[CentOS] Re: raid5 crash

Bryan J. Smith b.j.smith at ieee.org
Sat Jul 9 22:50:33 UTC 2005


On Sat, 2005-07-09 at 23:40 +0200, Farkas Levente wrote:
> what happends if the 3ware card get wrong?
> do you always have a backup raid controller

The issue is no different than with tape cartridges.

Yes.  I _always_ deploy at least (2) 3Ware cards at any organization, so
there is a fall-back in the case of disaster.

> (with the same type)?

There is no such thing as "same type" with 3Ware.

As long as you put the volume in a device that is the same or newer
firmware, you're fine.

BTW, I have deployed over 50 (five-zero) 3Ware cards and have _never_
had a failure of a device yet.  Some are 4+ years old and still in use.

Plus I personally have an original 3Ware Escalade 7800 8-channel at home
I have upgraded from Red Hat Linux 6.1 to Fedora Core 3 -- *0* non-sense
with LVM/MD.

> with software raid you can plug it to any kind of controller
> and save your data!

That's what backup is for!  Geez.  ;->

And not always, if they disagree over low-level format.  I've had that
happen with different SCSI host adapters from different vendors on more
than one occasion (and even the same vendor -- OEM v. Retail Adaptec).

And when it comes to RAID-1, it's just a full disk mirror anyway.

> at the first place we start to use 3ware's raid5 when it's crashes at 
> the first week and we got a mail from 3ware that it's a known issue with 
> the current firmware. that was enough!

That was the 3Ware Escalade 6000 series.  3Ware added RAID-5 support
for the 6000 series when customers requested it.  3Ware regretted ever
doing such.

_Never_ seen an issue on the Escalade 7000+ series.

On the 6000 series, I always use just RAID-1 or RAID-10.  In many cases,
RAID-5 (regardless of implementation) is _not_ fast enough, so I use
RAID-10.

> how you can plug 1.5TB into machine? and the only good kernel support is 
> for 3ware (at least 2-3 years ago). that simple.

Hmmm, I thought RAIDCore's solution was integrated with LVM/MD?
And they _do_ have hot-plug last time I checked.

Just seems like a massive waste of the ASIC.

-- 
Bryan J. Smith                                     b.j.smith at ieee.org 
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