detected it, and the | |
| driver logs the following console status messages: | |
| DAC960#0: Physical Drive 1:1 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02 | |
| DAC960#0: Physical Drive 1:3 Error Log: Sense Key = 6, ASC = 29, ASCQ = 02 | |
| DAC960#0: Physical Drive 1:2 killed because of timeout on SCSI command | |
| DAC960#0: Physical Drive 1:2 is now DEAD | |
| DAC960#0: Physical Drive 1:2 killed because it was removed | |
| DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now CRITICAL | |
| DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now CRITICAL | |
| Since a standby drive is configured, the controller automatically begins | |
| rebuilding onto the standby drive: | |
| DAC960#0: Physical Drive 1:3 is now WRITE-ONLY | |
| DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 4% completed | |
| Concurrently with the above, the driver status available from /proc/rd also | |
| reflects the drive failure and automatic rebuild. The status message in | |
| /proc/rd/status has changed from "OK" to "ALERT": | |
| gwynedd:/u/lnz# cat /proc/rd/status | |
| ALERT | |
| and /proc/rd/c0/current_status has been updated: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ... | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Online, 2201600 blocks | |
| 1:2 - Disk: Dead, 2201600 blocks | |
| 1:3 - Disk: Write-Only, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Critical, 4399104 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Critical, 2754560 blocks, Write Thru | |
| Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 4% completed | |
| As the rebuild progresses, the current status in /proc/rd/c0/current_status is | |
| updated every 10 seconds: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ... | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Online, 2201600 blocks | |
| 1:2 - Disk: Dead, 2201600 blocks | |
| 1:3 - Disk: Write-Only, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Critical, 4399104 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Critical, 2754560 blocks, Write Thru | |
| Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 40% completed | |
| and every minute a progress message is logged on the console by the driver: | |
| DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 40% completed | |
| DAC960#0: Rebuild in Progress: Logical Drive 0 (/dev/rd/c0d0) 76% completed | |
| DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 66% completed | |
| DAC960#0: Rebuild in Progress: Logical Drive 1 (/dev/rd/c0d1) 84% completed | |
| Finally, the rebuild completes successfully. The driver logs the status of the | |
| logical and physical drives and the rebuild completion: | |
| DAC960#0: Rebuild Completed Successfully | |
| DAC960#0: Physical Drive 1:3 is now ONLINE | |
| DAC960#0: Logical Drive 0 (/dev/rd/c0d0) is now ONLINE | |
| DAC960#0: Logical Drive 1 (/dev/rd/c0d1) is now ONLINE | |
| /proc/rd/c0/current_status is updated: | |
| ***** DAC960 RAID Driver Version 2.0.0 of 23 March 1999 ***** | |
| Copyright 1998-1999 by Leonard N. Zubkoff <lnz@dandelion.com> | |
| Configuring Mylex DAC960PJ PCI RAID Controller | |
| Firmware Version: 4.06-0-08, Channels: 3, Memory Size: 8MB | |
| PCI Bus: 0, Device: 19, Function: 1, I/O Address: Unassigned | |
| PCI Address: 0xFD4FC000 mapped at 0x8807000, IRQ Channel: 9 | |
| Controller Queue Depth: 128, Maximum Blocks per Command: 128 | |
| Driver Queue Depth: 127, Maximum Scatter/Gather Segments: 33 | |
| Stripe Size: 64KB, Segment Size: 8KB, BIOS Geometry: 255/63 | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Online, 2201600 blocks | |
| 1:2 - Disk: Dead, 2201600 blocks | |
| 1:3 - Disk: Online, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru | |
| Rebuild Completed Successfully | |
| and /proc/rd/status indicates that everything is healthy once again: | |
| gwynedd:/u/lnz# cat /proc/rd/status | |
| OK | |
| Note that the absence of a viable standby drive does not create an "ALERT" | |
| status. Once dead Physical Drive 1:2 has been replaced, the controller must be | |
| told that this has occurred and that the newly replaced drive should become the | |
| new standby drive: | |
| gwynedd:/u/lnz# echo "make-standby 1:2" > /proc/rd/c0/user_command | |
| gwynedd:/u/lnz# cat /proc/rd/c0/user_command | |
| Make Standby of Physical Drive 1:2 Succeeded | |
| The echo command instructs the controller to make Physical Drive 1:2 into a | |
| standby drive, and the status message that results from the operation is then | |
| available for reading from /proc/rd/c0/user_command, as well as being logged to | |
| the console by the driver. Within 60 seconds of this command the driver logs: | |
| DAC960#0: Physical Drive 1:2 Error Log: Sense Key = 6, ASC = 29, ASCQ = 01 | |
| DAC960#0: Physical Drive 1:2 is now STANDBY | |
| DAC960#0: Make Standby of Physical Drive 1:2 Succeeded | |
| and /proc/rd/c0/current_status is updated: | |
| gwynedd:/u/lnz# cat /proc/rd/c0/current_status | |
| ... | |
| Physical Devices: | |
| 0:1 - Disk: Online, 2201600 blocks | |
| 0:2 - Disk: Online, 2201600 blocks | |
| 0:3 - Disk: Online, 2201600 blocks | |
| 1:1 - Disk: Online, 2201600 blocks | |
| 1:2 - Disk: Standby, 2201600 blocks | |
| 1:3 - Disk: Online, 2201600 blocks | |
| Logical Drives: | |
| /dev/rd/c0d0: RAID-5, Online, 4399104 blocks, Write Thru | |
| /dev/rd/c0d1: RAID-6, Online, 2754560 blocks, Write Thru | |
| Rebuild Completed Successfully |