7
Using “Automatic Configuration” to create a RAID5 array with 3 or more drives
1.
To create a RAID5 array using 3 or more identical drives choose “Automatic Configuration” from the Main
Menu of the DACCF utility.
2.
The program will prompt “Do you wish to have a standby drive”. A standby drive is also known as a “Hot
Spare”. A standby drive is an installed, unused drive that automatically replaces a drive that fails. It must be in
addition to the drive required for the RAID (i.e. at least 3 1 for the standby.) The standby drive should
be an identical drive to the drives in the RAID but a larger drive may be used. If a Standby drive is available
and desired choose <
Yes
>. “Do you want to have Write Cache enabled?” Select <
NO
> to set the write policy of
the system drive to “write through”. Select <
YES
> to set the write policy to “write back”. The system will
show: “Saving Configuration, please wait.”
Write back or Write Through?
A write back policy results in better performance under light to medium loads
at the expense of fault tolerance. In a power failure/system crash, any data in
the cache will be lost. A write through policy will result in lower
performance, but no data can be lost in a power failure/system crash.
3.
A screen will appear which details the number of system drives, RAID level, cache settings, number of physical
drives, and capacity of the drives. It should also display “Automatic Configuration successfully done. Created
system drive is available for immediate use.”
4.
Select <
Enter
> to go to the main menu.
5.
Proceed to the section titled “
6.
Backing up the configuration information to a
floppy”
Using “New Configuration” to create a custom RAID array
1.
At the Main Menu of the DACCF utility choose “New Configuration”.
2.
Under the “New Configuration” menu choose <
1. Define Pack
>
3.
The table on the left shows boxes for each possible drive location. A status will appear in each box for which a
drive is installed under the appropriate channel and drive ID. Drives that are installed and ready will have
“RDY” displayed. “ONL” represents drives that are currently online. A “RDY” drive can be assigned to a
RAID pack (or array).
4.
Use the arrow keys to move around on the drive table, select <
Enter
> on each drive that you wish to be included
in the RAID. Each selected drive will change from “RDY” to “ONL”. Note: Drives with higher ID’s (above 6)
will be off the screen – you will have to arrow down to see them and select them.
5.
When the desired number of drives has been selected select <
ESC
> to return to the “Pack Definition” menu.
Note: if all available drives are selected it will automatically return to the “Pack Definition” menu.
6.
Choose <
Arrange Pack
>.
7.
Arrow to one of the drives you have selected and select<
Enter
>.
8.
The program will return you to the “New Configuration” Menu – choose <
2. Define System Drive
>.
9.
At “System Drive Definition” choose <
1. Create System Drive
>
10.
Choose the “RAID Level” you desire (depends on the performance / redundancy tradeoff required for your
application). Refer to the introduction of this document for more information on RAID levels.
11.
“Enter Size (MB):” Type a value in the window less than or equal to the default value. This default value is the
amount of space which is yet unassigned on the RAID array. You can create multiple System “drives” till the
RAID array space is fully used.
12.
When finished creating system drives, select <
ESC
> twice to exit the Configuration section of DACCF.
13.
At the “Save Configuration?” prompt choose <
YES
>.
14.
Proceed to the next section:
15.
Backing up the configuration information to a
floppy
