Managing RAID on Linux - Derek Vadala [87]
EzAssist (RAID configuration)
EzAssist is the primary utility used to configure Mylex controllers and arrays. It is normally invoked when the controller initializes, but can also be installed on a floppy disk and run from an MS-DOS compatible operating system. The latter option is useful when attempts to enter EzAssist at system startup fail. You can download EzAssist from the Mylex web site.
After you press ALT-R to enter the EzAssist RAID configuration menu, the following messages appear on the screen:
Checking RAID Configuration Software ...
Loading RAID Configuration Software ...
Starting RAID Configuration Software ...
An ASCII animation of the forward slash and backslash characters will appear immediately following the last line. Be aware that on slow systems, it could take some time for the software to start, and the animation will move slowly.
Once the software loads, you will be presented with a list of all Mylex controllers connected to the system. In many cases, you will see a single controller with an entry such as the following:
Controller PCI PCI PCI Firmware
No. Model Bus Device Function Version
0 AcceleRAID 352 2 13 0 7.00-03
Navigate the list using the arrow keys and press ENTER when the controller that you wish to administer is highlighted. After rescanning the SCSI bus, if no arrays are currently defined and there are disks connected to the controller, EzAssist will ask if you wish to configure a new array. Otherwise, the following menu options are presented:
Configure a RAID Drive
View or Modify Controller Configuration
Perform Administration On ...
Rescan for New Devices
Advanced Options
In order for you to install any operating system on disks connected to a Mylex controller, at least one array must be defined. If you already have an operating system installed, you can create additional arrays using either the EzAssist BIOS utility or the Global Array Manager, once Linux has booted.
Configuring the first array
Before you can install Linux, at least one array must be created. The following instructions explain how to configure an array.
Use ALT-R to enter the EzAssist RAID configuration utility.
Select your controller.
If a dialog pops up, warning that no configuration was detected, answer yes. Otherwise, choose Configure RAID Drive from the main menu.
A menu with three configuration methods will appear: Automatic, Assisted, and Custom. Choose Custom and then select Configure a New Disk Array from the menu that appears.
The next menu contains a list of all disks connected to the controller, organized by SCSI ID. Select all the disks that you want to include in the new array by highlighting them and pressing the ENTER key. When you are done selecting disks, navigate to and choose Save Array.
If there are other unconfigured disks connected to the controller, a dialog will appear, asking if you want to configure logical drives. Choose yes, and then select the array that you just defined from the pop-up dialog that follows.
The next screen displays information about your new array. Use the arrow keys to move between fields and make any necessary changes to the array configuration. You can change the RAID level, cache type, and stripe size. In addition, you can alter the array's logical size by moving to the logical size field, using the arrow keys, and typing in the new logical drive size. Changing an array's logical size is useful for splitting a single array into two or more smaller logical drives. As mentioned earlier in this chapter, the DAC960/DAC1100 driver supports only seven disk partitions. So if you need more than that for a large array, you will have to split up the array into more than one logical drive. See the Partition limitations and Logical Drives sections, earlier in this chapter.
After you have customized your array settings,