Megaraid with brakes on?

Peter Serwe peter at infostreet.com
Thu Jan 4 00:17:19 CST 2007


Martin Sarsale wrote:
>
> We're changing servers (not related to this issue) and we'll build a
> RAID10 in the new ones. What do you think it's better, assuming we
> want to have all the disks in a RAID?
> Hardware RAID0 and Software RAID1
> Software RAID0 and Hardware RAID1
> or Hardware RAID10 ?
>
> thanks a lot!
>   

Correct me if I'm wrong on this, but essentially, what was originally 
suggested
was (in fact) hardware raid 1 and software concatenation, which wouldn't 
really
be a combination of anything including raid 0, including raid 10, which 
would be
striping data across multiple drives, and probably wouldn't gain you any 
performance.

The simplest solution would probably be something like using raid 1 on 
several pairs,
and just mounting actual separate filesystems kind of like

/raiddisks/fs1
/raiddisks/fs2
/raiddisks/fs3

But that would require your application being aware of multiple 
filesystems to find this
data on, which may introduce a lot of extra complexity you don't need, 
which is where
the whole raid one and concatenate (don't stripe) the raid 1 pairs comes 
into play.

Come to think of it, this kind of sounds like what I should be doing for 
my 1.1TB
/Maildir/ as well, which makes a lot more sense than the raid 10 it's 
currently
configured as.  Splitting tiny file writes across a lot more spindles 
isn't going to
help either of us.

The next best alternative to running that, would probably be raid 10, I 
guess, but
I don't see the benefit for tons of tiny files, as previously pointed out.

Oh yeah, if anyone has any great ideas on my /Maildir/ filesystem, do 
tell.  I'm tempted
to run Reiser, but kind of scared of it's functionality, or longevity.

Peter

-- 
Peter Serwe <peter at infostreet dot com>
http://www.infostreet.com

"The only true sports are bullfighting, mountain climbing and auto racing." -Earnest Hemingway

"Because everything else requires only one ball." -Unknown



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