VM1 - Delay 90 Seconds
VM2 - Delay 100 Seconds
VM3 - Delay 0 Seconds

The VM3 instead of starting first, always starts last without fail.
One difference I noticed is that VM3 is UEFI vs VM1 & 2 being in BIOS mode.

I read elsewhere in the forum that vApps is the only reliable way to have an order.
Maybe if we can somehow ensure that delay works, vApps will become less significant ?

Would be great for future (of course best tomorrow) to have all the features from VMware vCloud Director regarding Template vApps + API

Just a short compact list:

• Save vApps as templates containing all VMs
• Organize these Templates in Catalogs
• Save Network and Firewall Rules with it (in vCloud DIrectory you can isolate each vApp so be able to really contain same MAC-Addresses identical clones and use a router / fw appliance automatically deployed that uses NAT rules to get into the isolated environments, NSX previous vShield Manager)
  a short youtube video (there might be other better ones but it shows the process): https://www.youtube.com/watch?v=fzoV371vnzs
• be able to use API for automation to deploy vApps and modify network / fw rules

...

• Tenants might be overkill ^^

Two parameters are missing:

• order
• shutdown-delay (In case you need a delay when shutting down. I have no idea if anyone needs this.)

The vApp is created with the following command:

xe appliance-create name-label=name-label [name-description=name-description]

The VMs are added to the vApp with the following command:

xe vm-param-set uuid=VM-UUID appliance=appliance-uuid

Remove from vApp:

xe vm-param-set uuid=VM-UUID appliance=

vApp-Start:

xe appliance-start uuid=appliance-uuid [paused=true|false]

vApp-Stop:

xe appliance-shutdown uuid=appliance-uuid [force=true|false]

If multiple VMs have the same order number, the longest start delay wins before VMs with the next order number are started. The same applies in reverse order for the shutdown-delay when shutting down a vApp.

I'll third the suggestion. There is no other way that I can find to manage startup and shutdown order of VMs which is critical for our infrastructure.

Ups, I was this first here to report the lack of managing vAPPS.

And I second the requirement to include it.
I do not know how else I could manage the start order and start delay of included VMs.

Thanks for your feedback, hopefully, more people or companies are doing the same and tell us!

For all my systems I always create a vAPP, which I call Start.
The start order for all VMs and the time delay are then stored here.
When you shut down, this list is automatically processed in reverse order.

vApps is one of the features I miss most in XenOrchestra.

If necessary, from XCP-ng 8.3 onwards I have to switch to the command line to work with vApps.

We tried to add that, but we've seen little benefit in the end, nobody asked neither, so we dropped it.