How to Create a LUN

Use this procedure to create a logical unit number (LUN) from unassigned disk drives or remaining capacity. See the Sun StorEdge RAID Manager Release Notes for the latest information about LUN administration

This product supports the use of hardware RAID and host-based software RAID. For host-based software RAID, this product supports RAID levels 0+1 and 1+0.

You must use hardware RAID for Oracle Parallel Server (OPS) data stored on the Sun StorEdge A3500/A3500FC arrays. Also, do not place OPS data under volume management control. You must place all non-OPS data stored on the arrays that are under volume management control. Use either hardware RAID, host-based software RAID, or both to manage your non-OPS data.

Hardware RAID uses the Sun StorEdge A3500/A3500FC system's hardware redundancy to ensure that independent hardware failures do not impact data availability. Host-based software RAID ensures that independent hardware failures do not impact data availability when an entire array is offline by mirroring across separate arrays. Although you can use hardware RAID and host-based software RAID concurrently, you need only one RAID solution to maintain a high degree of data availability.

When using host-based software RAID with hardware RAID, the hardware RAID levels you use affect the hardware maintenance procedures because they affect volume management administration. If you use hardware RAID level 1, 3, or 5, you can perform most maintenance procedures in "Maintaining a Sun StorEdge A3500/A3500FC System" without volume management disruptions. If you use hardware RAID level 0, some maintenance procedures in "Maintaining a Sun StorEdge A3500/A3500FC System" require additional volume management administration because the availability of the LUNs is impacted.

1. With all cluster nodes booted and attached to the Sun StorEdge A3500/A3500FC system, create the LUN on one node.

   Shortly after the LUN formatting completes, a logical name for the new LUN appears in /dev/rdsk on all cluster nodes attached to the Sun StorEdge A3500/A3500FC system.

   For the procedure on creating a LUN, see the Sun StorEdge RAID Manager User's Guide.

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   Note -

   If the following warning message is displayed, ignore it and continue with the next step: scsi: WARNING: /sbus@40,0/SUNW,socal@0,0/sf@1,0/ssd@w200200a0b80740db,4 (ssd0): corrupt label - wrong magic number

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   Note -

   Use the format(1M) command to verify Solaris logical device names.

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2. Copy the /etc/raid/rdac_address file from the node on which you created the LUN to the other node to ensure consistency across both nodes.

3. Ensure that the new logical name for the LUN you created in Step 1 appears in the /dev/rdsk directory on both nodes by running the hot_add command on both nodes:

   # /etc/raid/bin/hot_add

4. On one node, update the global device namespace:

   # scgdevs

5. Use the scdidadm command to verify that the DID numbers for the LUNs are the same on both nodes. In the sample output shown below, the DID numbers are different:

   # scdidadm -L ... 33 e07a:/dev/rdsk/c1t4d2 /dev/did/rdsk/d33 33 e07c:/dev/rdsk/c0t4d2 /dev/did/rdsk/d33

6. Are the DID numbers output from Step 5 the same for both your nodes?

   • If the DID numbers are the same, go to Step 7.

   • If the DID numbers are different, perform the procedure in "How To Correct Mismatched DID Numbers" before you continue with Step 7 of this procedure.

7. If you want a volume manager to manage the new LUN you created in Step 1, run the appropriate Solstice DiskSuite or VERITAS Volume Manager commands to incorporate the new LUN into a diskset or disk group.

   For more information, see your Solstice DiskSuite or VERITAS Volume Manager documentation.

Do not configure StorEdge A3500/A3500FC LUNs as quorum devices; using StorEdge A3500/A3500FC LUNs as quorum devices is not supported.