Vsan Slow Sync

[koittech01]

Attached screenshot.
Why is the sync so slow for vsan?

I have a 2node Dell 2950 using 3 NICs, 1Gbps each.
1 management - switch
1 heartbeat - cross over cable
1 synch & heartbeat - cross over cable

Each time i reboot or shutdown a node, it has to do a sync and shows 1-2 hours to complete sync.

[Ivan (staff)]

Hello koittech01,
Thanks for your interest in StarWind solution.
Could you please provide us more information about your environment?
I would more than happy if you will share with us Type of disks (HDD or SSD), RPM (if spindle) and size of StarWind device which is synchronizing.
Also, size and mode of L1 cache and version of StarWind vSAN

[koittech01]

Thanks for reply Ivan,
I'm pretty much at page 37 in the hyperconverged 2node setup hyper-v cluster guide.

StarWind Mangement Console for Windows: v8.0.0.11156

2 Dell 2950s
On each server:
2x 300GB 10K RPM C: drive
1x 1TB 7.2k RPM E: drive

Created 2 Starwind devices (.img) at 200GB each, for total of 400GB on the 1TB E: drive.
Plus 1GB Witness image
All disks replicated to node2

Cache:
Mode: Write-Back
Size: 128 MB
Usage % 0
Hits, % 91

[Ivan (staff)]

Hello koittech01,
It looks like your slow synchronization speed limited by 1 Gb Synchronization channel or 7,2K RPM drive performance
Maximum data transfer speed on 1 Gb channel is ~100 MB/s which means that maximum data transfer can be around 280 GB/hour.
Regarding the full sync after every restart. Please make sure that Windows as well as StarWind service stopping properly during restart. Also, you can try to remove 128 MB WB cache and avoid full sync in future. You can find the instruction how to properly remove L1 cache from StarWind devices by following next KB article:https://knowledgebase.starwindsoftware. ... -l1-cache/