On 6/23/2012 12:15 AM, Digimer wrote:
Software RAID? If you have two or more disks, yes.
There's no requirement that if you have two disks, they have to be RAIDed together. I frequently build systems with /dev/sda being a lone SATA disk for the OS and apps, with /dev/sdb being a hardware RAID for the real data the system manages. Another pattern I've used is a small CF card for the core OS, and /usr, /home and other bulk users of storage off on a second spinning disk.
A better test is probably "mount | grep md".
Then there's the LVM option, but I can't immediately come up with a one-liner that tells you whether a given LVM disk set is equivalent to software RAID.
And then we can get into more exotic options like btrfs and zfs which are also potentially RAID-like, but not necessarily so.