Create RAID Array from disk manager LM11-12

[akd]

Here's my problem: in "disk manager"->File->create->raid array I should be able to create a software raid array, am I right?

But I can't figure out how to do it: I have the boot disk and 2 other disks formatted in a 500 gb partition ext4. All disks are 500 gb.

The only disk I can select to build the raid array is the system one: the other 2 are "gray" and not selectable. This happened in LM 11.

I then tried LM 12 in vmware, to play with disks freely. In this case the only selectable disk was the non-system one, and only before formatting in one single ext4 partition as well.

I really can't understand what to do to create an easy RAID 1 array between the system disk and a free one, and then manage and monitor (and in case rebuild the array).
It seemed to be as easy as in windows, where with just 5-6 clicks you have a working array, but I can always see just one available disk a time...

Could anybody help please?

[remoulder]

See http://blog.rogersoles.com/technology/u ... -creation/ and http://superuser.com/questions/230497/u ... id-1-array amongst others.

[akd]

Thank you very much, but it's not exactly what I need: I'd like to include the OS disk in the raid array, without reinstalling the OS, if possible.

I'd like to understand why there is the chance to create a new raid configuration with a few clicks, and then you just can't: how is required the disk to be formatted, to do this?

[remoulder]

and then you just can't

Did you actually read the links I gave you? The first one mentions you have to have mdadm installed before you can use disk utility.

[akd]

Yes, I did read them. If I'm not mistaken, the second one talks about create an array between two non-os disks, and the first one (I quote)

In Disk Utility, just access “File->Create->Raid Array…” on the menu and choose the options. Before doing that, you might want to clear off the drives you’re going to use (I generally create a fresh GTP partition to insure the drive is ready to be used as a component of the RAID array).

Apparently I have to erase disks I'm going to use with a new partition, and I can't obviously do that with a system disk...

By the way, I have mdadm installed, althought maybe I'm not so good with it.