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

Configuring EVA4000 storage 5–13
• Redundancy level.
In an HP SFS system, you must use the RAID5 redundancy level on EVA4000 arrays. The overhead
required to support this level of redundancy reduces the available capacity by a further 20%. For
example, in a disk group where the available capacity is 315GB, using RAID5 redundancy reduces
the available capacity to 252GB.
• Number of virtual disks being created in the disk group.
For example, you may be creating two virtual disks in a disk group, one to be used as a service LUN,
and a second to be used as an OST LUN. The service LUN must be 1GB in size, and this reduces the
capacity available for the OST LUN accordingly.
When creating virtual disks, note the following points:
• On EVA4000 arrays that are assigned to the administration and MDS servers
1
, you must create
virtual disks as follows:
• Create one virtual disk for use as an administration LUN for the entire system.
• For each file system that you plan to create, create two virtual disks for use as MDS LUNs. For
example, if you plan to have two file systems, you must create four MDS LUNs.
• Create one virtual disk for use as a service LUN for the administration and MDS server pair.
• If OST services are run on the administration and MDS servers, create two virtual disks on each
of the arrays for use as OST LUNs.
• On EVA4000 arrays that are assigned to Object Storage Server pairs, you must create virtual disks
as follows:
• Create one virtual disk for use as a service LUN for the Object Storage Server pair.
This virtual disk can be on either of the EVA4000 arrays that are assigned to the Object Storage
Server pair.
• On each of the arrays, create two virtual disks for use as OST LUNs.
To create the virtual disks, perform the following steps:
1. Determine the capacity of each disk group, by entering the command shown in the following example
for each disk group on each array:
sssu> select system HSV01
HSV01> show disk_group “\Disk Groups\Group 1”
.
.
.
\Disk Groups\diskgroup0 information:
Name : \Disk Groups\Group 1
Operational_state : Initialized - Good
Total_disks : 14
Total_capacity : 350GB
Occupancy : 0GB
Occupancy_Alarm_Level : 90 %
Disk_Failure_Protection_Level :
Single
Actual_Protection_Level : Single
Requested_Protection_Level : Single
levelingstate : inactive
levelingprogress : 100
rssdiskstate : mirrored
Comments :
ID : 00010710b40805606500010000d0000000003300
.
.
.
1. In a typical system, there is one dedicated EVA4000 array for the administration and MDS server pair.
On smaller systems where OST services are run on the administration and MDS servers, two EVA4000 arrays are assigned to the
administration and MDS server pair. In this case, the virtual disk that is to be used as the administration LUN must be created on the
array that will normally be accessed by the administration server. The MDS LUNs must be created on the array that will normally be
accessed by the MDS server.