Slow iscsi performance on ESXi 6.7.0.
setup 1:-
1) Created a new LUN from ISCSI storage(500 GB) and presented to ESXi hosts.Created a new ISCSI data store and provided 200 GB storage to Windows 2016 OS.
When we are testing the file copy between C to D,we are seeing the transfer rate is below 10 mbps/sec.It starts at 200mbps/sec and going down to below 10 mbps/sec.
setup 2:-
2) When we are passing the direct ISCSI LUN(as a RDM) to Win 2012 OS,we see the transfer rate is more than 1 gbps/sec.
I dont know where is the problem. I like to test the below option to see the performance.
1) First,we need to change the RAID controller in to write cache(enabled) i.e BBRC. If possible,we can insert HBA card to test this.---->Not tested yet.
2) Can be tested by enabling Jumbo frames from Network to Standalone ESXi server/storage server.---->Not tested yet.
3) Can create a new subnet for ISCSI(dedicated) and then can be checked with dedicated NICS.---->Not tested yet.
4) Can change one VM to vmxnet3 and another machine to E1000 and then can be tested.---->Tested but no luck
5) Can change one VMDK to lazy zeroed/eager zeroed and then can be tested---->Tested but no luck
6) Create a new SCSI controller with "Para Virtualization" and then test the performance---->Tested but no luck
Note:- Right now I have 2*10 G NICS for VSAN network.ISCSI also using through the same VSAN network.
Any other suggestions?
Thanks,
Manivel RR