Will Creating a Raid 1 Array Wipe the Original Drive?

Will creating a RAID 1 array wipe the original drive, or will it just get mirrored?

Nope! I’ve built many Linux RAID1 storage using most of the popular RAID controller cards (I won’t mention names or t’ll come after me for blasphemy). In my own tests, native Linux mdadm RAID1 with SATA drives directly on the motherboard outperforms 3rd party hardware controllers. Yeah. Don’t ask me why. My controller card caches were set to write-back (no iowait) and had battery backup to write unfinished I/O to disk if power was cut. Battery backup is the only positive for the 3rd party cards. In almost all instances, it was much better performance to just do RAID1 directly in Linux. That means for every write, the OS writes to X drives in parallel. Management is easier in Linux than through the typical controller card firmware. You can automate monitoring your RAID status by looking at one status file. Here you can see I have 1 failed drive in one of my 4-way RAID1 sets. But who cares? I’ll wait til 1 more dies before I replace. Or if I feel lucky, I’ll wait til 3 die. [root@linuxbox ~]# cat /proc/mdstat Personalities . [raid1] md8 . active raid1 sdd2[3](F) sdc2[2] sdb2[1] sda2[0] 8193024 blocks [4/3] [UUU_] md9 . active raid1 sdd1[3] sdc1[2] sdb1[1] sda1[0] 65537024 blocks [4/4] [UUUU] unused devices. Also, creating RAID sets is much easier in Linux. Need a 4-way RAID1 on four drives? You’ll need to use fdisk (<4tb) or gparted (>4tb) to create partitions first. But other than that, it’s one command. mdadm --create /dev/md0 --level=1 --raid-devices=4 /dev/sda1 /dev/sdb1 /dev/sdc1 /dev/sdd1 P.S. You might wonder why I don’t talk about LVM instead of mdadm. LVM is just crazy overkill for home use. Unless you need to resize volumes on the fly or take live point-in-time snapshots for backups, mdadm is my choice. P.P.S. Why do I not run RAID5? Wouldn’t I save money and have more disk space? Yes, but hard drives are cheap. Is it worth an extra $100–200 in hard drives to have quadruple redundancy for your entire life worth of personal files and photos? It is to me.