9-26 Upgrading Your ServerRAID Controller ConsiderationsNote the following on the configuration of a disk array by using the on-board or optional disk arraycontroller. To change the disk array configuration or the RAID, the hard disk drives must beinitialized. If important data is saved in the hard disk drives used to constitute a diskarray, first back up the data in other hard disk drives before installing boards andconfiguring the disk array. At least hard disk drives are required to configure a disk array. Hard disk drives used in the disk array configuration should have the same disk revolutionrate and capacity in packs. See the table on the next page for the slot in which an optional board can be installed. Up to three disk array controller boards can be installed in the server. Several RAID (Redundant Arrays of Inexpensive [Independent] Disks) levels can be setfor the disk array configuration in the server. See "Disk Array Configuration" describedlater for available RAIDs, data transfer rate, and array configurationFor optional disk array controller, refer to the documentation coming with the disk arraycontroller for details. The available capacity of the hard disk drives in the disk array configuration is lower thanthe total capacity of the hard disk drives configuring the disk array while the diskreliability is improved (for RAID 1, 5, 10, or 50). Set "Option ROM Scan," a parameter of the slot in which a hard disk is installed, to"Disabled" in "PCI Configuration" on the Advanced menu of the BIOS SETUP utility.(The "Enabled" is factory-set.) If two or more disk array controllers are installed, set onlythe slot containing the board to boot-up to "Enabled". Do not set "Option ROM Scan" forembedded SAS to "Disabled". Replacement of optional disk array controller boardBack up the disk array configuration information in the disk array controller board to thefloppy disk and restore it to the replaced disk array controller board. Refer to the manualthat comes with the disk array controller for details.When more than one disk array controller board are installed in the server, install the diskarray controller board to which the system disk is connected in the PCI slot having thehighest boot priority.Boot priority: PCI#3 → PCI#4 → PCI#5 → PCI#8 → PCI#9 → PCI#6 → PCI#7 →PCI#1 → PCI#2For example, if three disk array controller boards are installed in PCI slots #7 to #9, thesystem disk should be connected to the board installed in PCI slot #8. A maximum total capacity of the hard disk drives that are configured as a logical drive ora pack is 2T bytes. A maximum logical disk capacity for installing the Microsoft Windows 2000 operatingsystem or Linux operating system is 1T bytes. For configuration information of onboard RAID (MegaRAID ROMB), you can use Toolsmenu in NEC EXPRESSBUILDER to store or restore the information in/from the floppydisk.
