IBM N3700 A20 Manual

Redpaper
© Copyright IBM Corp. 2007. All rights reserved. ibm.com/redbooks 1
IBM System Storage N3700 A20
Setup
In this IBM Redpaper, we discuss how to set up clustered systems, using IBM®
System Storage™ N3700 Model 2863-A20 as an example. This paper covers:
򐂰Hardware setup, such as cabling and connecting to local area networks
(LANs) and expansion shelves such as the System Storage EXN2000
expansion unit
򐂰Initial setup of the cluster nodes and cluster configuration
򐂰Disk ownership in a clustered environment
We start our planning and installation procedure after unpacking and mounting
the systems in the 19” rack.
Alex Osuna
Dirk Peitzmann

2IBM System Storage N3700 A20 Setup
Planning the implementation
Regardless of whether or not you are installing a single-node or clustered
systems environment, planning and preparation are of particular importance.
Planning and preparation save time during the installation and configuration and
often prevent problems. Gather information and plan before the systems are
installed. Remember, we do not discuss the physical planning and mounting the
appliances and expansions into racks in this IBM Redpaper. You can obtain more
information about those subjects in IBM System Storage N series N3700
Hardware and Service Guide, GA32-0515.
Disk ownership
A System Storage N series cluster consists of two nodes that are able to
takeover/failover their resources or services to the associated counterpart nodes.
This functionality assumes that all resources can be accessed by each node.
That means both nodes must have access to all disks physically (cabling) and
logically (cluster software). The N3700 Model A20 combines both cluster nodes
in one shelf.
Each disk has a preferred ownership and “stays” on the owner node until a
takeover occurs. Ownership can be either to Node A or Node B (Figure 1).
Figure 1 Example disk ownership of Node A and Node B
Shelf 2
Shelf 1
Ownership Node
Ownership Node
A B A B A B A
B A B A B A B
A A B B B A B
A A A B B B A

IBM System Storage N3700 A20 Setup 3
The following table (Table 1) shows a sample disk ownership.
Table 1 Disk ownership sample
Bay number
Disk shelf 1 131211109876543210
NodeAXXXXXXX
NodeBXXXXXXX
Disk shelf 2 131211109876543210
NodeAXXX XXX X
Node B X X X X X X X
Disk shelf 3 131211109876543210
NodeA--------------
NodeB--------------
X marks the node that owns the disk. A dash (-) means no disk in place.
Disks in bay 0 and 1 (shelf 1 and 2) are SCSI Enclosure Services (SES) disks.
Note: Disk ownership is changed after the initial setup, or after adding
additional disks. Use the disk assign command to change ownership, and the
storage disk show command to determine which node owns which disk.

4IBM System Storage N3700 A20 Setup
Check disk assignment after setup using the CLI command storage show disk,
or the Web interface FilerView →Storage →Manage. Figure 2 illustrates disks
in a sample clustered environment.
Figure 2 FilerView: Manage Disks
Setting up the hardware
Now, we describe the installation and setup of the System Storage N3700 Model
A20, the clustered storage system, and the attachment of the System Storage
EXN2000 expansion unit.
Tip: Plan the disk assignment carefully. Load balancing or active/passive
configurations can be reflected in the disk assignment procedure.
Tip: Check the interoperability matrix for supported configurations.

IBM System Storage N3700 A20 Setup 5
Tools and equipment
The N3700 Model A20 shipment package includes:
򐂰N3700 base unit (equipped with two CPU modules)
򐂰Power supplies
򐂰Power cords
򐂰Two console cables (RJ45-DB9) for a serial console
򐂰Fibre channel terminators
򐂰Publications
򐂰Setup kit
򐂰Software licenses
Before you install the hardware, make sure that you already have the appropriate
tools and equipment assembled to use (client-supplied items):
򐂰Flathead screwdriver, and #1 and #2 Phillips head screwdrivers
򐂰Pointed tool (to use for setting termination switches)
򐂰ASCII terminal, console (for example, a notebook computer or PC with serial
port)
򐂰Null modem cable (to connect to the console serial port)
򐂰Ethernet local area network (LAN) cables required for file serving network
򐂰Fibre channel cables for EXN2000 or tape connection (cables to EXN2000
included)
Refer to IBM System Storage N series N3700 Hardware and Service Guide,
GA32-0515, and Installation and Setup Instructions for an System Storage
N3700 and an EXN2000 Expansion Unit, GA32-0517, for more information while
mounting and installing the N3700 filer.
The N3700 Model A20
This section describes the hardware installation of the clustered N3700 Model
A20 storage system. First, we describe the components of the system.
Attention: The N3700 and EXN2000 use sensitive electronic components. To
avoid damage to them, wear an antistatic wrist strap and grounding leash for
the installation.
Note: The N3700 A20 provides two DB-9 to RJ-45 console adapters, one for
each CPU module. You can use this connection to connect a console to the
Filer. Remember to use a null modem cable.

6IBM System Storage N3700 A20 Setup
Components
The N3700 Model A20 filer ships with two power supplies (PSU1 and PSU2),
which are located on the back panel on the rightmost and leftmost sides of the
N3700 appliance. Each power supply has its own ac power cord.
The CPU module Node B is on the middle, bottom of the back panel, module
Node A on the middle, top of the shelf (Figure 3).
Figure 3 N3700 Model A20 back panel
Each of the CPU modules (Figure 4 on page 7) hosts several LEDs and ports.
The ports are:
򐂰Two Ethernet ports (green)
򐂰Console port (purple)
򐂰Two fibre channel ports:
– Fibre channel port 1 (optical, orange) is used for third-party devices (such
as tape for backup).
– Fibre channel port 2 (copper, blue) is used for connections to EXN2000
expansion modules.
Note: We recommend that you use independent, separate power sources.

IBM System Storage N3700 A20 Setup 7
The shelf ID switch and appliance and disk shelf loop switch are between the
CPU modules.
The illustration in Figure 4 shows the CPU module ports. Next, we describe
installing the N3700 cluster.
Figure 4 N3700 CPU module
Connections and cabling
After unpacking and mounting the N3700 and all EXN2000s in a 19” rack, we first
install the base unit (two CPU modules), and then we describe the attachment of
the EXN2000 units. Perform the following steps:
1. Make sure that the N3700 system and its EXN2000 units are turned off.
2. Set the shelf ID of the N3700 base unit to 1 (Figure 5).
Figure 5 Setting the shelf ID
Important: The power to N3700 must be turned off before changing the
shelf ID.

8IBM System Storage N3700 A20 Setup
3. Set the 1Gb/2Gb switch to the 1Gb position (Figure 6).
Figure 6 Setting the 1Gb/2Gb switch
4. Connect the Ethernet cable to the (green) Ethernet port in the middle of the
controller module’s Node A. Repeat this for Node B. See Figure 7 on page 9.
5. Connect the console cables (DB9-RJ45 converter) to the console port
(purple) from Node B and Node A on the back of the appliance (Figure 7 on
page 9). If you are attaching a third-party device, such as a tape backup or a
fibre channel switch, leave the fibre channel ports (orange ports)
un-terminated. Refer to “Connecting to third-party devices” in IBM System
Storage N series N3700 Hardware and Service Guide, GA32-0515, for
details.
1Gb/2Gb Switch

IBM System Storage N3700 A20 Setup 9
6. If no third-party device will be attached to the fibre channel ports (orange
ports), insert the fibre channel terminator or loopback terminator into the fibre
channel ports (orange ports) at the CPU modules (Node A and Node B)
(Figure 7).
Figure 7 Connecting Ethernet, console cables, and fibre channel terminator
7. If an EXN2000 disk shelf will not be attached, set the terminate switch on both
CPU modules (Node B and Node A) to ON (Figure 8).
Figure 8 No EXN2000 attached
If an EXN2000 will not be attached, proceed as follows (system is still off):
a. Plug in the power cord to the left and right power supplies.
b. Fasten the power cords with the hold-down clamps.
c. Plug the other ends of the power cords into the grounded ac power source.
d. Proceed with the initial setup in “Initial configuration” on page 13.

10 IBM System Storage N3700 A20 Setup
8. If you are connecting one or more EXN2000 disk shelves, set the terminate
switch on the CPU modules (Node B and Node A) to OFF (Figure 9).
Figure 9 EXN2000 attached
9. Proceed if you are connecting additional EXN2000 disk shelves. Otherwise,
go to “Initial configuration” on page 13.
If one or more EXN2000s will be attached, proceed as follows (remember,
during the initial hardware setup, the N3700 system is still turned off). Perform
the following steps (Figure 10 on page 11):
a. Confirm that the shelf ID of the base unit is set to 1.
b. Connect the fibre channel port (blue) of Node B (lower CPU module) to the
first EXN2000 disk shelf ESH2 module B (In port).
c. Connect the fibre channel port (blue) of Node A (upper CPU module) to
the first EXN2000 disk shelf ESH2 module A (In port).
d. Attach the grounding cable (EXN2000, base shelf).
Note: The N3700 supports hot plugging a disk shelf. Refer to IBM System
Storage N series N3700 Hardware and Service Guide, GA32-0515, for
details and restrictions.
Attention: The N3700 and the EXN2000 shelves use sensitive electronic
components. To avoid damaging them, put on an antistatic wrist strap and
grounding leash for the installation.