I recently had the joy of adding a RAID1 array to my Ubuntu 13.10 server. I came across a number of problems setting it up, the foremost being the lack of an up-to-date guide for Ubuntu. Most of them, including Ubuntu’s own documentation were woefully out of date.
After several failed attempts, I was able to successfully install a two-drive redundant RAID1 array. Here are the steps I used.
1) Make sure both drives are roughly the same size and installed on the system, your live drive will be /dev/sda for this example and your new drive /dev/sdb. I’d highly recommend backing up /dev/sda before you start.
2) Install mdadm
apt-get install mdadm
3) Download Raider here
4) Install it with the following commands:
cd ~ tar xvfz raider-0.13.2.tar.gz cd raider-0.13.2 ./install.sh
5) Once it’s installed, run raider to erase the new drive, then partition and sync it:
raider --erase sdb raider -R1 sda sdb
6) Ignore any warnings about single user mode and continue. Raider will partition the drive, copy the data over, and configure grub on both drives to use the new array.
7) Shut down the machine, and swap the SATA drive cables to make sda -> sdb and vice versa. Boot the machine, it’ll be booting from the new drive.
7) Once up, run raider again to sync the drives:
8) [NOTE– if the above command worked, you’re already done, this step is not needed] For some reason on my machine raider refused to sync the drives saying “New disk must be connected to the last slot!” nomatter which drive I had in which slot. No problem, you can finish the process manually with mdadm:
Run the command:
/sbin/mdadm --detail /dev/md0
You should get output like the following:
/dev/md0: Version : 1.2 Creation Time : Fri Feb 7 11:35:08 2014 Raid Level : raid1 Array Size : 471741248 (449.89 GiB 483.06 GB) Used Dev Size : 471741248 (449.89 GiB 483.06 GB) Raid Devices : 2 Total Devices : 1 Persistence : Superblock is persistent Update Time : Fri Feb 7 13:05:55 2014 State : clean, degraded Active Devices : 1 Working Devices : 1 Failed Devices : 0 Spare Devices : 0 Name : devserver:0 (local to host devserver) UUID : a55fd0fe:7b142a4c:ad0d9a93:e97e9483 Events : 8834 Number Major Minor RaidDevice State 0 8 17 0 active sync /dev/sdb1 1 0 0 1 removed
This tells use that only 1 of the 2 RAID devices is working: /dev/sdb1. We need to add /dev/sda1 to the array. To do this run:
mdadm /dev/md0 -a /dev/sda1
Running the mdadm detail command will now show the drives are syncing. Give them time to sync up; it could take hours depending on your drives, and reboot. You should now have a redundant RAID1 system. If you want to add more drives, you can with the above mdadm -a command.
This was done on an Ubuntu machine, however the same or similar steps should work on Linux Mint or Debian.