More on this. I remembered that I'd updated the bios for the asus mobo around the time of the raid failure. I'm sure that is what kicked this off.
In the asus bios I found the IDE setting as IDE not RAID like it used to be. I changed it back to raid. Then at boot time I'm offered access to the raid config via ctrl i. That shows the raid system as 'normal' and just as I'd expect it to me. But on continuing with the boot, all I get is ntdlr is missing.
What can I do? I can reboot if I set it back to IDE. Do I rebuilt or remove the existing raid? I don't want to lose those disks, obviously.
You will only get the Intel(R) Matrix Storage Manager installed, if you have either an Intel RAID or AHCI system.
1. Why did your RAID fail and why didn't you repair it by using the RAID Utility?
2. Are you sure, that your SATA hdd's are connected to the Intel (and not to the JMicron) SATA ports?
3. When you are booting, do you see a display about the condition of your RAID array ("failed" or "healthy")?
Maybe you didn't read my posts carefully; that's ok, I appreciate your trying to help.
I am sure now that it failed after I updated the bios for the mobo. RAID was turned off by the update for some reason. I am not able to reenage it so far. If I go into the raid config at boot time, it does say jmicron. But the asus manual refs the intel matrix system, and it used to be an app that reported that raid was ok when I got to windows.
I am not able to get the raid to work again. Inside the boot time raid console the raid array is reported as normal. But after that screen, ntdlr not found. I've set the bios to use raid and raid as the boot priority device, but it still fails at the same point.
1. You may try to repair the BIOS problem by clearing the CMOS memory and to flash the latest BIOS again.
2, If the boot display shows a JMicron RAID and not an Intel RAID, then you have a JMicron one.
3. You have to put that hdd into the first position of the BIOS option "HARD DISK BOOT PRIORITY", where the MBR is. If the RAID device doesn't contain the boot sector, it should not been set on top of the hdd boot order.
I was wrong about the jmicron thing - it's never been on, and the raid utility that I created the array with is the intel one. That array does contain the boot sector; it booted from that array for a couple of years. I guess I will try to re flash.
Am I right in thinking that the jmicron raid is for ext drives only? That's how it's tagged in the asus mobo manual.
This seems to have been solved by unplugging one drive, making the array get marked as degraded, and then plugging it back in and booting. It seems to have rebuilt the array.
Should I now install the newer version of the intel matrix software?