The interesting finding was that when using a 10G NIC there wasn’t a significant reduction in the amount of time it took to clone the VM.
| VAAI OFF | VAAI ON | |
| Start Time | 11:00:28 | 4:26:37 |
| End Time | 11:59:47 | 5:21:15 |
| Total Time | 59m19s | 54m38s |
There was however a significant reduction in network traffic. With VAAI is turned off, a VM it is read to the ESXi host and then written back to the datastore.
Here you can see the amount of network traffic being generated to copy the vApp with VAAI turned off. The peak Data transmit rate is when the VMDK file is being cloned.
Once VAAI is turned on the traffic is near zero as the clone operation is offloaded to the QNAP TS-251b.
The disk is the bottleneck, even though it is a SSD the 10G Network Interface Card can transmit at a speeds of up to 637 MB/s while the disk is only advertised as being capable of 520 MB/s for sequential writes.
Note: Although this photo doesn’t illustrate it the combined read and write speed was close to the advertised speed.
Environment Details
- Dell PowerEdge T440
-
- Two Intel(R) Xeon(R) Gold 5120 CPU @ 2.20GHz
- 512GB RAM
- SAMSUNG 6.4TB NVMe PM1725B PCIe 3.0 X8
- Two Intel(R) Xeon(R) Gold 5120 CPU @ 2.20GHz
- QNAP TS-251B
- Intel® Celeron® J3355 dual-core 2.0 GHz processor
- 8GB RAM
- QNAP Single-Port 10 GbE Network Expansion Card
- Samsung SSD 860 EVO 4TB 2.5 Inch SATA III Internal SSD (MZ-76E4T0B/AM)
- Cisco Catalyst 3560CX-12PD-S Switch
- VMware ESXi 6.7u3
- QNAP-QVAAI_NFS3-3.0-2.vib
Documentation to install the .vib from QNAP is found here