HP StorageWorks Scalable File Share System Installation and Upgrade Guide Version 2.2

EVA4000 storage — overview and planning 5–5
Administration LUN
The administration LUN is used to store configuration information for the HP SFS system. There is
only one administration LUN for the whole system, and it must be created on the EVA4000 array
that is connected to the administration and MDS servers.
In the HP SFS user interface, the administration LUN is identified as the adm LUN.
Service LUN
Service LUNs are used to store management data and control data for a pair of servers.
There is one service LUN for each server pair. In the HP SFS user interface, a service LUN is
identified as a service LUN.
5.1.3.2 Assigning and sizing LUNs on EVA4000 storage — examples
This section provides examples of the number, size, and type of LUNs that would be needed for systems of
various sizes and configurations. Each example describes a different possible configuration of the MDS
server—specifically, whether a server is dedicated to MDS services or whether it also runs OST services.
Use these examples to help you to plan your system configuration, and record the details of your system on
the worksheet provided in Table B-8 in Appendix B.
The examples are presented in tables, and for each LUN, the following information is specified in the table:
Array
The EVA4000 array that the LUN is on. Note that the array numbers shown here are examples
only. The HP SFS system may assign a different number to the array. Use the WWID to uniquely
identify an array.
Disk group
The disk group that the LUN is in.
Size
The size of the LUN. The following rules determine the size of the LUNs:
• The recommended size of the administration LUN is 40GB. The minimum required size is
10GB.
The size of the administration LUN determines the amount of performance data that can be
gathered and retained for viewing and analysis. As a guide to determining a suitable size
for the administration LUN in your system, allow 20MB per day per server for the number
of days you want to retain performance data, plus an additional 4GB.
For example, in a system that has 16 servers (14 Object Storage Servers, an administration
server, and an MDS server), where data is to be retained for 30 days, the size of the
administration LUN would be calculated as:
(30 * 20 * 16)MB + 4GB=13.6GB (rounded up to 14GB)
(Refer to Chapter 4 of the HP StorageWorks Scalable File Share System User Guide for
information on gathering performance data using the collectl utility.)
• Service LUNs are fixed size.
• The size of MDS LUNs depends on whether there is one or multiple file systems and
whether there will also be an OST LUN in the same disk group. If multiple MDS or OST
LUNs compete for available capacity, you may need to balance the sizes carefully. See
Section 5.5 for information on sizing the MDS LUN.