Note: The information contained in this article is structured as help information for the System Management Interface Tool (SMIT) and is not intended for general reading.
Identifies the logical name of the disk device.
Identifies the predefined device type of the disk.
Identifies the type of disk interface. This is the same as the predefined device subclass of the disk.
Provides a short text description of the disk device.
Indicates the current status of the disk device. Possible values are available, indicating that the disk device is configured in the system and ready to be used, and defined, indicating that the disk device is defined to the system but not configured.
Identifies the logical name of the adapter device to which the disk is or will be attached.
Identifies the logical name of the controller device to which the disk is attached or will be attached.
Indicates the SCSI ID and logical unit number (LUN) used to address the disk drive. The format is x,y where the x variable is the SCSI ID and the y variable is the logical unit number. Typical SCSI devices have mechanical switches for setting these values.
Identifies the logical unit number (LUN) used to address the disk drive.
The maximum size of transactions, in bytes, that the disk driver will issue to the adapter driver. The adapter driver has its own maximum transfer size that is independent of the disk driver setting. The adapter driver's maximum transfer size can also be configured based on the adapter attribute that determines DMA resources allocated to it. If the disk driver's max_transfer size is larger than the adapter driver's maximum transfer size, the adapter's maximum transfer size takes precedence. The default value is 256KB(0x40000).
It is important to understand when to change this value. For standard systems, the default value set is satisfactory. To determine the best value for your system, consider the kind of operations it is performing. A disk's max_transfer size can be higher for I/O solutions that perform large size I/O operations. The most significant performance improvement is achieved for those I/O solutions that perform large sequential transactions. For solutions performing small sized transactions, increasing the max_transfer size does not improve performance.
Setting the max_transfer size too large degrades system performance by starving other devices on the bus. If there is more than one device on the same adapter and each of the devices have the max_transfer size set to be equal to the max_transfer size of the adapter, these devices will be throttled because only one transaction at a time will be possible.
The adapter driver has limited DMA resources. If you change the max_transfer size of the disk, consider both the maximum data transfer size of the adapter and the queue depth (if it can be configured). The maximum data transfer size of the virtual SCSI client adapter cannot be configured in the client partition.