[BozemanLUG] more RAID questions

[R. Potter]

OK, I have some more questions.  All the instructions I find on line 
always tell you the instructions will work for all RAID's but then they 
only use RAID 1 as the base for the instructions.

As I studied my space needs, I decided I needed to maximize.  Originally 
I was going to stripe two sets of 1 TB drives and then RAID 1 the two 
striped sets.  But this would only give me 2 TB of storage.  Nothing to 
sneeze at, but at first glance RAID 5 would give me 3 TB (4 x 1 TB).

So I started following the instructions which is when I think I hit a 
snag.  the instructions have you create a new partition - the first of 
which is the SWAP.  Then the next partition is set as boot-able and ext 
4 file system.  This configuration makes perfect since if using RAID 0 
or 1, but from what I can tell this won't work for RAID 5.

I have also seen some indication in the instructions I have found that 
say boot-able cannot be RAID 5.  Some say you cannot have RAID 5 OS but 
others imply that you can.

So my first question is can I have the OS, SWAP, and data storage under 
RAID 5?  If so, how do I configure this?  With RAID 1 I would duplicate 
the SWAP and boot-able partition but that does not make sense under RAID 5.

This server box can hold 4 drives and each drive is only allowed to be 
no bigger than 1 TB in size.  So, setting up a solo drive for the OS 
will cost me drive space and will prevent redundancy of the installed 
OS.  If I have two drives dedicated to the OS running RAID 1 then I lose 
even more needed space.

So the way I look at it, either I am missing something for setting up 
RAID 5, or my only option for redundancy and max space is stripping two 
sets of two 1TB drives then mirroring the two sets.  Is this my only option?

Rob Potter