Welcome to the community,
beside continuum opinion ...
If you want to expand existing VD and preserve your data you would need to install OpenManage Server Administrator (OMSA) VIB on ESXi host first.
Then on some Windows machine with access to host management network... download and install Dell OpenManage Server Administrator Managed Node web app.
Run web app on Windows machine connect to desired host ... go to Storage -> PERC XZY Controller -> Virtual Disks and from available task chose "Reconfigure" to expand.
For the latest versions go there:
Dell OpenManage Server Administrator | Dell US