Read slower than write - help me find the bottleneck

[hoba]

Hi,

I think this sounds pretty familiar to the problems I'm seeing too ( see https://forums.starwindsoftware.com/vie ... 975#p26975 ). I hope the solution that you come up with will help me too. Even the used hardware seems to be pretty similiar. If I can help with testing or you need another system for comparism, let me know. I'm happy to help out.

Regards,
Holger

[Sergey (staff)]

Hello, Holger! Yes, your case is very similar to this one. In dfirs case, RAID5 SSD drives are used as underlying storage, and the bottleneck is one 10Gb/s network interface used for the iSCSI connection. We have advised adding 1 more 10Gb network interface. According to test results, 1.2GB/s write speed has been achieved, which equals 10Gb/s network bandwidth. Also, there is just 1 storage node used. If you add 1 more storage node, you can potentially gain about 30-50% read performance boost.
It makes sense to run performance test at 2 VMs (located on the StarWind device) at the same time.
Also, take into account that StarWind adds virtualization layer to existing ESXi infrastructure, so 10-15% performance difference is considered acceptable.