Increase the Size of a Dump Device

Refer to the following to determine the appropriate size for your dump logical volume and to increase the size of either a logical volume or a paging space logical volume.

• Determining the Size of a Dump Device
• Determining the Type of Logical Volume
• Increasing the Size of a Dump Device

Determining the Size of a Dump Device

The size required for a dump is not a constant value because the system does not dump paging space; only data that resides in real memory can be dumped. Paging space logical volumes will generally hold the system dump. However, because an incomplete dump may not be usable, follow the procedure below to make sure that you have enough dump space.

When a system dump occurs, all of the kernel segment that resides in real memory is dumped (the kernel segment is segment 0). Memory resident user data (such as u-blocks) are also dumped.

The minimum size for the dump space can best be determined using the sysdumpdev -e command. This gives an estimated dump size taking into account the memory currently in use by the system.

For example, enter:

sysdumpdev -e

If sysdumpdev -e returns:

Estimated dump size in bytes: 9830400

The dump device should be at least 9830400 bytes or 12MB if you are using 4MB partition sizes for the disk (three partitions).

Note: When a client dumps to a remote dump server, the dumps are stored as files on the server. For example, the /export/dump/kakrafon/dump file will contain kakrafon's dump. Therefore, the file system used for the /export/dump/kakrafon directory must be large enough to hold the client dumps.

Determining the Type of Logical Volume

1. Enter the sysdumpdev command to list the dump devices. The logical volume of the primary dump device will probably be /dev/hd6 or /dev/hd7.

   Note: You can also determine the dump devices using SMIT. Select the Show Current Dump Devices option from the System Dump SMIT menu.

2. Determine your logical volume type by using SMIT. Enter the SMIT fast path smit lvm or smitty lvm. You will go directly to Logical Volumes. Select the following:
   • List all Logical Volumes by Volume Group

   Find your dump volume in the list and note its Type (in the second column). For example, this might be "paging" in the case of hd6 or "sysdump" in the case of hd7.

Increasing the Size of a Dump Device

If the "Determining the Type of Logical Volume" procedure confirms that your dump device is a paging space, see "Changing or Removing a Paging Space" in AIX Version 4.3 System Management Guide: Operating System and Devices.

If the "Determining the Type of Logical Volume" procedure confirms that your dump device type is sysdump, see "Resizing or Moving the hd6 Paging Space" in AIX Version 4.3 System Management Guide: Operating System and Devices.

Go back to System Dump Facility.