Backup performance; HyperV fast, VMware slow; using Synology

[GryphonX77]

So I have a quandary. We are running the latest VB&R, backing up to Synology DS11815+ units using gigabit ethernet. I've setup the NICs on the Synologys to use Link Aggregation, and properly configured it on the connected switch. File transfer is working fine--I can manually copy a file to the NAS as fast as the network allows--basically at full gigabit speed. I realize that they will only take data as fast as it's fed to them--so I will not achieve faster speeds using link aggregation. I was only trying to provide more routes to the NAS.

We have both VMware and HyperV setups backing up to the same NAS. HyperV flies--runs amazingly fast. VMware, not so much. The fastest I've seen is about 54MBps (which is tolerable)--but at times it slows down below 1Mbps...but only on the VMware backups. We've migrated the backup server to a different, dedicated machine. Same results. Any idea why the VMware backups would be so abysmally slow?

Thanks!

[Gostev]

Most likely because you're using Network (nbd) transport mode. For apples to apples comparison with Hyper-V, you should use Direct storage access (san) or Virtual Appliance (hot add) transport modes. Thanks!

[RockemSockem]

The fastest I've seen is about 54MBps (which is tolerable)--but at times it slows down below 1Mbps...but only on the VMware backups.

Tory, are your ESXi vmk interfaces also attached to 1Gb ports? If so, 54MBps is completely reasonable. I forgot where I came across the information, but vmk interfaces will only give ~40% of the available port bandwidth to external API operations. (Don't quote me on the specifics - it was probably a decade or so ago that originally read it.)

If you're looking for better speeds, listen to Anton.

[bdufour]

jumbo frames on your ISCSI network can help on 1ge networks - particularly for backups.

[bdufour]

Also, what are the bottlenecks on these VMware jobs?