Design considerations - 2 datacenters

[CaseBlue]

Hi all,

I have a question concerning recommended design considerations when stretching the storage nodes between 2 datacenters.

The end-goal is to have 2 separate storage-servers who are a exact copy of eachother. I'm not entirely sure yet how starwind interacts with VMware on a iSCSI target level, yet. Any input here appreciated.

2 ESX servers, 2 storage servers, as far as storage is concerned: 2 dedicated 10 gig circuits between them. See diagram enclosed.

I have a few questions.

1. The data synchronisation between the 2 sites, do you recommend using 1 path or 2 path as active/active? RTT on both links may vary a few milliseconds. I don't have exact figures (yet), but generally it should all be below 5ms.

Is there a problem with this setup in general? We are not counting on starwind for backup, but we are using it merely as a storage replication for high availability.

Any input is welcome, I will add more details next week when I actually have access to this setup in person.

[yaroslav (staff)]

Hi,
Thank you for your questions! StarWind VSAN is not a backup solution.
Here are some thoughts on your setup.
Please make sure the latency to be dub 5ms and use redundant networking between the datacentres.
Dedicated (i.e., not used for anything else) links are the must for iSCSI and Sync. In other words, nothing should be going over iSCSi link but iSCSI and nothing but synchronization over synchronization.
Useful readout:
System requirements https://www.starwindsoftware.com/system-requirements
Split-brain, and how avoid it https://www.starwindsoftware.com/blog/w ... o-avoid-it if you are 100% sure the networking redundancy is met (i.e., at least two independent links between locations and redundant NICs in the servers), go with Heartbeat failover strategy.
Your targets can be visible over iSCSi to both hosts. See for the reference these guides https://www.starwindsoftware.com/resour ... phere-6-0/ and https://www.starwindsoftware.com/resour ... r-vsphere/.