|C H A P T E R 8|
The "view and edit Host luns" menu allows you to map a partition, logical drive, or logical volume to a host channel. Every partition, logical drive, or logical volume can be mapped more than once to achieve a redundant data path, using multipathing software.
Topics covered in this chapter include:
A logical unit number (LUN) is a unique identifier used on a SCSI channel that enables a host to differentiate between separate devices.
Once you have created logical drives or logical volumes, you can map each storage partition as one system drive (host ID/LUN). The host adapter recognizes the system drives after reinitializing the host bus.
An FC channel can connect up to 126 devices. Each device has one unique ID.
A SCSI bus channel can connect up to 15 devices (excluding the controller itself) when the Wide function is enabled (16-bit SCSI). Each device has one unique ID.
FIGURE 8-1 illustrates the idea of mapping a system drive to a host ID/LUN combination. The FC or SCSI ID is like a cabinet, and the drawers are the LUNs. Each cabinet (ID) can have up to 32 drawers (LUNs). Data can be stored into one of the LUNs of the FC or SCSI ID. Most FC host adapters treat a LUN like another FC or SCSI device.
The maximum number of LUNs that can be created for a Sun StorEdge 3310 SCSI array or Sun StorEdge 3320 SCSI array is 128. To create a total of 128 LUNs, see Planning for 128 LUNs on a SCSI Array (Optional).
The maximum number of LUNs that can be created for a Sun StorEdge 3510 FC array or Sun StorEdge 3511 SATA array in loop configurations is 1024.
The maximum number of LUNs that can be created for a Sun StorEdge 3510 FC array or Sun StorEdge 3511 SATA array in redundant point-to-point configurations is 64. Refer to the Sun StorEdge 3000 Family Installation, Operation, and Service Manual for your array to see more information about point-to-point configurations.
Note - Some versions of operating system software or utilities might not display all mapped LUNs if there is no partition or logical drive mapped to LUN 0. Map a partition or logical drive to LUN 0 if you are in doubt, or refer to your operating system documentation.
Each ID/LUN looks like a storage device to the host computer.
You can create up to 128 LUNs, which is the maximum number of storage partitions that can be mapped on a Sun StorEdge 3310 SCSI array or Sun StorEdge 3320 SCSI array. There are several ways you can meet this requirement. For example, you can set up one of the following configurations:
For details about how to add host IDs, see To Add or Delete a Unique Host ID.
Note - For an overview of how partitions, LUNs, and host IDs work, refer to Mapping a Partition to a Host LUN.
1. Create a minimum of four host IDs.
By default, you have two host IDs: Channel 1 ID 0 (primary controller) and Channel 3 ID 1 (secondary controller). You can have a total of two IDs per channel, one for the primary controller and one for the secondary controller.
See To Add or Delete a Unique Host ID for more information.
2. Confirm that the allowed number of LUNs per host ID is 32.
3. Choose "view and edit Configuration parameters Host-side Parameters."
4. If the "LUNs per Host SCSI ID" setting is not 32, choose "LUNs per Host SCSI ID" and select 32. Then choose Yes to confirm.
5. Create at least four logical drives.
See Creating Logical Drives for more information.
6. Create partitions on each logical drive until you reach a total of 128 partitions.
7. Map those partitions created in Step 6 to the host IDs created in Step 1.
See Partitions and Planning for 128 LUNs on a SCSI Array (Optional) for more information.
If you want to create 1024 LUNs on a Sun StorEdge 3510 FC array or Sun StorEdge 3511 SATA array, which represent the maximum number of storage partitions that can be mapped for these arrays, you must map 32 IDs to the array's host channels. There are several ways you can meet this requirement. For example, you can set up the following configuration described below.
1. If necessary, edit "Host-side Parameters" so "LUNs Per Host SCSI ID" is 32.
For more information, see Step 1 of Planning for 128 LUNs on a SCSI Array (Optional).
2. Ensure that four default host channels (CH 0, 1, 4, and 5) are configured as host channels.
3. Create eight host IDs per host channel (four primary controller IDs and four secondary controller IDs per host channel) for a total of 32 host IDs.
See To Add or Delete a Unique Host ID.
4. Create 32 logical drives.
See Creating Logical Drives.
5. Partition each logical drive into 32 partitions
32 (logical drives) x 32 (partitions per logical drive) = 1024 (partitions).
6. Link the 1024 partitions to the 32 host IDs.
See Partitions and LUN Filtering (FC and SATA Only) for more information.
For FC arrays in point-to-point configurations that use redundant controllers to ensure maximum reliability, accessibility, and serviceability (RAS), you can have a maximum of 64 LUNs. To achieve this redundancy with a maximum number of LUNs, multipathing software is required on each host accessing the array.
Note - Multipathing for FC arrays is provided by Sun StorEdge Traffic Manager software. Refer to the release notes for your array for information about which versions of Sun StorEdge Traffic Manager software are supported on which platforms.
For example, to set up 64 LUNs with multipathing enabled, you can map 32 LUNs to channel 0 on one controller and channel 1 on the other controller, and map the other 32 LUNs to channel 4 on one controller and channel 5 on the other controller.
Refer to the Sun StorEdge 3000 Family Best Practices Manual for your array to see more information about point-to-point and loop storage area network (SAN) and direct-attached storage (DAS) configurations.
See Mapping a Partition to a Host LUN for information about how to map a partition to a LUN on a SCSI array.
See To Map a Logical Drive Partition for information about how to map a partition to a LUN on an FC or SATA array.
This section provides the procedure for deleting a host LUN mapping.
1. Choose "view and edit Host luns" from the Main Menu.
2. Select the channel and ID that are mapped to the host LUN.
3. Select the specific host LUN.
4. Choose Yes to delete the host LUN.
This option deletes the logical drive or logical volume mapping to a host channel. It does not delete the data contained within the logical drive.
See LUN Filtering (FC and SATA Only) for a description and procedure for creating host filter entries.
Prior to using LUN filtering, you need to identify which FC array is connected to which HBA card, and the WWN assigned to each card.
1. If you have a new HBA device installed on your computer, reboot the computer.
2. Type the following command:
3. Scroll down the listing to see the Fibre Channel devices and the related WWNs.
1. Boot a specific host, and note the BIOS version and HBA card models connected to your host.
2. Access the HBA card's BIOS with the appropriate command, such as Alt-Q or Ctrl-A. If the host has multiple HBA cards, select the card that is connected to the storage.
For more information about accessing your BIOS, refer to your system or HBA documentation.
3. Scan the card to look for devices attached to it (usually with the Scan Fibre Devices or the Fibre Disk Utility).
The node name (or similar label) is the WWN. The following example shows the node name for a Qlogic card.
Note - Refer to appendixes in the Sun StorEdge 3000 Family Installation, Operation, and Service Manual for your FC or SATA array to see information about determining the WWN for servers running HP-UX or IBM AIX, and for more detailed information regarding WWNs on all supported platforms.
Use the "view and edit Host luns Edit Host-ID/WWN Name List" menu option to manually add to the current device list any HBA worldwide names that have not been automatically propagated to the array. You can add up to 64 WWNs per array.
Note that when you add a worldwide name using this menu option, that worldwide name appears to be available to all channels. Ensure that, when you create a filter for a worldwide name that has been added using the "Edit Host-ID/WWN Name List" menu option, you also create the filter on a channel where the HBA is connected.
Note - You can also manually add worldwide names using the "Manual add host filter entry" menu option when you are configuring a host filter. When you use the "Manual add host filter entry" option, the worldwide name you add is only displayed in the worldwide name list when you create a filter on the channel where that worldwide name was entered.
Once you have created host filter entries you can display detailed information about them.
Note - If you have host filter entries for two or more WWNs, an asterisk next to an entry indicates that more information is available than is currently displayed. To display the additional information, select the entry and press Enter.
1. Choose "view and edit Host luns."
2. Select the channel and ID mapped to the host LUN.
3. Select the filtered LUN.
4. Choose "View and edit host filtering."
5. Select the Host-ID/WWN whose information you want to view or edit.
6. Choose "View Host Filter Information" to see detailed information about that filter.
7. Choose "Add Host Filter Entry" to add another filter.
See LUN Filtering (FC and SATA Only) for the steps to follow once you choose this menu option.
8. Choose "Delete Filter Entry" to delete the current filter.
9. Choose "Add Host-ID/WWN Name List" to manually add a WWN.
See LUN Filtering (FC and SATA Only) for the steps to follow once you choose this menu option.