i'm testing dss v7 with vmware ESXi 5.5 and have a strange situation. At the moment i have only one linux machine on the cluster and the result from harddisk performance is the following:
What are your RAID cache settings?
Have you tweaked the initiator advanced properties to match DSS V7?
===
QueuedCommands=8
DataDigest=None
MaxOutstandingR2T=32
InitialR2T=No
FirstBurstLength=65536
MaxRecvDataSegmentLength=1048576
HeaderDigest=None
MaxXmitDataSegmentLength=1048576
ImmediateData=Yes
MaxBurstLength=1048576
I have a similar issue and from all my testing it points to the replication that causes the performance decrease. I have tried making changes to the replication but cannot improve the performance. I have tested all the 10GB cards using the network test and all tests correct. Eg running iometer replication off /cluster degraded i get RX 1900MBs WR 1800MBs, when cluster normal RX 1250MBs WR 700MBs
Replication can have a impact on performance. This typically can be mitigated by making sure raid caching is working, and is large enough.
In the current releases, the bandwidth is dynamically allocated for each task. This and other tweaks can be done to the replication module: http://kb.open-e.com/Tuning-recommen...1GbE_1603.html (applies to 10GBe also).