Can I boot from a software RAID5 setup with linux?

Question

I am planning the setup of a new NAS system, deciding if using Openfiler or something similar.

I've been checking some RAID cards, and thinking about hardware failure or substitution, and I have the doubt if I could make a system boot directly from a software RAID5, without having to boot from another volume first.

That would give me the flexibility of substituting my hardware in case of any fail without problems, knowing that the software is handling my RAID and I'm not dependent on any brand or model in particular...

Answer 1

Yes, with a slight modification.

Partition your disks into two Linux Raid partitions - one 128MB partition for /boot and the rest for RAID5.

Then use software RAID1 to mirror all the small 128MB partitions.

You'll end up with something like:

michael@baron:~$ cat /proc/mdstat 
Personalities : [raid1] [raid10] 
md0 : active raid1 sda1[0] sdd1[3] sdc1[2] sdb1[1]
      136448 blocks [4/4] [UUUU]

md1 : active raid10 sda2[0] sdd2[3] sdc2[2] sdb2[1]
      143090816 blocks 64K chunks 2 near-copies [4/4] [UUUU]