File system level: –> the jfs2 buffers need to be increased (dynamic):

# ioo -p -o j2_dynamicBufferPreallocation=256

service queue_depth on the hdisk devices: –> I would recommend you to increase the service queue_depth from 32 to 48 or to 64. –> please talk to the storage support about this also, as this is not the only LPAR connected to this storage box.

For example, I start with a queue_depth of 32, which is confirmed by looking at lsattr (ODM) and kdb (running config) output:

# lsattr -El hdisk6 -a queue_depth
queue_depth 32 Queue DEPTH True

# echo scsidisk hdisk6 | kdb | grep queue_depth
    ushort queue_depth  = 0x20;        < In Hex.
# echo "ibase=16 ; 20" | bc
          32