HP StorageWorks Scalable File Share System Installation and Upgrade Guide Version 2.2
Configuring the storage5–28
Table 5-9 shows an example configuration of a system with two servers and two arrays after the set lun
command has been used to change the LUN roles to ost. In this system configuration, you can create a file
system comprised of one MDS service and four OST services.
5.3.7 Configuring more than one disk group on an array
The information in this section does not apply to arrays where 500GB disks are used.
When 250GB disks or 160GB disks are used, a configuration consisting of two equal-sized disk groups is
also possible, but this is not recommended by HP. This configuration is intended primarily to cater for a
situation where an SFS20 array is initially 50% populated and is subsequently fully populated. This scenario
is not optimal for performance.
The best performance is obtained from a single disk group populated with as many disks as possible.
If there is more than one disk group on an array, the service LUN or spare service LUN is always in the first
disk group (in addition to the MDS or OST LUNs in the disk group).
Table 5-10 shows details of a multiple disk group configuration in a system where 250GB disks are used.
Table 5-9 Minimal system — two servers and two arrays
Array Disk Group Size Role Connected to Notes
1 140GB
1
1. Can be configured to a different size.
adm south[1-2] The administration LUN.
11GB service south[1-2] The service LUN for the south1
and south2 server pair.
125% of the
remaining
capacity in the
disk group.
mds south[1-2] An MDS LUN.
1 All of the
remaining
capacity in the
disk group to a
maximum of 2TB.
ost south[1-2] The first OST LUN.
2 140GB
1
admspare south[1-2] The spare administration LUN.
11GB svcspare south[1-2] A spare service LUN for the south1
and the south2 server pair.
125% of the
remaining
capacity in the
disk group.
mds south[1-2] The second of the pair of LUNs for
the MDS service.
1 All of the
remaining
capacity in the
disk group to a
maximum of 2TB.
ost south[1-2] The second OST LUN.
Table 5-10 SFS20 array — multiple disk group configuration
Redundancy Type Disk Type Number of Disk
Groups
Disk Group
Configuration
LUN Configuration
RAID5 250GB 2 5x250GB disks + 1
spare per disk group
1 X 931GB per disk
group
1
1. 1TB=2
40
; the actual capacity of a 250GB disk is 232GB.
ADG 250GB 2 5x250GB disks + 1
spare per disk group
1 X 698GB per disk
group
1