Enable support for LUN's "space-allocation" flag

[stang]

trident version: 18.01.0
backend: ontap-san
guest os: ubuntu16.04

We currently can't enable the space-allocation property when a LUN is created.

That option is required in order to allow the host OS to claim back some space (via fstrim for example) when using thin provisioning.

fstrim: FITRIM: Operation not supported

That have multiple consequences:

• as we can't reclaim space, the SAN can't have a wrong information RE the available space on a LUN
• from the SAN POV, the disk usage only increase — when full, the LUN goes offline and partition become readonly in the guest os.
• from the kubernetes perspective, if we try to mount a PV that is link to a LUN that is offlline, it just timeout.

That really limit the usages and can have unexpected impact on a deployment.

[stang]

hi @adkerr - I didn't find any CONTRIBUTE.md: what are the next steps in order to get this PR merged?

[adkerr]

@stang

Thanks for the PR. Next we'll import the commit into our internal CI system and also code review the changes. If we agree with the changes and everything looks good test-wise we'll push it back out automatically. If we need any other updates from you we'll make sure the update the PR on github

[korenaren]

Hi @stang - we've been heads down on some big rock features (Vol Import, CRDs, and other stuff)... sorry this has dragged on. Before we can review your code, we'd need you to sign our Corporate CLA. Is that something you'd be willing to consider? That's the first step. Still not sure what release we are targeting on this one, but can't do anything without the CCLA. I'll send it to you via thePub (Slack). Thanks!

[korenaren]

Added in version 19.07