[BozemanLUG] more RAID questions

[Scott Dowdle]

Rob,

----- Original Message -----
> 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?

I read all of that and I understand what you are asking.  I just don't know the answer at the moment as I've only time I've used Linux software RAID it was with RAID 1.

Question:  Please state the make and model of the server.  If it is a Dell box, you can get a hardware RAID card that is Linux compatible for $175 (or at least I did recently for a Dell PowerEdge R510 server with SAS drives).  I know you can use RAID 5 with that and the OS just sees it as one big drive.

You have previously stated you didn't want to go that route... so I'll investigate some and see if I can find you an answer.

TYL,
-- 
Scott Dowdle
704 Church Street
Belgrade, MT 59714
(406)388-0827 [home]
(406)994-3931 [work]