[NBLUG/talk] RAID on the cheap?

[Lincoln Peters]

On Tue, 2005-01-11 at 07:05 -0800, Todd Cary wrote:
> I understand your frustration of having HD's fail and the time/work of 
> getting the system back online.  Unfortunately my setup is different 
> from yours in that my RAID is built into the motherboard.  With that 
> difference in mind, I use four drives: one pair for the system and one 
> pair for my data.  These are just RAID 1, but the setup gives me peace 
> of mind.

I now have two software RAID arrays set up: one RAID-1 with two drives
that contains my root filesystem (hence the aforementioned kernel hack),
and one RAID-5 with three drives that contains my /home directory.

I also like the idea of using USB enclosures because if any of the
drives in the USB enclosures fail, I can replace it without having to
unmount the array, turn off my computer, or anything else.  At least
that's the theory; I haven't been using it long enough to test it.

I've heard that it's possible to add drives to a RAID-1, RAID-4, or
RAID-5 array with little fuss, but the version of mdadm I have only
supports this with RAID-1. However, the man page indicates that an
upcoming version may support RAID-4 and RAID-5, and I think it's going
to take me long enough to fill almost 500GB that I can wait.

And, no, my motherboard doesn't have built-in support for RAID.  And
even if it did, I still probably wouldn't use it because I wanted the
external enclosures (to reduce the noise level of the room, I placed
them in a wooden cabinet).

> 
> My production box is Windows (that is what my clients use) and I follow 
> the same setup as on my Linux server (if I do not use a Ghost image, it 
> take 3-5 days to reconfigure my system - that is why I went the RAID 
> route - once was enough).  For this system, I have added a fifth drive 
> that is USB (builtin) with an ExShuttle 2000 just in case I need to 
> access the data from a different computer.  I love those Kingwin 
> pullouts - so convenient.  All of my source code is kept on one and a 
> current Ghost image is kept on another.  Yes, a little paranoid, but I 
> was burned once (actually, twice).

Maybe I should perform more regular backups, in addition to using RAID.
Although I haven't gotten burned by not having backups, at least not
since I placed my home directory on its own hard disk (or on its own
RAID array).  I should never forget Murphy's Law.

> 
> Of course now that I have everything RAID'd, the disks have not failed - 
> isn't that the usual situation?!?.

It may be the contrapositive of Murphy's Law: whatever *can't* go wrong
*won't* go wrong...or something like that.  In other words, as long as
we have everything RAID'd, the disks will work perfectly until the end
of time.

---
Lincoln Peters
<sampln at sbcglobal.net>

We are anthill men upon an anthill world.
		-- Ray Bradbury