Managing RAID on Linux - Derek Vadala [82]
One possible solution is that at most places of business, there are systems running Microsoft operating systems. You can easily create a bootable DOS disk on such systems and place the necessary utilities and firmware revisions on them. Unfortunately, I believe that this is illegal.
Fortunately, there are a few workarounds that are relatively hassle-free. Most hard disk manufactures provide drive test utilities that come with bootable disks. You can download one of these bootable floppy disk images from a hard disk vendor's web site, mount the filesystem under another Linux system, and erase the contents of the disk, replacing them with your firmware and BIOS upgrades. Or you can use FreeDOS.
FreeDOS
If you don't have access to a Microsoft operating system to generate a bootable DOS disk and upgrade system hardware, you will find FreeDOS very useful. FreeDOS is a free (GPL) MS-DOS-compatible operating system. You can download a bootable disk image from the FreeDOS web site (http://www.freedos.org) and use it to upgrade system hardware with vendor-supplied utilities.
First, download a disk image from freedos.org. For each release, a subdirectory named instdisk contains bootable disk images for floppy drives of various sizes. For example, instdisk/1.44 contains bootable images for 1.44 MB floppy disks. Download the file FD8_144.DSK from the directory:
ftp://ftp.ibiblio.org/pub/micro/pc-stuff/freedos/files/distributions/beta8/
Next, use dd to write the disk image onto a blank floppy disk:
# dd if=/home/derek/FDB8_144.DSK of=/dev/fd0H1440 bs=1k
Format another floppy disk and create an MS-DOS filesystem on it:
# fdformat /dev/fd0
# mkfs.msdos /dev/fd0
Next, mount the newly formatted disk:
# mount -t msdos /dev/fd0 /mnt/floppy
Copy the firmware upgrades you downloaded from your vendor to the disk. Next, boot the system with the FreeDOS disk inserted. After the system starts, insert the disk with the firmware upgrades and run the vendor-provided utility to update your controllers and disks. You might need to create more than one blank disk in order to store all the firmware files and utilities. Some of them will fill an entire 1.44 MB floppy disk.
General Configuration Issues
While each Linux-compatible RAID controller has vendor-specific drivers and configuration utilities, they all share some common semantics.
Controller Card BIOS
Like motherboards, most RAID controllers (and even many standard disk controllers) have an onboard controller BIOS. The controller BIOS performs many of the same tasks as the BIOS on a motherboard (such as low-level disk maintenance and configuration) and also provides an interface for configuring and managing RAID devices. While some manufacturers also provide user-space tools, you will need to configure the first array using the controller's BIOS if you plan to install an operating system onto an array, and in some cases, even if you plan to install Linux directly to a standalone disk connected to a RAID controller.
If you are interested only in adding a new array to an existing system, and not in adding RAID support to your existing system disks (that is, you plan to keep your existing disk controller), you might be able to utilize user-space tools to configure and initialize arrays. However, not all vendors provide tools to manage controllers using Linux. Please see the specific controller sections later in this chapter for more information, or check with your vendor if you are using a controller that isn't covered in this chapter.
Even if you have user-space tools available, you may wish to use the onboard BIOS to configure arrays. Vendor-provided management tools