Best External (USB3.0) SSD format to store VMs on

Hi, I have a Macbook Pro 2014, and have an external USB3.0 SSD (Samsung Evo 860 500GB) which I would like to store and run VMs from, using Parallels Desktop 14 Pro from.
I will not transfer the VM files from the external SSD to my Mac. The VM's will be stored on the external SSD, and will always be run from the external SSD.
I do not need any encryption on the SSD, since I know that that will impact performance.

Which is the best MAC OS disk format for external SSDs for such uses, in terms of performance and reliability? Is APFS disk format the best choice for such use scenarios?

 

Hi @clqu the APFS disk is the default format for the newest Mac OS. Performance depends on the special characteristic, which you can check and compare. JFYI lots of Parallels customers use SSD without any issues.

 

Hi Maria, thanks for your reply.
I started configuring the VM, and went to the Hard Disk Options. I tried turning on the Trim Options and a message was displayed stating that the storage device containing the VM file is a non-SSD disk. However, the storage device is actually an SSD (Samsung EVO 860), formatted with APFS with GUID partition map. What can I do so that the external SSD is detected as an SSD?
I also want to extend the disk space of the VM to 400GB (not dynamic expanding), as this tends to improve disk performance. How can I achieve this?

Moreover is there any difference between the SCSI and SATA interface for the VM?

 

Hi Maria, thanks for your reply.
I started configuring the VM, and went to the Hard Disk Options. I tried turning on the Trim Options and a message was displayed stating that the storage device containing the VM file is a non-SSD disk. However, the storage device is actually an SSD (Samsung EVO 860), formatted with APFS with GUID partition map. What can I do so that the external SSD is detected as an SSD?
I also want to extend the disk space of the VM to 400GB (not dynamic expanding), as this tends to improve disk performance. How can I achieve this?

Moreover is there any difference between the SCSI and SATA interface for the VM, such as difference in performance or known issues?

 

@clqu
Hi, I've found this article "Disk Utility does not show APFS format ". Please check and let me know does it help you on not.
If not, I'll do my best to help you with it.

About difference between the SCSI and SATA interface for the VM:
IDE. Using this interface type, you can connect up to 4 virtual devices (hard disks or CD/DVD drives).
SATA. Using this interface type, you can connect up to 6 virtual devices (hard disks or CD/DVD drives).
SCSI. Using this interface type, you can connect up to 15 virtual devices (hard disks or CD/DVD drives).

Note 1: The Mac OS X guest OS does not support the SCSI controller. In the latest Linux distributions, the SCSI driver may be not installed. In this case, you should install this driver in your Linux guest OS to be able to use the SCSI controller.

Note 2: The SCSI 7:0 location is not available for selecting, since it is occupied by the SCSI controller itself.

In order to extend your VM hard drive size, please check https://kb.parallels.com/113972
(Let me know if it's not that case)

Please let me know if you have any additional questions.