Apple Xsan 2 - Manual (Page 44)

Important: If you create users and groups on each SAN computer, be sure that:
Each user or group has a numeric user ID (UID) or group ID (GID) that is unique Â
throughout the SAN
Each user or group defined on more than one computer has the same UID or GID
Â
on each computer
Outgoing mail service
Xsan can send SAN status notifications via email on your local network (IP subnet)
without using a separate mail server. However, depending on your network
configuration, you may need an SMTP server to send notifications outside your
local network.
If you don’t have access to an outgoing mail server, use the mail service in Mac OS X Lion
Server to set one up. For information, open the Server app and search Server Help.
Plan your SAN
It’s easy to add storage to an Xsan SAN, but reorganizing a SAN after you set it up
isn’t simple. So, it’s important to plan the layout and organization of your SAN and its
storage before you set it up.
An Xsan SAN is made up of:
Storage devices (RAID systems) Â
LUNs (SCSI logical unit numbers, usually RAID arrays) Â
Storage pools (groups of LUNs) Â
Affinity tags, which identify storage pools with similar performance and data protection Â
Volumes (groups of storage pools visible to users) Â
Clients (computers that use volumes) Â
Controllers (computers that manage volume metadata) Â
An Ethernet network used to exchange volume metadata Â
A Fibre Channel network used to transfer data to and from volumes Â
Before you set up a SAN, you must decide how to organize these components. Take
the time to create a diagram or a table that organizes available hardware into RAID
arrays, volumes, client computers, and metadata controllers in a way that meets SAN
users’ needs and your needs as the SAN administrator.
You don’t need to plan storage pools or affinity tags if you set up each volume using a
preset volume type based on the kind of work the volume supports.
44 Chapter 3 Plan a SAN