Volume creation succeeds on a datastore which is in maintenance mode

[ashahi1]

Steps:

1. Created a datastore cluster of two datastores - sharedVmfs-1 and sharedVmfs-0
2. Put sharedVmfs-1 in 'Maintenance Mode'
3. Then was able to create volume to the datastore  - sharedVmfs-1
4. Successfully mounted the volume to a container and was also able to write data to it.

This should not be allowed. Volume creation should not succeed on datastore which is in maintenance mode as user may have put it in maintenance mode to perform some service on it or user may even decide to drop the datastore completely which is in maintenance mode.

Logs have been attached at the end.

---

Steps and their output are as follows:

1. Create a volume

root@sc-rdops-vm02-dhcp-52-237:~# docker volume create -d vsphere:latest --name TestVolMM@sharedVmfs-1
TestVolMM@sharedVmfs-1
root@sc-rdops-vm02-dhcp-52-237:~#
root@sc-rdops-vm02-dhcp-52-237:~#
root@sc-rdops-vm02-dhcp-52-237:~# docker volume ls
DRIVER              VOLUME NAME
vsphere:latest      TestVolMM@sharedVmfs-1
vsphere:latest      TestVolSS@sharedVmfs-0
vsphere:latest      VolSS1@sharedVmfs-0
root@sc-rdops-vm02-dhcp-52-237:~#

2. Docker volume inspect

root@sc-rdops-vm02-dhcp-52-237:~# docker volume inspect TestVolMM@sharedVmfs-1
[
    {
        "Driver": "vsphere:latest",
        "Labels": {},
        "Mountpoint": "/mnt/vmdk/TestVolMM@sharedVmfs-1",
        "Name": "TestVolMM@sharedVmfs-1",
        "Options": {},
        "Scope": "global",
        "Status": {
            "access": "read-write",
            "attach-as": "independent_persistent",
            "capacity": {
                "allocated": "13MB",
                "size": "100MB"
            },
            "clone-from": "None",
            "created": "Thu Jul 27 19:30:13 2017",
            "created by VM": "ubuntu-VM0.1",
            "datastore": "sharedVmfs-1",
            "diskformat": "thin",
            "fstype": "ext4",
            "status": "detached"
        }
    }
]

3. Mount the volume to a container and write some data

root@sc-rdops-vm02-dhcp-52-237:~# docker run -it --volume-driver=vsphere:latest -v TestVolMM@sharedVmfs-1:/vol1 --name ubMM ubuntu
root@0a16291ffec1:/#
root@0a16291ffec1:/# echo "Hello" > vol1/hellos2
root@0a16291ffec1:/# cat vol1/hellos2
Hello
root@0a16291ffec1:/#

Logs:
docker-volume-vsphere.txt
vmdk_ops.txt

[lipingxue]

@ashahi1 Can we create and attach VMDK to VM using ESXi UI when the datastore is in maintenance mode?

[ashahi1]

@lipingxue I tried from VC but I am not able to create VM on a datastore which is in maintenance mode. That particular datastore is not listed among available datastore for vm creation. Datastore maintenance mode is a VC feature.
Also, there is no event generated in hostd logs when datastore is put in maintenance mode. So it looks like ESX side is unaware of datastore maintenance mode.

Dockvols folder on datatore which is in maintenance mode, does show created vmdk.

[lipingxue]

@ashahi1 Since esx is not aware of datastore in maintenance mode, and still can create vmdk on the datastore, no fix can be done. We should document it as known issue.

[shuklanirdesh82]

@ashahi1 as discussed offline please include this into the same PR where you are adding information for inter-op features.

[ashahi1]

Fixed as part of PR #1689