Hi Guys,
I am looking for some advice as to how to best troubleshoot this problem I am having as I am currently at a loss as to what it can be. I have just finished building an ESXi 5.1 Lab which comprises of:
- Supermicro X7DRH-7F motherboard (10GB onbaord)
- Xeon E5-2620 CPU
- 64GB RAM
- 120GB SSD (planning to use as Host Cache but currently a VMFS volume)
- 16GB Kingston USB Key (ESXi 5 install)
- Synology DS3612xs with an Intel x520 dual 10GB NIC ( 8 X 4TB disks in RAID6, 1 X Samsung 830Pro) Currently using file level iSCSI LUNS
Prior to installing ESXi 5.1 I was running Server 2012. From within Windows connecting to the Synology over iSCSI I would regularly obtain about 200MB/s write speeds over a single 10GB connection (CAT6 cable directly from the 10Gb port on the motherboard to the 10GB port on the Synology). Having installed ESXi 5.1 my write speeds are terrible – about 10MB/s.. This can also be seen when I attempt to take/remove a snapshot as an example.
Initially I though the issue was to do with the networking so I ran through and double checked that the network card, virtual switch and Synology were all configured correctly with an MTU of 9000 and 10GB full duplex which they were (see screenshots).
Conducting some further testing I thought I would attempt to write some files locally to the SSD drive. Logging in locally to the ESXi server using SSH I wrote a file using dd by changing into the appropriate “/vmfs/volumes/blah” where the SSD and Synology iSCSI mount points are. In each instance when using dd (dd if=/dev/urandom of=./TestFile bs=1M count=10) the file write speeds were approximately 10MB/s – which leads me to believe this may not be a network issue.
For clarity I have uploaded a couple of pictures to help with diagnoses:
Hardware and ESXi version info: https://dl.dropboxusercontent.com/u/1428230/ESXi5.1/HardwareInfo.jpg
VM Switch Info (note that the on board NIC is connected directly over CAT6 to the Synology NIC on a different network range to the management and
virtual machine network: https://dl.dropboxusercontent.com/u/1428230/ESXi5.1/Networking.jpg
VM Switch and NIC properties (see MTU of 9000): https://dl.dropboxusercontent.com/u/1428230/ESXi5.1/SwitchNICProperties.jpg
Synology NIC Config: https://dl.dropboxusercontent.com/u/1428230/ESXi5.1/SynologyConfig.jpg
Datastore Info: https://dl.dropboxusercontent.com/u/1428230/ESXi5.1/Storage.jpg
Here is a link to the dd test files and approximate speeds: https://dl.dropboxusercontent.com/u/1428230/ESXi5.1/DDTest.jpg
Appreciate any help with diagnosing this issue or running any additional tests to help out.
Cheers,
Adam