Re: NetBSD RAID5 options (PCI-e controller?)

[buhrow%lothlorien.nfbcal.org@localhost (Brian Buhrow)]

        Hello.  I really like raid5 under raidframe.  I've been using it for
almost 10 years.  The parity calculation times are a problem, but on stable
systems, you rarely have to pay that penalty, and I like the ability to
manage the raid sets, i.e. do disk repairs and things on-line, without
having to bring the system down.  In my experience, and things may have
changed since I really looked at the issue, the management tools for
hardware raid cards always required you boot into a special bios, run
Windows, or otherwise get out of NetBSD to get actual management work done.
That, in my view, reduces their advantage, since one of the major selling
points of a raid set is that you can continue running uninterrupted during
disk failures.
The gsoc code looks intreaguing, and I'll be glad to see it pulled into the
project when it's ready.  That will make a great subsystem even better.
-Brian
On Jul 14,  5:25pm, Matthias Scheler wrote:
} Subject: Re: NetBSD RAID5 options (PCI-e controller?)
} On Tue, Jul 14, 2009 at 04:50:52PM +0100, David Brownlee wrote:
} >     I'd like to move to 2*1TB RAID1 for boot, OS, build etc and
} >     3*1.5TB raid5 for data files. Would people recommend raidframe
} >     raid5 or a dedicated raid controller?
} 
} A friend of mine has a massive RAID 5 using RAIDframe, something like
} 3x1TB and 3x1.5TB. It works fine but it needs a very long time to
} re-build the parity after an ungraceful shutdown. IIRC it takes over
} 24 hours.
} 
} If long re-builds are a problem in your case you probably want a
} hardware RAID controller. Alternatively you could wait for the
} result of RAIDframe GSoC project(*).
} 
}       Kind regards
} 
} (*) http://blog.netbsd.org/tnf/entry/google_summer_of_code_improving
} 
} -- 
} Matthias Scheler                                  http://zhadum.org.uk/
>-- End of excerpt from Matthias Scheler