System Management Guide: Operating System and Devices

Configuring a Disk

Three methods can be used to configure a new disk. Once a disk is configured, it is available for use by the system. If the Logical Volume Manager (LVM) is to use this disk, it must also be made a physical volume.

Use Method 0 if you are able to shut down and power off the system before attaching the disk. Otherwise, use Method 1 or Method 2. Use Method 1 if you know only the location of the disk. Use Method 2 if you know more information about the disk, such as the subclass, type, parent name, and where it is connected.

Prerequisites

The new disk must be connected to the system and powered on. Connect the new drive according to the procedure found in the POWERstation and POWERserver Operator Guide.

Attention: If possible, shut down and power off any system to which you are attaching a physical disk.

Procedure

Method 0

Use this method when it is possible to shut down and power off the system before attaching the disk. Upon boot-up, the cfgmgr command automatically configures the disk. After boot-up is complete, log in as root and run lspv, look for a new disk entry in the output. For example:

hdisk1  none                     none

or:

hdisk1  00005264d21adb2e         none

After you have determined the name of the newly configured disk, note whether the new disk is listed with a PVID (16-digit number). If the new disk does not have a PVID, then use the procedure Making an Available Disk a Physical Volume to allow the disk to be used by the LVM. If the new disk did not appear in the lspv output, refer to AIX Version 4.3 Installation Guide.

Method 1

Used this method when it is not possible to shut down or power off the system before attaching the disk.

1. Run the lspv command to note the physical disks already configured on the system. For example:

   hdisk0       000005265ac63976    rootvg
   

2. To configure all newly detected devices on the system (including the new disk) using the configuration manager, type:

   cfgmgr
   

3. Run the lspv command again, and look for a new disk entry in the output:

   hdisk1    none                none
   

   or:

   hdisk1   00005264d21adb2e     none
   

   After you have determined the name of the newly configured disk, use the procedure Making an Available Disk a Physical Volume to allow the disk to be utilized by the Logical Volume Manager. If the new disk is not displayed in the list, refer to AIX Version 4.3 Installation Guide.

Method 2

Used this method when it is not possible to shut down or power off the system before attaching the disk. This method requires more information about the new disk but is usually faster than Method 1. To use method 2, you must know the following information:

• How the disk is attached (subclass)
• The type of the disk (type)
• Which system attachment the disk is connected to (parent name)
• The logical address of the disk (where connected).

Once you have this information, continue through the following steps:

1. Configure the disk and ensure that it is available as a physical volume by typing:

   mkdev -c disk -s subclass -t type -p parentname \
   -w whereconnected -a pv=yes
   

   The pv=yes attribute makes the disk a physical volume and writes a boot record with a unique physical volume identifier onto the disk (if it does not already have one).

   The following is an example for adding a 670 MB disk with a SCSI ID of 6 and logical unit number of 0 to the scsi3 SCSI bus:

   mkdev -c disk -s scsi -t 670mb -p scsi3 -w 6,0 -a pv=yes