mirror of https://github.com/tLDP/LDP
567 lines
21 KiB
Plaintext
567 lines
21 KiB
Plaintext
<!doctype linuxdoc system>
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<article>
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<title> Linux DPT Hardware RAID HOWTO </title>
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<author>Ram Samudrala <tt>(me@ram.org)</tt> </author>
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<date> v1.62, August 4, 2004 </date>
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<abstract>
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How to set up hardware RAID under Linux. This HOWTO is now limited to
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making small changes from version 1.6.
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</abstract>
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<!-- ************************************************************* -->
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<toc>
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<sect> Introduction
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<p> This document describes how to set up SCSI hardware RAID, focusing
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mainly on host-based adapters from DPT, though the principles applied
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here are fairly general. </p>
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<p> Use the information below at your own risk. I disclaim all
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responsibility for anything you may do after reading this HOWTO. The
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latest version of this HOWTO will always be available at <htmlurl
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url="http://www.ram.org/computing/linux/dpt_raid.html"
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name="http://www.ram.org/computing/linux/dpt_raid.html">. </p>
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<p> For the purposes of this HOWTO, I am assuming you have only a
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Linux system running. Also, note that I've only tried this out with
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the DPT Smartcache IV PM2144UW and PM3334UW controllers, with DPT
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(SmartRAID tower) and Wetex enclosures, and I have no experience with
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other setups. So things may be different for your setup. </p>
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</sect>
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<!-- ************************************************************* -->
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<sect> Supported controllers
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<!-- ************************************************************* -->
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<p> One well-supported host-based hardware RAID controller (i.e, a
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controller for which there exists a driver under Linux) is one that is
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made by <url url="http://www.dpt.com" name="DPT">. However, there
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exist other host-based and SCSI-to-SCSI controllers which may work
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under Linux. These include the ones made by <url
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url="http://www.syred.com" name="Syred">, <url
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url="http://www.icp-vortex.com" name="ICP-Vortex">, and <url
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url="http://www.mylex.com" name="BusLogic">. See the <url
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url="http://linas.org/linux/raid.html" name="RAID solutions for Linux
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page"> for more info. </p>
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<p> If, in the future, there is support for other controllers, I will
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do my best to incorporate that information into this HOWTO. Please
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send me any such information you think is appropriate for this
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HOWTO. </p>
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<!-- ************************************************************* -->
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<sect1> DPT controllers
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<p> This document is currently DPT-oriented. Essentially all the
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SmartRAID IV controllers are supported. </p>
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</sect1>
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<!-- ************************************************************* -->
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<sect1> ICP vortex controllers
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<p> ICP vortex has a complete line of disk array controllers which
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support Linux. The ICP driver is in the Linux kernel since version
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2.0.31. All major Linux Distributors S.u.S.e., LST Power Linux, Caldera
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and Red Hat support the ICP controllers as boot/installation
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controllers. The RAID system can easily be configured with their
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ROMSETUP (you do not have to boot MS-DOS for configuration!). </p>
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<p> With the monitoring utility GDTMON it is possible to manage the
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complete ICP RAID system during operation (check transfer rates, set
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parameters for the controller and hard disks, exchange defective hard
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disks, etc.). Currently available are: 1 and 2 channel wide and ultra
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SCSI controller for RAID 0 and RAID 1 1, 2, 3 and 5 chn. wide and
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ultra SCSI controller for RAID 0, 1, 4, 5 and 10 1 and 2 channel wide
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and ultra2 LVDS SCSI controller for RAID 0 and RAID 1 1, 2, 3 and 5
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chn. wide and ultra2 LVDS SCSI controller for RAID 0, 1, 4, 5 and 10 1
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and 2 port Fibre Channel controllers for RAID 0, 1, 4, 5 and 10 Pretty
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soon there will be also 64-bit controllers available. </p>
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<p> ICP is transitioning the entry-level RS series from Ultra2 SCSI to
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Ultra160 SCSI. The drivers, firmware, features, capabilities etc
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remain the same. They are still 32 Bit cards with the i960RS
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processor working at 100MHz. The only difference is they will work at
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Ultra160 (data transfer rate of 160MB/sec) rather than Ultra2 (data
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transfer of 80MB/sec). </p>
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<p> Effective immediately, the GDT7523RN units will become GDT8523RZ
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and the GDT7623RN units will become GDT8623RZ. The transition from
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33MHz on the PCI bus to 66MHz represents a huge potential performance
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increase. The new cards will have the new Intel 80303 "Zion"
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processor, allowing bus master transfer rates of up to 528MB/sec, and
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will take up to 256MB of ECC RAM on PC133 SDRAM Dimms. </p>
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</sect1>
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<!-- ************************************************************* -->
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</sect>
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<!-- ************************************************************* -->
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<sect> What hardware should be used?
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<!-- ************************************************************* -->
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<sect1> Controller type
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<p> Given all these options, if you're looking for a RAID solution,
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you need to think carefully about what you want. Depending on what
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you want to do, and which RAID level you wish to use, some cards may
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be better than others. SCSI-to-SCSI adapters may not be as good as
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host-based adapters, for example. Michael Neuffer (<htmlurl
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url="mailto:neuffer@uni-mainz.de"
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name="neuffer@uni-mainz.de">), the author of the EATA-DMA
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driver, has a nice discussion about this on his <url
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url="http://www.uni-mainz.de/~neuffer/scsi/" name="Linux High
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Performance SCSI and RAID page">. </p>
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</sect1>
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<sect1> Enclosure type
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<p> The enclosure type affects the hot swap-ability of the drive, the
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warning systems (i.e., whether there will be indication of failure,
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and whether you will know which drive has failed), and what kind of
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treatment your drive receives (for example, redundant cooling and
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power supplies). We used the DPT supplied enclosures which work
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extremely well, but they are expensive. </p>
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</sect1>
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</sect>
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<sect> Installation
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<sect1> Installing and configuring the hardware
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<p> Refer to the instruction manual to install the card and the
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drives. For DPT, since a storage manager for Linux doesn't exist yet,
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you need to create a MS-DOS-formatted disk with the system on it
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(usually created using the command "format /s" at the MS-DOS prompt).
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You will also be using the DPT storage manager for MS-DOS (available
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from <url url="http://www.adaptec.com" name="the Adaptec website">),
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which you should probably make a copy of for safety. </p>
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<p> Once the hardware is in place, boot using the DOS system
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disk. Replace the DOS disk with the storage manager. And invoke the
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storage manager using the command:
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<tscreen><verb>
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a:\ dptmgr
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</verb></tscreen>
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Wait a minute or so, and you'll get a nice menu of options. Configure
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the set of disks as a hardware RAID (single logical array). Choose
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"other" as the operating system. </p>
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<p> The MS-DOS storage manager is a lot easier to use with a mouse,
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and so you might want to have a mouse driver on the initial system
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disk you create. </p>
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<p> Technically, it should be possible to run the SCO storage manager
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under Linux, but it may be more trouble than its worth. It's probably
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more easier to run the MS-DOS storage manager under Linux. </p>
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</sect1>
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<sect1> Configuring the kernel
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<p> You will need to configure the kernel with SCSI support and the
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appropriate low level driver. See the <url
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url="http://sunsite.unc.edu/mdw/HOWTO/Kernel-HOWTO.html" name="Kernel
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HOWTO"> for information on how to compile the kernel. Once you choose
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"yes" for SCSI support, in the low level drivers section, select the
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driver of your choice (EATA DMA or EATA ISA/EISA/PCI for most EATA DMA
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compliant (DPT) cards, EATA PIO for the very old PM2001 and PM2012A
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from DPT). Most drivers, including the EATA DMA and EATA ISA/EISA/PCI
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drivers, should be available in recent kernel versions. </p>
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<p> Once you have the kernel compiled, reboot, and if you've set up
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everything correctly, you should see the driver recognising the RAID
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as a single SCSI disk. If you use RAID-5, you will see the size of
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this disk to be 2/3 of the actual disk space available. </p>
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</sect1>
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<sect1> Bootup messages
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<p> The messages you see upon bootup if you're using the EATA DMA
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driver should look something like this:
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<tscreen><verb>
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EATA (Extended Attachment) driver version: 2.59b
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developed in co-operation with DPT
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(c) 1993-96 Michael Neuffer, mike@i-Connect.Net
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Registered HBAs:
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HBA no. Boardtype Revis EATA Bus BaseIO IRQ DMA Ch ID Pr QS S/G IS
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scsi0 : PM2144UW v07L.Y 2.0c PCI 0xef90 11 BMST 1 7 N 64 252 Y
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scsi0 : EATA (Extended Attachment) HBA driver
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scsi : 1 host.
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Vendor: DPT Model: RAID-5 Rev: 07LY
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Type: Direct-Access ANSI SCSI revision: 02
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Detected scsi disk sda at scsi0, channel 0, id 8, lun 0
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scsi0: queue depth for target 8 on channel 0 set to 64
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scsi : detected 1 SCSI disk total.
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SCSI device sda: hdwr sector= 512 bytes. Sectors= 35591040 [17378 MB] [17.4 GB]
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</verb></tscreen>
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(The above display is for a setup with a single DPT SCSI controller,
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configured as RAID-5, with three disks of 9 GB each.) </p>
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<p> The messages you see upon bootup if you're using the EATA
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ISA/EISA/PCI driver should look something like this:
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<tscreen><verb>
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aic7xxx: <Adaptec AHA-294X SCSI host adapter> at PCI 15
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aic7xxx: BIOS enabled, IO Port 0x7000, IO Mem 0x3100000, IRQ 15, Revision B
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aic7xxx: Single Channel, SCSI ID 7, 16/16 SCBs, QFull 16, QMask 0x1f
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EATA0: address 0x7010 in use, skipping probe.
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EATA0: 2.0C, PCI 0x7410, IRQ 11, BMST, SG 252, MB 64, tc:y, lc:y, mq:62.
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EATA0: wide SCSI support enabled, max_id 16, max_lun 8.
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EATA0: SCSI channel 0 enabled, host target ID 6.
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EATA/DMA 2.0x: Copyright (C) 1994-1997 Dario Ballabio.
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scsi0 : Adaptec AHA274x/284x/294x (EISA/VLB/PCI-Fast SCSI) 4.1.1/3.2.1
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scsi1 : EATA/DMA 2.0x rev. 3.11.00
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scsi : 2 hosts.
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scsi0: Scanning channel A for devices.
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Vendor: IBM OEM Model: DFHSS2F Rev: 1818
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Type: Direct-Access ANSI SCSI revision: 02
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Detected scsi disk sda at scsi0, channel 0, id 0, lun 0
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Vendor: SEAGATE Model: ST41650 TX Rev: DG01
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Type: Direct-Access ANSI SCSI revision: 02
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Detected scsi disk sdb at scsi1, channel 0, id 0, lun 0
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Vendor: TEAC Model: FC-1 GF 00 Rev: RV L
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Type: Direct-Access ANSI SCSI revision: 01 CCS
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Detected scsi removable disk sdc at scsi1, channel 0, id 3, lun 0
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Vendor: SONY Model: CD-ROM CDU-541 Rev: 2.6a
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Type: CD-ROM ANSI SCSI revision: 02
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Detected scsi CD-ROM sr0 at scsi1, channel 0, id 5, lun 0
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EATA0: scsi1, channel 0, id 0, lun 0, cmds/lun 21, sorted, tagged.
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EATA0: scsi1, channel 0, id 3, lun 0, cmds/lun 21, sorted.
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EATA0: scsi1, channel 0, id 5, lun 0, cmds/lun 21, sorted.
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scsi : detected 1 SCSI cdrom 3 SCSI disks total.
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SCSI device sda: hdwr sector= 512 bytes. Sectors= 4404489 [2150 MB] [2.2 GB]
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SCSI device sdb: hdwr sector= 512 bytes. Sectors= 2779518 [1357 MB] [1.4 GB]
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SCSI device sdc: hdwr sector= 256 bytes. Sectors= 4160 [1 MB] [0.0 GB]
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</verb></tscreen>
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(The above display is for a setup with two SCSI controllers, DPT
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PM3224W and and Adaptec AHA2940.) </p>
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</sect1>
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</sect>
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<sect> Usage
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<sect1> fdisk, mke2fs, mount, etc.
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<p> You can now start treating the RAID as a regular disk. The first
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thing you'll need to do is partition the disk (using fdisk). You'll
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then need to set up an ext2 filesystem. This can be done
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by running the command:
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<tscreen><verb>
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% mkfs -t ext2 /dev/sdxN
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</verb></tscreen>
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where /dev/sdxN is the name of the SCSI partition. Once you do this,
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you'll be able to mount the partitions and use them as you would any
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other disk (including adding entries in /etc/fstab). </p>
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</sect1>
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<sect1> Hot swapping
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<p> We first tried to test hot swapping by removing a drive and putting
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it back in the DPT-supplied enclosure/tower (which you buy for an
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additional cost). Before we could carry this out to completion, one
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of the disks failed (as I write this, the beeping is driving me
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crazy). Even though one of the disks failed, all the data on the RAID
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drive was accessible. </p>
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<p> Instead of replacing the drive, we just went through the motions
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of hot swapping and put the same drive back in. The drive rebuilt
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itself and everything turned out okay. During the time the disk had
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filed, and during the rebuilding process, all the data was
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accessible. Though it should be noted that if another disk had failed,
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we'd have been in serious trouble. </p>
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</sect1>
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<sect1> Performance
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<p> Here's the output of the Bonnie program, on a 2144 UW with 9x3=17
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GB RAID 5 setup, using the EATA DMA driver. The RAID is on a dual
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processor Pentium Pro machine running Linux 2.0.33. For comparison,
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the Bonnie results for the IDE drive on that machine are also given.
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<tscreen><verb>
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-------Sequential Output-------- ---Sequential Input-- --Random--
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-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
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MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
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RAID 100 9210 96.8 1613 5.9 717 5.8 3797 36.1 90931 96.8 4648.2 159.2
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IDE 100 3277 32.0 6325 23.5 2627 18.3 4818 44.8 59697 88.0 575.9 16.3
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</verb></tscreen>
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</p>
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<p> Some people have disputed the above timings (and rightly so---I've
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been unable to try it out on our machines since they're completely loaded)
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because the size of the file used may have led to it being cached
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(resulting in an unusually good performance report). Here are some
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timings with a 3344 UW controller:
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<tscreen><verb>
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-------Sequential Output-------- ---Sequential Input-- --Random--
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-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
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MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
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1000 1714 17.2 1689 6.0 1200 5.7 5263 40.2 7023 12.1 51.3 2.2
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</verb></tscreen>
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And here are some timings on a SCSI-to-SCSI RAID system:
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<tscreen><verb>
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-------Sequential Output-------- ---Sequential Input-- --Random--
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-Per Char- --Block--- -Rewrite-- -Per Char- --Block--- --Seeks---
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MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU /sec %CPU
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64 7465 100.0 70287 98.7 37012 97.7 8074 99.2 *****100.3 ***** 196.6
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128 7289 99.3 67595 98.5 35294 98.6 7792 97.6 *****100.3 ***** 195.8
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256 7222 98.8 44844 69.6 16096 51.8 5787 72.7 ***** 99.8 ***** 85.2
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512 7138 98.4 13871 23.2 7888 29.3 7183 89.3 16488 27.2 1585. 11.5
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1024 6908 95.8 12270 21.5 7161 25.4 7373 90.4 16527 28.2 123.8 1.8
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2047 6081 84.1 12664 22.6 7191 25.6 7289 89.5 16573 28.5 75.0 1.2
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***** results exceed column width (> 100 MB/sec, > 10000 seeks/sec)
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host: Dual PII 400 MHz, 2 x U2W, 512 MB RAM, no internal disks
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RAID: IFT 3102 UA 128 MB Cache, RAID-5, 6 x 9 GB
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OS: SuSE Linux 6.0 with Kernel 2.2.3
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</verb></tscreen>
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</p>
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</sect1>
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</sect>
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<sect> Features in the EATA DMA driver
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<p> This section describes some of the commands available under Linux
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to check on the RAID configuration. Again, while references to the
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eata_dma driver is made, this can be used to check up on any
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driver. </p>
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<p> To see the configuration for your driver, type:
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<tscreen><verb>
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% cat /proc/scsi/eata_dma/N
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</verb></tscreen>
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where N is the host id for the controller. You should see something
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like this:
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<tscreen><verb>
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EATA (Extended Attachment) driver version: 2.59b
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queued commands: 353969
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processed interrupts: 353969
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scsi0 : HBA PM2144UW
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Firmware revision: v07L.Y
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Hardware Configuration:
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IRQ: 11, level triggered
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DMA: BUSMASTER
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CPU: MC68020 20MHz
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Base IO : 0xef90
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Host Bus: PCI
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SCSI Bus: WIDE Speed: 10MB/sec.
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SCSI channel expansion Module: not present
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SmartRAID hardware: present.
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Type: integrated
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Max array groups: 7
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Max drives per RAID 0 array: 7
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Max drives per RAID 3/5 array: 7
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Cache Module: present.
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</verb></tscreen>
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<tscreen><verb>
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Type: 0
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Bank0: 16MB without ECC
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Bank1: 0MB without ECC
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Bank2: 0MB without ECC
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Bank3: 0MB without ECC
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Timer Mod.: present
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NVRAM : present
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SmartROM : enabled
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Alarm : on
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Host<->Disk command statistics:
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Reads: Writes:
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1k: 0 0
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2k: 0 0
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4k: 0 0
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8k: 0 0
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16k: 0 0
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32k: 0 0
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64k: 0 0
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128k: 0 0
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256k: 0 0
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512k: 0 0
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1024k: 0 0
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>1024k: 0 0
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Sum : 0 0
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</verb></tscreen>
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</p>
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<p> To get advanced command statistics, type:
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<tscreen><verb>
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% echo "eata_dma latency" > /proc/scsi/eata_dma/N
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</verb></tscreen>
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</p>
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<p> Then you can do a:
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<tscreen><verb>
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% cat /proc/scsi/eata_dma/N
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</verb></tscreen>
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to get more detailed statistics. </p>
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<p> To turn off advanced command statistics, type:
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<tscreen><verb>
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% echo "eata_dma nolatency" > /proc/scsi/eata_dma/N
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</verb></tscreen>
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</p>
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</sect>
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<sect> Troubleshooting
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<sect1> Upon bootup, no SCSI hosts are detected
|
|
|
|
<p> This could be due to several reasons, but it's probably because
|
|
the appropriate driver is not configured in the kernel. Check and make
|
|
sure the appropriate driver (EATA-DMA or EATA ISA/EISA/PCI for most
|
|
DPT cards) is configured. </p>
|
|
|
|
</sect1>
|
|
|
|
<sect1> RAID configuration shows up as N different disks
|
|
|
|
<p> The RAID has not been configured properly. If you're using a DPT
|
|
storage manager, you need to configure the RAID disks as a single
|
|
logical array. Michael Neuffer (<htmlurl
|
|
url="mailto:neuffer@uni-mainz.de"
|
|
name="neuffer@uni-mainz.de">) writes: "When you configure
|
|
the controller with the SM start it with the parameter /FW0 and/or
|
|
select Solaris as OS. This will cause the array setup to be managed
|
|
internally by the controller." </p>
|
|
|
|
<sect1> Machine/controller is shut down in the middle of a format
|
|
|
|
<p> As stated in the DPT manual, this is clearly a no-no and might
|
|
require the disks to be returned to the manufacturer, since the DPT
|
|
Storage Manager might not be able format it. However, you might be
|
|
able to perform a low level format on it, using a program supplied by
|
|
DPT, called clfmt in their utilities page. Read the
|
|
instructions after unzipping the clfmt.zip file on how to use it (and
|
|
use it wisely). Once you do the low level format, you might be able to
|
|
treat the disks like new. Use this program carefully! </p>
|
|
|
|
</sect1>
|
|
|
|
<sect1> SCSI_ABORT_BUSY errors produced during initial filesystem format
|
|
|
|
<p> When you do a <tt>mke2fs</tt> on the SCSI drive, you may see errors
|
|
of the form:
|
|
|
|
<tscreen><verb>
|
|
scsi: aborting command due to timeout : pid xxx, scsi0, channel 0, id
|
|
2, lun 0
|
|
write (10) xx xx xx xx xx xx xx xx xx
|
|
eata_abort called pid xxx target: 2 lun: 0 reason: 3
|
|
Returning: SCSI_ABORT_BUSY
|
|
</verb></tscreen>
|
|
|
|
and this might end up causing the machine to freeze. I (and many
|
|
others) have been able to fix this problem by simply reading one or
|
|
two hundred MB from the RAID array with <tt>dd</tt> like this:
|
|
|
|
<tscreen><verb>
|
|
% dd if=/dev/sdX of=/dev/null bs=1024k count=128
|
|
</verb></tscreen>
|
|
|
|
</p>
|
|
|
|
<p> During a format, a fast rush of requests for chunks of memory that
|
|
is directly accessible is made, and sometimes the memory manager
|
|
cannot deliver it on time anymore. The <tt>dd</tt> is a workaround
|
|
that will simply create the requests sequentially instead of one huge
|
|
heap at once like the format tends to create it. </p>
|
|
|
|
</sect1>
|
|
|
|
<sect1> If all fails...
|
|
|
|
<p> Read the SCSI-HOWTO again. Check the cabling and the termination.
|
|
Try a different machine if you have access to one. The most common
|
|
cause of problems with SCSI devices and drivers is because of faulty
|
|
or misconfigured hardware. Finally, you can post to the various
|
|
newsgroups or e-mail me, and I'll do my best to get back to you. </p>
|
|
|
|
</sect1>
|
|
|
|
</sect>
|
|
|
|
<sect> References <label id="references">
|
|
|
|
<p> The following documents may prove useful to you as you set up
|
|
RAID:
|
|
|
|
<itemize>
|
|
<item> <url url="http://www.dpt.com/library/library.html" name="DPT Technology Library">
|
|
<item> <url url="http://www.uni-mainz.de/~neuffer/scsi/dpt/index.html" name="EATA-DMA homepage">
|
|
<item> <url url="http://sunsite.unc.edu/mdw/HOWTO/Disk-HOWTO.html" name="Linux Disk HOWTO">
|
|
<item> <url url="http://sunsite.unc.edu/mdw/HOWTO/Kernel-HOWTO.html" name="Linux Kernel HOWTO">
|
|
<item> <url url="http://sunsite.unc.edu/mdw/HOWTO/SCSI-HOWTO.html" name="Linux SCSI HOWTO">
|
|
<item> <url url="http://www.nyx.net/~sgjoen/disk.html" name="Multi Disk System Tuning HOWTO">
|
|
<item> <url url="http://linas.org/linux/raid.html" name="RAID Solutions for Linux">
|
|
</itemize>
|
|
</p>
|
|
|
|
</sect>
|
|
|
|
<sect> Acknowledgements
|
|
|
|
<p> The following people have been helpful in getting this HOWTO
|
|
done:
|
|
|
|
<itemize>
|
|
<item> Andreas Koepf (<htmlurl url="mailto:A_Koepf@icp-vortex.com" name="A_Koepf@icp-vortex.com">)
|
|
<item> Boris Fain (<htmlurl url="mailto:fain@zen.stanford.edu" name="fain@zen.stanford.edu">)
|
|
<item> Dario Ballabio (<htmlurl url="mailto:Dario_Ballabio@milano.europe.dg.com" name="Dario_Ballabio@milano.europe.dg.com">)
|
|
<item> Heiko Rommel (<htmlurl url="mailto:Heiko.Rommel@Uni-Bielefeld.DE" name="Heiko.Rommel@Uni-Bielefeld.DE">)
|
|
<item> Jos Vos (<htmlurl url="mailto:jos@xos.nl" name="jos@xos.nl">)
|
|
<item> Michael Neuffer (<htmlurl url="mailto:neuffer@uni-mainz.de" name="neuffer@uni-mainz.de">)
|
|
<item> Ralph Wallace (<htmlurl url="mailto:rwallace@rwallace.interaccess.com" name="rwallace@rwallace.interaccess.com">)
|
|
<item> Russell Brown (<htmlurl url="mailto:russell@lutton.lls.com " name="russell@lutton.lls.com">)
|
|
<item> Syunsuke Ogata (<htmlurl url="mailto:Syunsuke_Ogata@appear.ne.jp" name="Syunsuke_Ogata@appear.ne.jp">)
|
|
<item> Tom Brown (<htmlurl url="mailto:tbrown@baremetal.com" name="tbrown@baremetal.com">)
|
|
</itemize>
|
|
</p>
|
|
|
|
</sect>
|
|
|
|
</article>
|