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Document ID: DDSE-3QNJ2V

PC Server 720 - Performing common tasks (RAID configure)

Applicable to: World-Wide

Performing Common Tasks (RAID Configuration)
The Create/Delete Array menu of the RAID configuration program contains the more common tasks for configuring disk arrays.

Procedures to complete these tasks are contained in this section as follows
- 'Defining a Hot-Spare Drive´
- 'Deleting a Disk Array´
- 'Creating a Disk Array´
- 'Defining Logical Drives´

Defining a Hot-Spare Drive
To define a drive as a hot-spare drive:
1. Start the RAID configuration program. See 'Starting the RAID Configuration Program´.
2. Select Create/delete array from the Main Menu. The Create/Delete Array screen appears.
3. Select Define hot-spare drive. The cursor will become active in the Bay/Array selection list.

Note
Only SCSI hard disk drives are shown as RDY, ONL, DDD, OFL, or HSP state. SCSI tape and CD-ROM drives are not shown. They appear when you select drive information. Refer to 'Bay/Array Selection List´ for the drive status meanings.

The numbers shown on the left are the bay IDs. See 'Installing Internal Drives (Type 8642)´ for an explanation of the bay IDs.
4. Use the Up Arrow (« ) key or the Down Arrow (» ) key to highlight the RDY (ready) drive you want to define as the hot spare; then press Enter. The RDY changes to HSP (hot spare). You can press Enter again to toggle between HSP and RDY.
5. Press Esc when you have finished. The cursor will become active in the Create/Delete Array menu.
6. If you want to create a disk array, go to 'Creating a Disk Array.´
7. If you are finished:
a. Select Exit or press Esc. A pop-up window will appear asking you to confirm your change.

Note
The changes you make are not saved until you confirm them by selecting Yes in the Confirm pop-up window.

b. Select No if you do not want the drive you selected to be a hot spare; select Yes to define it as a hot-spare drive.
c. Back up the disk-array configuration information to diskette. Refer to 'Backing Up Your Disk-Array Configuration´ on for instructions.

Deleting a Disk Array
The last array created must be the first deleted.

Warning
All the data and programs in the array are lost during this procedure. Before proceeding, back up any data and programs that you want to save.

To delete a disk array
1. Start the RAID configuration program. See 'Starting the RAID Configuration Program´ .
2. Select Create/delete array from the Main Menu.
3. Select Delete disk array from the Create/Delete Array menu. The cursor will be active in the Array list.
4. Review the Date Created column in the Logical Drive list; then press the Up Arrow (« ) key or the Down Arrow (» ) key to highlight the most recently defined array.
5. Press Del. The Confirm pop-up window appears.
6. If you do not want to delete the array, select No. To delete the array, select Yes.

Note
To use hard disks from the existing array when creating a new array, you must confirm the deletion of the existing array.

If a defective drive is still in a bay, the status shows a blank bay, as though there is no drive in that bay. When you replace the drive, the status will show RDY after you reconfigure and select Yes in the Confirm pop-up window.

Note
In some operating systems, deleting an array and associated logical drives might change the drive letters assigned to the existing drives.

Creating a Disk Array

To create a disk array:
1. Start the RAID configuration program. See 'Starting the RAID Configuration Program´.

Note
To create an array using hard disks in an existing array, refer to 'Redefining Space in an Array´.

2. Select Create/delete array from the Main Menu.
3. Select Create disk array from the Create/Delete Array menu.

The cursor will be active in the Bay/Array selection list.

Important
In the following step, when you press Enter to select a drive for an array, you cannot deselect it by pressing Enter again, as you can with the hot-spare selection process. Carefully determine which drives you want to include in the array before beginning the selection process.
If you change your mind after selecting the drives for an array, you can delete the array (by selecting Delete disk array from the Create/Delete Array menu) and begin again.

4. Select each drive you want in the array by using the Up Arrow (« ) key or the Down Arrow (» ) key to highlight the drive and then pressing Enter. As you select each drive, the status will change from RDY (Ready) to ONL (Online).
5. When you have selected all the drives you want to include in the array, press Esc. The cursor will become active in the menu.
6. If you have drives you did not use in this array and you want to create another array, you can do one of the following:
- Define the logical drive or drives for this array; then create another array and its logical drives. See 'Defining Logical Drives.´
- Create another array now by repeating steps 2 through 5 in this procedure; then define logical drives for both arrays.

Note
You must define at least one logical drive for each created array before you can exit the configuration program.

Continue with 'Defining Logical Drives´.

Adding Drives to Create an Additional Array

To add storage capacity to your server without disturbing existing data:
1. Install the additional hard disk drive or drives. (See 'Installing Internal Drives (Type 8642)´.)
2. Start the RAID configuration program. (See 'Starting the RAID Configuration Program´.)
3. Create a new disk array and define logical drives. (See 'Creating a Disk Array´ for additional information.)

Defining Logical Drives
After you have created an array, you must define a logical drive. (You cannot leave the RAID configuration program until you define the logical drives for any created arrays.)

To define a logical drive
1. Select Define Logical drive from the Create/Delete Array menu. The Create/Delete Array menu screen appears; the cursor is active in the Array list.
2. Use the Up Arrow (« ) key or the Down Arrow (» ) key to highlight the array you want to define; then press Enter. The Select RAID Level pop-up window appears, and the cursor is active in the window.

Note
The system automatically assigns RAID level 0 to any logical drives defined in an array containing only one hard disk drive. When this is the case, the Select RAID Level pop-up window will not appear.

If you have only two hard disk drives in the array, the Select RAID Level pop-up window appears, but RAID level 5 is not selectable because you need at least three hard disk drives in an array to assign RAID level 5 to one of the logical drives. You can define more than one logical drive for your array. The only restriction is that the maximum number of logical drives you can define is eight.
3. Use the Up Arrow (« ) key or the Down Arrow (» ) key to highlight the RAID level you want to assign to these logical drives then press Enter.

Note
Because the level you assign can influence the space needed for the drive, you must assign a RAID level before you enter the size of the logical drive.

The Logical Drive list shows you the logical drive ID, the size of each logical drive, the RAID level you assigned to that logical drive, and the date that the logical drive was created.

The status of the logical drive also is shown.

Good

All is well with the drive.

Critical

You must replace the hard disk drive or do a rebuild operation. (You will have received a message telling you what has happened to the drive.)

Offline

The logical drive is unrecoverable; the data on that drive is lost.



The Logical Drive Size pop-up window shows the space in this array that is available for logical drives.

4. Type the size, in megabytes, that you want for the logical drive; then press Enter. A pop-up window appears asking you to confirm your action.

Information about the new logical drive appears in the Logical Drive list.

Note
The size appearing in the Logical Drive list might be different from the size you typed because it appears in binary equivalent.

The size of a logical drive is determined by a number of factors, but basically the size must be divisible by the number of drives in the array.

Consider the following examples:

Example 1
There are three 1GB drives in the array. You assign RAID level 0 (which uses all the drives in the array with no parity storage), and type '1000MB.´ The 'Size (MB)´ will be 999, which is the number closest to and lower than 1000 that is divisible by 3.

Example 2
There are three 1GB drives in the array, and you assign RAID level 5. Data is striped across all three drives in the array, but the space equivalent to that of one drive is used for redundant storage. Therefore, if you type '1000MB,´ the 'Size (MB)´ remains 1000 because it is divisible by 2 (drives), which is the space available for data.

If you do not use the entire array for this logical drive, you can create another by assigning either the same or a different RAID level for an additional logical drive. You can have as many as eight logical drives among four disk arrays.
5. To return to the Create/Delete Array menu, press Esc. To define more logical drives, repeat steps 1 through 5 of this procedure.
6. To leave this screen, select Exit or press Esc. A pop-up window appears asking you to confirm your action.
7. To save your changes, select Yes. To maintain the disk-array configuration that was in place before you made changes, selectNo.
8. If you are using RAID level 1 or RAID level 5, you must select Initialize logical drive for proper operation. This sets the drive to a predetermined state. Any data existing on the drive is overwritten with zeros, and corresponding parity is initialized to the correct value.
a. Select Initialize/synchronize array from the Main Menu; then select Initialize logical drive.
b. Select the logical drives you want to initialize from the Logical Drive list by pressing the Spacebar (the selected drives will appear highlighted). To start the initialization, press Enter. A pop-up window appears asking you to confirm your action.

Warning
If you select Yes in the Confirm pop-up window, information in the logical drive will be overwritten with zeros.

c. Select Yes to confirm that you want to initialize this logical drive.
The initialization process begins, and you can see its progress in the Pct. Int. (Percent
Initialized) column of the Logical Drive list.
d. To stop the initialization at any time, press Esc. Then press Esc again to return to the menu, or press Enter to continue initializing the drive.
9. To back up the disk-array configuration to diskette, you will need a 3.5-inch formatted diskette.

To back up the disk-array configuration
a. Select Advanced functions from the Main Menu.
b. Select Backup config. to diskette.

Follow the instructions on the screen. A pop-up window shows the default file name of CONFIG. You can change the file name by typing over the default.

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Hint Category

Hard Drives, Hardware Maintenance Information

Date Created

20-08-96

Last Updated

22-01-99

Revision Date

29-09-99

Brand

IBM PC Server

Product Family

PC Server 720

Machine Type

8642

Model

TypeModel

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