OK. I have done some experiments and am a bit unhappy.
I am going to use the names DISK-S and DISK-M for the two disks which make up the mirror set, the C: or system drive. DISK-S is the original system disk, and I added DISK-M to create the mirror set.
- I can backup the C drive fine (actually is is a backup of DISK-S).
- I cannot restore the C drive as a mirror set directly, I had to remove DISK-M from the mirror and then restore. Then recreate the mirror set. No sweat, but...
- I removed the DISK-S physical disk and found that I cannot boot off DISK-M, I found that in the W7 small print, it says so, so there it is. The mirror is therefore not boot security for failure of the original boot disk. It is only a data source.
I have now removed DISK-M from the mirror set, and left DISK-S on its own, and I can do backup and restores, using the native W7 or Acronis.
My own conclusion: Creating a mirror set for the boot drive is pointless. It yeilds little or no security.
As mirror gives no resistance to messing up your system disk in the first place [mistake, virus, instal something mucky] it can only be useful as a real-time hardware backup. But if you cannot actually boot from both drives, you are stuffed.
I have Googled around, following many threads, and found no reference to anyone actually being able to make the mirror bootable.
I am quite happy to leave my two big 1.5TB disks as a mirror set, as I only want hardware protection, if one fails, no major problems - it is just data, I don't have to boot off them.
This draws a line under this topic for me, hope my findings are of help to some other poor soul.
SF
PS. I built a new W7 system on my old P4 computer to try all this, and then duplicated on my new i7.
i7 x980 3.3Ghz, 12GB, Velociraptor 300, Nvidia GeForce GTX 285, NEC Reference 2690, WD Studio Ed II 2TB