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

SFS20 storage — overview and planning 5–27
Table 5-8 shows details of the resulting configuration on two arrays attached to an Object Storage Server
pair (south3 and south4).
5.3.6 Configuring SFS20 arrays in a minimal system
In a minimal system comprised of two servers and two arrays, MDS and OST capabilities are shared by the
same server, and you must create OST LUNs on the arrays in addition to the administration and MDS LUNs.
In such systems, disk groups of eleven 250GB disks are possible with either ADG or RAID5 redundancy. In
the disk group, two LUNs may be configured: a smaller MDS LUN, and a larger OST LUN. This is a typical
configuration for a small system consisting of two servers and two arrays (see Table 5-9). (In the more usual
configuration where OST and MDS LUNs are not located on the same array, any storage beyond the tenth
disk is unused when 250GB disks are used, due to the LUN size limitation of 2TB.) You must configure a
twelfth disk as the spare disk.
The following example shows how to configure the arrays in such a system. In this example, the default ADG
redundancy is used, but you also have the option of specifying RAID5 redundancy:
sfs> configure array 1,2 luns_size=25%,all
Assuming that there are twelve disks in each array, the command in this example configures each array as
follows:
• One disk group of eleven disks, plus one spare disk
• An administration LUN (or spare administration LUN)
• A service LUN (or spare service LUN)
• Two additional LUNs
Because the servers attached to the arrays will run the administration and MDS services, the configure
array command automatically sets the role of the two additional LUNs on each array to mds. You can later
use the set lun command as shown in the following example to change the role of one LUN on each
array from mds to ost:
sfs> set lun 4 role=ost
sfs> set lun 8 role=ost
(You would normally do this as part of the process of creating a file system, as described in Chapter 5 of
the HP StorageWorks Scalable File Share System User Guide.)
Table 5-8 SFS20 arrays attached to Object Storage Servers
Array Disk Group Size Role Connected to Notes
3 11GB service south[3-4] The service LUN for the south3
and south4 server pair.
1 All of the
remaining
capacity in the
disk group to a
maximum of 2TB.
ost south[3-4] The first OST LUN.
4 11GB svcspare south[3-4] A spare service LUN for the south3
and south4 server pair.
1 All of the
remaining
capacity in the
disk group to a
maximum of 2TB.
ost south[3-4] The second OST LUN.