| 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 |