VM and sleeping LUN

[NMe]

Hello,
I built a VM (W7 Home x32) on an host (W7 Ultm x64). Virtualbox is 5.0.16. Three drives are defined for the VM : its own drive, a shared drive with the host, and a LUN drive on a target somewhere in the LAN. All work correctly. But, after a few hours without any exchange - typically during the night - the NAS on which is the LUN gets to sleep. Then, the VM freezes and must be closed and restarted.
Before I stop NAS sleeping function - easy, but energy consumer -, do you have any idea to keep the VM alive ?
Thank you.
NMe

[mpack]

Can you clarify what a "LUN drive on a target somwhere in the LAN" means? It sounds like you just mean (or should just mean) a VDI located on a network share?

If it's just a VDI located on a network share then I'd expect the NAS to wake up when the VMs host tries to access the VDI file. You might want to turn off I/O caching on that drive (in VM settings | Storage), just in case the asynch access is causing the problem.

If you meant something else then please explain.

[scottgus1]

the NAS on which is the LUN gets to sleep. Then, the VM freezes and must be closed and restarted.

I'm guessing the LUN thing means that the guest believes it has a real drive on one of its ports even though the drive file exists on the NAS through the network. Having the NAS go to sleep is the equivalent of yanking a physical SATA cable off a physical drive while a physical computer is running. If the OS hasn't set the drive up as hot-swappable, the OS may crash.

Gotta keep the NAS up, or use a shared folder instead of that LUN drive.