[NTLUG:Discuss] Software Raid/Small NAS box ideas

[Darin Smith]

On Sat, 2003-01-25 at 20:06, Kelledin wrote:

> On Saturday 25 January 2003 05:59 pm, Darin Smith wrote:
> > Capability of supporting at least 4 drives, figuring on RAID-4 
> > for redundancy and efficiency of storage volume (though not as
> > performance-happy as mirroring--since it's destined to be
> > networkable filesystems, I see performance as less of an issue)
> 
> First (biggest) flaw: why RAID4?  RAID5 pretty much completely 
> obsoletes RAID3/4, and most any controller that supports RAID4 
> also supports RAID5.  Most modern RAID controllers don't even 
> bother to support RAID3/4 anymore.
> 
> Second: are you planning to do this thru software RAID?  
> RAID3/4/5 takes up a lot of CPU cycles when you do it via 
> software.
> 

I was definitely looking at doing RAID in software.  I had good luck
with software RAID0 and RAID1 in the past.

I figured though, that if mirroring worked that well on a 1.3 Ghz Athlon
running everything plus the kitchen sink (two enet cards, a webcam, a TV
tuner, a webserver, setiathome, the occasional game of Q3A, etc., etc.,
etc.), then a similar box that was only running, say CODA, Samba, a very
low-traffic web-server, in a fairly low-traffic environment (max stress
should be nightly "incremental" backups from my desktop and notebook)
should be able to handle this quite well.  Having heard some "time-sink"
stories with supporting the various hardware RAID controllers out there,
and having had some success with software RAID in the past, I figured,
"why tempt the fates?"  (I don't trust the drivers for the "commodity"
hardware RAID controllers yet).

> > Compact
> 
> Hmmm...exactly how compact?  1u compact? Pizza-box compact?  
> Cigar-box compact?
> 

I was thinking along the lines of the cool little Shuttle box you
mentioned.  I've seen them at Fry's.  Unfortunately, not enough space
for drives.  I've been seeing more drives fail in the past couple of
years than I used to (except for the year 1996, when I was losing a
Western Digital Caviar drive weekly in the lab I ran).  I've seen
Maxtors go, which up until now I had never seen happen.  (My uncle is
still operating a 300MB Maxtor that I bought a LONG time ago...that
thing is ancient, but still going strong).  Thus the reason I wanted to
go with something that would protect me against a single-point drive
hardware failure...So one drive won't work.  Could do RAID1 on 2 drives,
but that seems an awfully inefficient setup in terms of drive space.  3
or more drives seems the better idea.

Shuttle actually has Intel and AMD variants available too...and it looks
as if Alienware is using it as the basis for its "Lan party" machine.

> PC Power & Cooling (http://www.pcpowercooling.com/) produces 
> Sleekline systems that are worth checking out.  Not sure they're 
> cheap enough for you though.  People used to be able to get the 
> Sleekline chassis by itself (1u pizza-box type deal), but that 
> doesn't seem to be possible anymore.  I haven't done any real 
> digging though...
> 

It doesn't have to be pretty, since it will be sitting in my wiring
closet / extra pantry space.  I'm really thinking something like a
mini-tower, but with lots of drive bays.


> And if you absolutely must go even smaller, look into EBX/PC104 
> single-board computers and 2.5" hard drives.  Perhaps even a 
> Cappucino(sp?) bit (like our fearless leader Chris Cox has) 
> would be an option, if you could go with only one drive.  That 
> kind of stuff commands a high price though, and you're likely to 
> have to custom-design the enclosure if you get an EBX board. ;)
> 

Kinda fails the "cheap" requirement.  I've a lot of history with PC104
stuff in my job and a hobby or two I've been involved in, but that's
going to extremes for this kind of project.

> > Does anyone have any opinions on AFS vs. CODA vs. NFS?
> 
> I've found that NFS is generally the best supported across all 
> Unices.  Since you're going to be using Samba anyways, though, 
> you might stick with just SMB--not everything works over SMB, 
> but it's worth a shot...
> 

Somebody on the list mentioned SMB being fastest, but in my experience,
that's only with a Linux box serving it out and a windows box sucking it
up.  Maybe it's a config thing, but I've always had extreme performance
problems with smbmount'ed stuff.  Besides, I expect other Linux boxen to
be the primary users of these shares, so I would rather go with
something that supported *nix permissions better.

NFS is everywhere, but it's been band-aid'ed so much that I'm leery of
it.  Plus, the fact that at one job I worked at the Solaris
implementation was broken and the Linux implementation worked right, and
Sun was slow to acknowledge that their version was wrong--made me lose
faith in Sun as a whole, and made my confidence in NFS sink even lower.

However, I have no experience with either AFS or CODA.  I just know that
they are alternatives.  Since this is for my private home LAN, and will
be firewalled off from the rest of the world, I can go with any of
them.  I just thought maybe someone here has some experience with AFS or
CODA they would like to share.

With storage at less than $1 a gig, I'm wanting to put together
something with 500GB usable space, protected by parity, for under $850. 
I think that should be do'able.  A bonus would be to build it such that
I had the ability to plop down a few hundred later on and get it up to a
cool Terabyte.  Not that I have enough stuff to even half fill the 500GB
yet...still, saying "I have a terrabyte of storage" increases my fellow
engineer's jealosy factor.  Like when I say:
"I have a 65" HDTV." or "My machine has 1.5GB RAM."  Don't ask me...it's
a Dilbertian thing...

Hey, at least it's a (somewhat) cheaper pursuit than collecting classic
cars...though, I might trade quite a bit of my cool techno-stuff for a
fully restored '57 T-bird.  Red, with a black top, please...

--Darin