HP StorageWorks Scalable File Share - Manual (Page 338)

Performance figures B–10
B.7 Single client node bandwidth
The graph in Figure B-6 shows the variation of bandwidth available to a single client node as a file is
extended to incorporate additional OST services.
Figure B-6 Single client node, varying number of OST services
These results are based on the following configuration:
• Four SFS20 arrays attached to each Object Storage Server
• Each array populated with twelve 250GB disks, configured as one 2TB LUN with ADG (RAID6)
redundancy (that is, a total of 16 OST LUNs, one LUN on each of the SFS20 arrays)
• Voltaire InfiniBand interconnect
All results are based on tests using new, empty file systems with default MDS and OST mount options and
without quotas enabled.
The client node writes a single file over extra stripes with each data point.
The results show that there is no additional benefit to a single client node of striping over more than eight
OST services. In this configuration, this means the striping is over two Object Storage Servers (there are four
SFS20 arrays attached to each Object Storage Server).
Due to the client side buffer cache being hit by a lot of dirty data, at a setting of 8 OST services, the client
CPU utilization was close to 100%. The CPU utilization is therefore the limiting factor.
Single Client Varying OSTs
0
50
100
150
200
250
300
350
400
450
500
1 2 4 6 8 10 12 16 24
Number of OSTs
M
B
/sec
1 client