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diff --git a/Documentation/blockdev/README.DAC960 b/Documentation/blockdev/README.DAC960 new file mode 100644 index 00000000000..0e8f618ab53 --- /dev/null +++ b/Documentation/blockdev/README.DAC960 @@ -0,0 +1,756 @@ + 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/i386/boot/bzImage" or "arch/i386/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 |