Just install SSD drives on my ESXI Hosts and configured VSAN.
After claiming the drive on 4 hosts
The VSANDatastore was created on all the hosts but has Zero space available
Any reason why ??
Please read and understand what I said:
"You still haven't indicated if you are even using Jumbo frames (9000 MTU) which I did ask twice, so the above isn't actually an indication of whether you have an issue with MTU mismatch.
Check what MTU is actually configured on the problem node(s) with:
# esxcfg-nics -l
# esxcfg-vmknic -l
# esxcfg-vswitch -l
If it is 1500 throughout then you are not using Jumbo frames and should be testing connectivity (e.g. from node TGCSESXI-9) using:
# vmkping -I vmk2 -s 1472 -d 10.2.8.62
I did not tell you to make random changes to the MTU in your environment but merely to confirm what MTU you had intended to be configured and was supported by the environment - just an FYI, making the same changes you made in a functional 1500 MTU environment would likely cause a full vSAN network outage.
This is why daphnissov said you need to check it "end-to-end" he meant you need to confirm (and understand the implications of) the MTU supported and configured in the environment.
Think of it this way: having MTU set to 9000 on the vmk/vswitch but only 1500 supported/configured on the physical switch(es) the packets are going to be fragmented and it won't work in any stable manner. Conversely if you had 1500 set on the vmk/vswitch but 9000 on the physical switch(es) there would be no issue as 1500 bytes packages can fit in this with no issues. You look to have configured the former here (as you still can't send large packets) - if you aren't aware/sure of what the switch settings are then configure everything as 1500 and test whether the network is stable (e.g. vmkping vmkX -s 1472 -d -i 0.1 -c 100 <Dest-IP>).
Also, please stop replying to the same answers for the same problem in 2 different threads - this is pointless and only adds to the confusion - I would strongly advise you read the links from daphnissov signature, it should really help you help yourself (and not just when asking strangers for help on the internet but also when approaching problems and how to scope and progress issues productively.
Edit: corrected command syntax
This is crazy and upsetting,
I changed the MTU to 9000 on my Cisco switch where all the ESXI hosts are connected.
After reloading the switch to my surprise the VSANDatastore had 6.8 TB of disk space.
When I come home to check the ESXI hosts and there datastores it was still there. Great news
I went out for dinner and when I came back got back on and now there are a ZERO again.
What is up with this?
Have you read one word of what TheBobkin has told you? You certainly don't seem to have despite his (and my) best efforts. You really need to back-track through this post (and your, for whatever reason, duplicate post) and validate the things that have been asked of you. If you're not going to take the advice and provide the information requested, we cannot help you here. So I'm out of this one...
So why would it disappear then come back?
Probably because you have configured something wrong and/or because your hardware is not supported for ESXi 6.5 and vSAN 6.5/6.6... This can lead to unpredictable and weird behavior.
But the others have already written this in several posts and you are either unwilling to understand or you lack the technical understanding to implement these suggestions. So, how should we help you? You can write as often as you want that it doesn't work, but that way you won't solve the problem and it's not clear if it can be solved at all (because the hardware isn't supported).
Looks like it is holding steady now.
On the Cluster I I have this message
VSAN Health Alarm ESXI-VSAN SERVICE Installation
I can reset it to green but is there something I can check.,