[ale] Build-yer-own NAS server

[Greg Freemyer]

On 6/6/06, J. D. <jdonline at gmail.com> wrote:
>
>
> > > Just the drives.  I've seen 300MB drives on special < $100, so the 1TB
> > > is withing reach.
>
>
> Ahh I see. That type of configuration (with three drives totalling 900GB) is
> a raid0. It can be kind of scary because it means if one drive fails, all
> the data is lost. The nerve-wracking thing it would be that hard drives are
> one of the two most likely to fail devices in a system because of their
> moving parts.
>
> > Looks like I need to read up on RAID.  Any suggestions for a good primer?
>
> http://www.linuxhomenetworking.com/linux-adv/raid.htm
>
> This article is an interesting read and covers a lot of key stuff like
> descriptinon of raid types, choosing the drives, and making it work in
> linux. My interpretation of the article is to steer clear of IDE for raid
> because two drives on the same cable limit redundancy. One drive can fail
> and cause the other not to function occassionally. But it may still be fine
> for a home setup.
>
> I personally use a two drive lvm span set of two 80gig drives for 150gig or
> so total storage. Ideally this should be a raid5 but the drive I was going
> to use failed... That data is rsync'd nightly to another machine through a
> little creative shell scripting. It isn't terribly elegant but it works well
> enough. ;)
>
> Best regards,
>
> J. D.

If you want to use IDE, then use a card like the 3ware controller that
only supports one IDE drive per cable.  (ie. Masters only, no slaves).
 I have not priced one in a few years, but they used to be about
$100/drive.  ie. ~$400 for a 4 drive controller.

Personally I would look at SATA drives.  They are normally one drive
per cable so you don't have the cable issue.  I priced a single 750 GB
SATA drive last week for under $500 (It was either Maxtor or Seagate).
 With 2 of those you could get 750 GB in Raid 0 for $1000.  Not too
far from the $1000/TB number.

FYI: The linux kernel sata subsystem is getting a huge re-write to its
error handler (EH).  IIRC, it is in the -mm kernel and is planned to
go into the 2.6.18 kernel expected in the August timeframe.

I have been avoiding SATA with Linux due to the poor EH capability.
WIth the new EH, I believe Linux/Sata will finally be ready for
production use.  OTOH, it may take a few more months to shake out the
new EH.  So I will wait to see how stable it appears to be once it
comes out.

Greg
-- 
Greg Freemyer
The Norcross Group
Forensics for the 21st Century