[XCSSA] Recommendations for a SAMBA/NAS device?

[X-otic Computer Systems of San Antonio]

On Thursday 21 May 2009 05:39:20 pm X-otic Computer Systems of San Antonio 
wrote:
[...]
>
> Aha! The truth comes out! 

Yeah.. Tweeks is a closet SW-RAID geek. :)  What can I say.. I'm cheap. :)


> I've only done SW RAID1. I try to avoid 
> RAID5 as much as possible, although you bring up a good point that I
> want to make sure I understand. Are you suggesting not to run SW RAID5
> on /? Or are you suggesting to avoid using the same CPU that runs the
> system to also perform the RAID5 calculations?

Yes!
Well.. both anyway. :)

So never run software RAID-5 on the / system.. (processor affinity or none). 
But yes.. SW-RAID-5 on / is bad juju. If you try to boot a RAID-5 system that 
is degraded.. I've literally seen it take 45 minutes to to boot the system.  
During which time you're at high risk of losing everything if there are ANY 
system hiccups.  And if it does hiccup or go down.. the filesystem can easily 
be corrupted and data loss.

Now.. that being said.. Offering out software RAID-5 from on another system 
(such as a NAS box, SAN, file server or hybrid NAS/block level system might 
be ok..) as long as IT boots off it's own system (preferably SDD, flash, live 
CD, etc).  After all.. even hardware RAID is "software" at some level. :) 
(same argument can be made for hardware firewalls vs software firewalls to 
some degree).   And most of today's home NAS systems are just boxes running 
embedded Linux+LVM+SW-RAID anyway. But I digress... 

But running SW-RAID on the same system that's running your OS on?.. meh.. 
RAID-1 as most.. but I really wouldn't do much else.

One thing that I always recommend against is the cheap consumer 
motherboard/BIOS level and "thin" (proc/CPU-less) "hardware RAID".  Worst 
crap I've ever seen.. The BIOS/mobo variety is usually not supported well (or 
at all) by Linux/UN*X unless it's an embedded higher end server grade card or 
something (e.g. LSI, Adaptec, etc) with dedicated proc, battery backed RAM 
and write back cache.  Usually buggy.. Rarely upgraded at the BIOS flash or 
OS driver levels.  It's just a sales/marketing gimmick usually.  I played 
with cheap mobo and "thin HW-RAID" cards in the 90's and have seen people 
lose data too many times with low end promise cards ,etc.  Now I would only 
use the previously mentioned LSI, Adaptec, 3ware, etc. You get what you pay 
for.



> If it's the OS, my ultimate goal is a SW RAID1 of CF cards :)

Not a bad idea if this is the OS that's only running the OS that is in turn 
offering the HW-RAID NAS resources out to the network.  If that's what you 
were talking about doing.. yeah. that sounds cool to me.. :)

A somewhat "nicer" config might be to actually to run a Live-CD based NAS 
distro with config stored on CF or thumb drive.  Rock solid setup.  This is 
how I do my network firewall.  Combine that setup with an underclocked CPU 
with no fan and you've got an almost no-moving part system that's thermally 
rock solid too (almost like an expensive embedded system).


> That said, I could just backup to the Jungle :)

Yeah.. one of us should do an XCSSA presentation on just this subject! :)


> Anyways I went off on a tangent so I'll just stop here :)

Don't we all? :)


Sounds like one of us needs to do a home-brew NAS presentation.. tag team 
maybe Tim? How about you Firestorm(Matt)?  Sounds like we have varied 
perspectives.  Might be cool. :)

Tweeks