A P P E N D I X B

Cabling JBODs

You can connect a Sun StorEdge 3310 JBOD (Just a Bunch of Disks, no controller) array directly to a host server.

This appendix covers the following topics:

Cabling a Single-Bus JBOD with One Host Connection

Cabling a Single-Bus JBOD with Two Host Connections

Cabling a Dual-Bus Single-Initiator JBOD Configuration

Connecting a Dual-Bus JBOD to One Host

Cabling a Dual-Bus, Multi-Initiator JBOD Configuration

Enabling VERITAS DMP in a Single-Bus Configuration

Caution - SCSI IDs are set based on the cabling on the array when it is powered up. If you are switching from single-bus mode to dual-bus mode or vice versa, the SCSI IDs change after you power off, change the cabling, and then power on. If you change SCSI IDs on the array, ensure that your application points to the correct IDs.

Caution - When you connect or disconnect SCSI cables, the host I/O must be inactive.

Caution - The I/O module is hot-serviceable, which means that you can replace it or change its cables while the array is powered on but the SCSI host buses connected to the array must be inactive.

B.1 Known Limitations Affecting Sun StorEdge 3310 SCSI JBOD Arrays

Limitations affecting the Sun StorEdge 3310 SCSI JBOD array are listed below:

Booting from a JBOD disk is not supported in this release.

The mpxio functionality of Sun StorEdge SAN Foundation Suite 4.2 software is not supported with Sun StorEdge 3310 SCSI JBOD arrays.

Only Sun hosts running the Solaris operating system are supported in this release.

Sun Cluster software is not supported in this release.

VERITAS Cluster Server (VCS) software is not supported in this release.

Only direct-attached single-host connections to a single JBOD are supported in this release. There is no multihost support in this release. Daisy-chaining is not supported in this release.

Sun Storage Automated Diagnostic Environment (StorADE) 2.2 software is not supported in this release.

Do not use the luxadm utility to diagnose or manage Sun StorEdge 3310 SCSI JBOD arrays.

Sun StorEdge Configuration Service software supports Sun StorEdge 3310 SCSI JBOD arrays. However, since Sun StorEdge 3310 SCSI JBOD arrays do not have a RAID controller or RAID controller firmware to manage the disks, this software support is necessarily limited. Monitoring functionality that does not require a RAID controller or RAID controller firmware works in the same way it does for RAID arrays.

The Sun StorEdge CLI supports Sun StorEdge 3310 SCSI JBOD arrays. However, since Sun StorEdge 3310 SCSI JBOD arrays do not have a RAID controller or RAID controller firmware to manage the disks, this CLI support is limited to the following sccli commands:

download pld-firmware filename

download safte-firmware filename

download ses-firmware filename

quit

select

version

B.2 Cabling a Single-Bus JBOD with One Host Connection

To connect a JBOD in a single-bus configuration to a single host, connect the following ports:

Connect the bottom left input port to the top right port of the JBOD with the SCSI jumper cable.

Connect the bottom right input port to one host with a SCSI cable.

Caution - Before you disconnect a cable from the array, the host bus on that cable must be inactive.

Caution - If you change SCSI IDs on the array, ensure that your application points to the correct IDs.

FIGURE B-1 A Single-Bus JBOD with One Host Connection (Rear View)

Figure showing JBOD connected to one host, in a single bus configuration.

The following table shows the default SCSI IDs for a 12-drive JBOD when you set up single-bus configuration.


ID 0	ID 3	ID 8	ID 11
ID 1	ID 4	ID 9	ID 12
ID 2	ID 5	ID 10	ID 13

B.3 Cabling a Single-Bus JBOD with Two Host Connections

To connect a JBOD in a single-bus configuration to two hosts, connect the following ports:

Connect the two bottom JBOD input ports with the SCSI jumper cable.

Connect each top JBOD output port to a host server with a SCSI cable.

Caution - Before you disconnect a cable from the array, the host bus on that cable must be inactive.

Caution - If you change SCSI IDs on the array, ensure that your application points to the correct IDs.

FIGURE B-2 A Single-Bus JBOD with Two Host Connections (Rear View)

Figure showing a JBOD connected to two host servers, in a single bus configuration

The following table shows the default SCSI IDs for a 12-drive JBOD when you set up a single-bus configuration. The SCSI IDs are 0-13, with IDs 6 and 7 reserved for host HBA connections.


ID 0	ID 3	ID 8	ID 11
ID 1	ID 4	ID 9	ID 12
ID 2	ID 5	ID 10	ID 13

B.4 Cabling a Dual-Bus Single-Initiator JBOD Configuration

There are two important features to note with the dual-bus single-initiator JBOD configuration:

The bottom input ports on the JBOD must be terminated with an HBA host connection or external terminator. The upper I/O SCSI connectors are auto-terminated.

In a dual-bus configuration, the SCSI ID numbers automatically change according to the cabling.

Single-initiator mode has only one host connection on a SCSI channel.

FIGURE B-4 shows a dual-bus JBOD with two host connections using one host connection to each channel (single-initiator mode). In this example, the array can be connected to two hosts or to two ports on one host. For the single host configuration, this is an efficient way to provide mirroring capability for the single host.

FIGURE B-3 Dual-Bus Single-Initiator JBOD Configuration

A dual bus, single-initiator JBOD configuration

Dual-bus, single-initiator mode: SCSI IDs are 8 to 13 on each channel. In the following table, A and B indicate the two host channels. The table shows the IDs assigned to each channel in the dual-bus configuration.


Channel A ID 8	Channel A ID 11	Channel B ID 8	Channel B ID 11
Channel A ID 9	Channel A ID 12	Channel B ID 9	Channel B ID 12
Channel A ID 10	Channel A ID 13	Channel B ID 10	Channel B ID 13

Note - If you want to have IDs of 0 to 5 and plan to add host connections to the top two ports later, you can put external terminators into the top two ports and preserve the IDs 0 to 5 for the life of the JBOD. For more information, refer to the Sun StorEdge 3000 Family FRU Installation Guide for 2U Arrays.

B.4.1 Connecting a Dual-Bus JBOD to One Host

To connect a dual-bus JBOD, perform the following steps.

1. Stop any I/O on the host bus that will have a cable installed on the bus.

2. Connect each JBOD port to a host.

Caution - The bottom input ports of the JBOD must have a host connection or external terminator to maintain SCSI bus integrity.

Caution - Before you disconnect a cable from the array, the host bus on that cable must be inactive.

Note - SCSI IDs are set based on the cabling on the array when it is powered up. If you are switching from single-bus mode to dual-bus mode or vice versa, the SCSI IDs change after you power off, change the cabling, and then power on.

Note - If you change SCSI IDs on the array, ensure that your application points to the correct IDs.

B.5 Cabling a Dual-Bus, Multi-Initiator JBOD Configuration

An enhanced SCSI JBOD I/O module, part number 370-5396-02/50 or higher, is now used in Sun StorEdge 3310 SCSI arrays. The enhanced SCSI JBOD I/O module now supports dual-bus, multi-initiator JBOD configurations.

The new I/O module implements termination power on all ports. Used primarily in Sun Cluster environments, this enhancement provides easier configuration and enables you to use an external terminator, when required, in any of the four SCSI ports.

If you have earlier I/O modules and do not have JBOD I/O modules with part number 370-5396-02/50 or higher, see "Older JBOD Dual-Bus Configurations" in the latest Sun StorEdge 3000 Family FRU Installation Guide. Refer to the same manual for additional single-bus and dual-bus configurations.

FIGURE B-4 shows a multi-initiator, dual-bus configuration where each host is connected to each host channel. This configuration is common for failover protection in a network cluster environment.

When you remove one or more host cables for maintenance purposes, insert an external terminator into each empty port to maintain the SCSI drive IDs for the active host connections.

Note - The I/O module is hot-serviceable, which means that you can replace it or change its cables while the array is powered on, but the SCSI host buses connected to the array must be inactive.

FIGURE B-4 Dual-Host, Dual-Bus Multi-Initiator JBOD Configuration

Figure showing dual host, dual bus, multi-initiator JBOD configuration.

In this configuration, the dual-bus, multi-initiator mode creates SCSI IDs 0 to 5 on each channel as shown in TABLE B-4.


Channel A ID 0	Channel A ID 3	Channel B ID 0	Channel B ID 3
Channel A ID 1	Channel A ID 4	Channel B ID 1	Channel B ID 4
Channel A ID 2	Channel A ID 5	Channel B ID 2	Channel B ID 5

To connect a dual-bus JBOD to two hosts, perform the following steps.

1. Stop any I/O on the host bus that will have a cable installed on the bus.

2. Connect each JBOD port to a host as shown in FIGURE B-4.

The bottom input ports of the JBOD must have a host connection or external terminator to maintain SCSI bus integrity.

Note - Before you disconnect a cable from the array, the host bus on that cable must be inactive.

Note - SCSI IDs are set based on the cabling on the array when it is powered up. If you are switching from single-bus mode to dual-bus mode or vice versa, the SCSI IDs will change after you power off, change the cabling, and then power on. If you change SCSI IDs on the array, ensure that your application points to the correct IDs.

B.6 Downloading Firmware to Disk Drives in a JBOD

For instructions on how to download firmware to disk drives in a JBOD directly attached to a host, refer to the README file in the patch that contains the firmware.

B.7 Replacing a Disk Drive in a Sun StorEdge 3310 SCSI JBOD Array

Replacing a disk drive is a straightforward operation that involves first removing the defective disk drive and then installing a replacement drive.

Note - If you are using disk management software or volume management software to manage your disk storage, you might need to perform software operations to take a disk offline before you remove it, and after you have replaced a drive to bring it back online. Refer to the documentation that accompanies your disk management software or volume management software for more information.

The drive module is hot-swappable; you can replace it while the array is powered on. To replace a disk drive module, first follow the procedure for removing a disk drive and then follow the procedure for installing a new disk drive.

Note - If you are removing a disk drive that you do not intend to replace, install an air management sled in its place. See Installing an Air Management Sled for more information.

FIGURE B-5 Front View of a Drive Module Pulled Out of the Chassis

Figure showing side view of a drive pulled out of the chassis.

B.7.1 Removing a Disk Drive

To remove a disk drive from an array, perform the following steps.

1. Perform any host software operations necessary to take the disk offline.

2. Unlock the locks with the provided key, and gently pull the plastic front bezel away from the front of the unit so that it drops down and is supported by the two hinged brackets on the sides.

3. Turn the thumbscrew counterclockwise several full turns until the thumbscrew and drive handle are loosened.

4. Gently pull the drive handle upward.

5. Slide the drive module out of the array.

B.7.2 Installing a New Disk Drive

To install a disk drive in an array, perform the following steps.

1. Gently slide the drive module into the drive slot until the handle pins slip into the chassis notch.

2. Lower the disk drive handle until it is vertical.

3. Press and hold the drive handle in while you press the thumbscrew in until it engages the threads.

4. Turn the thumbscrew clockwise until it is finger-tight.

Note - To ensure that a thumbscrew is finger-tight, tighten it with a screwdriver and then loosen the thumbscrew counterclockwise a quarter-turn.

5. Push the plastic front bezel onto the front of the unit until it is seated firmly, and use the key to lock the locks.

6. Perform any operations your host software requires to recognize the new drive and bring it under software control.

B.7.3 Installing an Air Management Sled

The front of an air management sled looks similar to a disk drive module, but the air management sled is an empty box used to maintain optimum airflow in a chassis.

If you have removed a disk drive and do not intend to replace it, insert an air management sled to maintain the optimum airflow inside the chassis. You can install the air management sled by using the same procedure as Installing a New Disk Drive, except that no software operations are necessary.

B.8 Enabling VERITAS DMP in a Single-Bus Configuration

To enable VERITAS Dynamic Multi-Pathing (DMP) support on VERITAS Volume Manager Version 3.2, ensure the HBA device SCSI initiator IDs are unique and then start the system. Perform the following steps.

1. Create a single-bus, multi-initiator configuration that links two cables to two different HBAs.

For details about creating a single-bus multi-initiator configuration, see Cabling a Single-Bus JBOD with Two Host Connections.

2. Stop the server and at the ok prompt, type:

ok setenv auto-boot? false

ok reset-all

ok probe-scsi-all

3. Issue the remaining commands on only one of the paths.

4. Edit or create the nvramrc to set the SCSI-initiator-id to a non-conflicting ID for these devices based on the information returned in step 2.

5. From the OBP type:

ok nvedit

0: probe-all install-console banner

1: cd /pci@6,4000/scsi@3 *** your path information here ***

2: 6 " scsi-initiator-id" integer-property

3: device-end

4: banner (Ctrl-c)

6. Press Ctrl-c, and store the nvramrc by typing:

ok nvstore

7. Set the system to use the nvramrc and reset auto-boot by typing:

ok setenv use-nvramrc? true

ok setenv auto-boot? true

8. Reset the configuration by typing:

ok reset-all

9. Reboot the hosts. A system reboot is required to implement these changes.

Note - JBOD arrays require a license from VERITAS in order to enable any of its advanced features. Refer to VERITAS Volume Manager Release Notes or contact VERITAS Software Corporation for licensing terms and information.