回複：我用RAID的教訓

There are many reasons can cause the RAID failure. like:
-HDD has different firmware
-HDD failure.
-controller failure
-Host improperlly shutdown

But most reason is the PC or server shutdown improperlly.

in your case, degraded RAID 1 should be rebuild automatically, if you sure it turn to 2 RAID 0 your should check the RAID controller BIOS, it may be chenaged by some reason. It may not be your HDD problem.

why you plan to use RAID 0, and convert from RAID 1.
these two is totally different for different usage. 1 for redundancy 0 for performance. and you can not convert from one to another. you need a total system reinstall.