We recently had a Problem with the Raid Card in our Windows Server. We used this excuse to enlarge our storage Pool and implement a few other upgrades.
The current Setup is:
- FreeNAS Server
The Server used is a Dell Poweredge R710 with dual Quad Core Xeon and 32 GB Ram. We intend to Upgrade to 64 GB in the near future. HDDs are 10x WD RED 4TB. They are connected to the server with an LSI SAS 9201-16e. The FreeNAS Server should be connected to a Windows Server with two parallel 10Gbps connections. The Cards used are Mellanox MNPH29D-XTR in both the FreeNAS Server and the Windows Server.
- Windows Server
The Windows Server is a HP Proliant DL380 G7 with two hexa core Xeon CPUs. This server should manage the iSCSI share of the FreeNAS and assign user permissions.
Our Problem is the following. When I connect one iSCSI connection in windows I get the following speed test Results (looking only at sequential read and write):
Sequential Read (Q= 32,T= 1) : 1180.009 MB/s
Sequential Write (Q= 32,T= 1) : 880.378 MB/s
Wen I connect a second iSCSI connection and tell windows it is looking at the same storage pool, I get the following result:
Sequential Read (Q= 32,T= 1) : 1613.847 MB/s
Sequential Write (Q= 32,T= 1) : 542.431 MB/s
The read speed is close to the maximum speed of the drive array. With ZFS tuning I got close. What irritates me, and what I do not understand is why the write speed went down. I made no changes to the FreeNAS system in between these tests.
Does anyone have any ideas? what could I try? am I fundamentally misunderstanding MPIO and expecting something that shouldn't work?
Thanks for your help.