On 08/18/2017 11:56 AM, ToddAndMargo wrote:
>  > On 8/18/2017 1:46 PM, ToddAndMargo wrote:>> Hi All,
>  >>
>  >> Is there a way to create software raid 1 after the fact?
>  >> Meaning, you already installed SL on a stand alone drive.
>  >>
>  >> -T
>  >
> 
> On 08/18/2017 11:44 AM, Betts, Wayne wrote:
>> Hello T,
>>
>> I have successfully used a utility called Raider a couple of times: 
>> http://raider.sourceforge.net/  It is proof that what you want to do 
>> can be done.  Read the README, which is not terribly long.  I don't 
>> remember the details of the systems used it on, but I recall being 
>> impressed at the details it handled.  Everything it does can be done 
>> by hand with various core utilities (which is what raider uses anyway) 
>> and it isn't terribly hard to understand, but Raider handles a lot of 
>> the details automatically, making the process less error-prone than 
>> trying to go through everything by hand.
>>
>> While it is possible to use Raider on a live, fully functioning system 
>> to minimize downtime (other than a necessary reboot), you can and 
>> often should run Raider in single-user mode.  There is a power down to 
>> physically swap disks and boot from the new degraded array(s), after 
>> which the new RAID array(s) begin syncing.
>>
>> Of course, it is strongly recommended that you first clone the disk 
>> (or at least make a remote backup of any important files) with a 
>> utility you trust and are familiar with.  (I often use Clonezilla, but 
>> there are a lot of options for this.)
>>
>> -Wayne
> 
> 
> Thank you!


In case anyone is wondering, to get your status:

     # cat /proc/mdstat

Look for "U"'s to make sure each drive is "up"