[SOLVED] Software Raid5 adding new disk

zer0signal · 08-25-2011, 10:19 PM

Hi guys,

Just a quick question, I have searched around on Google, but am having a hard time coming up with the answer I am looking for. If you could just shoot it to me straight I would appreciate it.

I am building a 4 x 2TB Raid 5 software array in Redhat, before i start this array I wanted to know if at some point in the future I can add a New Disk to the array and go from 4 to 5 disk's and not loose everything? As in start the array over from scratch?

I did see on some legacy pages I found from 2k6 that it was only possible with Raid 1, but need to know if this works with 5?

My goal is to just extend the LV once the new disk is in the array...

mesiol · 08-25-2011, 11:24 PM

mdadm man page says

Code:

Grow  (or  shrink)  an array, or otherwise reshape it in some way.  Currently supported growth
      options include changing the active size of component  devices  and  changing  the  number  of
      active devices in RAID levels 1/4/5/6, as well as adding or removing a write-intent bitmap.

but i have no experience using this option. Also this is a very time consuming job on RAID-5. All data has to be redistributed to all disks, and i'm not sure what state the array has in case of failure during this relocation.

zer0signal · 08-25-2011, 11:29 PM

thanks, i dont know why i did not think to look through the man pages.. =/ 1st mistake on my part, but i will run the risk. I will build it and when time comes back it up to tape as a fail safe before the grow.