Use entire disk or img file?

[WebGuy]

I have a 2 tb drive for backups. Would it be faster to use the entire disk as a ISCSI target, or to create a img file for the ISCSI target? Seems like using the entire disk would be but I wanted to ask the experts. Trying to get the fastest access possible.

Thanks!

[Olivia (staff)]

The image device has a little better performance than the physical disk device, not obviously.
Image device is recommend for mirroring because it can be easily migrated and restored, use physical disk as mirror device will bring a little flexible, but please be sure to choose "Persistent exlusive access on this device" option, because any modification directly to the device at the server side will cause an data inconsistence between the two mirror devices.