RAID Array Configuration
5. RAID Array Configuration
With hardware assembly out of the way, we now can create the drive array. To do this you need to connect a keyboard, monitor, and power to the computer. Boot up the computer, and when you see the message shown in Figure 8 appear on the screen, hold down
Figure 8: MegaRAID splash screen
I'm going to go through the RAID set up step by step because I found that the biggest stressor in building your own NAS is figuring out the MegaRAID user interface. I stumbled around for several days before getting my first disk array up and running because I could not find any step-by-step instructions. So now there are!
Step 1: Figure 9 shows the MegaRAID Management Menu that will pop up on your screen after you hold down
Figure 9: MegaRAID Management menu
Step 2: Your screen will now appear as in Figure 10. Move the cursor to "New Configuration" and press
Figure 10: Select New Configuration
Step 3: When the "Proceed?" menu pops up (see Figure 11) move the cursor to "Yes" and then hit
Figure 11: Select Yes or No to proceed
The trick is to watch the bottom row of characters on your computer screen. Figure 12 shows the messages that flash by on the bottom row. What is happening here is that your MegaRAID card is scanning the hard drives attached to it.
Figure 12: Status messages
- Previous page Assembly
- Next page RAID Configuration, Continued
An excellent article. I have been trying to setup something like this. I just went thru 2 weeks of trying to get software raid 5 to work in Ubuntu. I searched the net for how-to or step by step instructions and could only find bits and pieces. Nothing worked. Linux users need to remember that us wanna bees don't know even the slightest of commands! In every article I found, they assumed you knew "some" basic commands. I tried reading and learning, but I couldn't find a good learner for linux. Anyway, having decided to do a hardware raid 5 with Ubuntu desktop seemed like my only hope. Then I find this article here, and it is exactly the way EVERY article should be done, step by step, assuming the reader knows nothing. This article is VERY good and thorough! Congratulations Benjamin Webb, you did a great job! -Blueuniform
interesting article, but the beauty of linux software RAID5 is that an array rebuild will happen automatically when you replace the faulty drive (well you have to tell it that you replaced the drive using mdadm). you can even simulate a failure and then watch it rebuild the array to get an idea of how your system will respond under different scenarios. here's a snippet of what needs to be done to replace the missing drive/partition:
Rebuilding:
To remove the failed partition and add the new parition:
mdadm /dev/mdX -r /dev/sdYZ -a /dev/sdYZ
where X is the array number (0,1,etc) and YZ is your disk/partition (sda3 for example)
e.g.:
mdadm /dev/md0 -r /dev/sde3 -a /dev/sdr3
(where sde3 is the 3rd partition on your faulty drive, and sdr3 is the 3rd partition on the new drive)
Watch the automatic reconstruction run with:
watch -n1 cat /proc/mdstat
I understand that people fear the console commands. It can be a bit scary at first. But mdadm is pretty simple when you're used to console apps and a little bit of linux. It's mostly just mdadm and such. I currently run two software raids with 7 and 5 disks.
i believe his concerns with software raid5 were not just the rebuilding points. i believe he liked the fact that if the os drive took a crap, he could take the card and array and move it to any operating computer and it would power up and work. if you lose the operating system that wrote the software raid array, you have lost the array.