[Beowulf] Re: Large raid rebuild times

[Gerasimatos, Dimitrios V (343K)]

If rebuild times are a problem then I recommend you go with ZFS or a Netapp.
High-performance Netapp can be expensive. ZFS doesn't have to be. A fsck
of a large filesystem can easily take > 24 hours.


Dimitri


--
Dimitrios Gerasimatos                     dimitrios.gerasimatos at jpl.nasa.gov
Section 343                                        Jet Propulsion Laboratory
4800 Oak Grove Dr.           Mail Stop 264-820           Pasadena, CA  91109
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Subject: Beowulf Digest, Vol 69, Issue 22

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Today's Topics:

   1. Large raid rebuild times (james bardin)
   2. Re: Large raid rebuild times (Paul Van Allsburg)


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Message: 1
Date: Thu, 19 Nov 2009 13:18:41 -0500
From: james bardin <jbardin at bu.edu>
Subject: [Beowulf] Large raid rebuild times
To: beowulf at beowulf.org
Message-ID:
	<a3b675320911191018s43cba643p55d56c5df8b759ec at mail.gmail.com>
Content-Type: text/plain; charset=ISO-8859-1

Hello,

Has anyone here seen any numbers, or tested themselves, the rebuild
times for large raid arrays (raid 6 specifically)?
I can't seem to find anything concrete to go by, and I haven't had to
rebuild anything larger than a few TB. What happens when you loose a
2TB drive in a 20TB array for instance? Do any hardware raid solutions
help. I don't think ZFS is an option right now, so I'm looking at
Linux and/or hardware raid.


Thanks
-jim


------------------------------

Message: 2
Date: Thu, 19 Nov 2009 14:18:49 -0500
From: Paul Van Allsburg <vanallsburg at hope.edu>
Subject: Re: [Beowulf] Large raid rebuild times
To: james bardin <jbardin at bu.edu>
Cc: beowulf at beowulf.org
Message-ID: <4B059A19.909 at hope.edu>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed

james bardin wrote:
> Hello,
>
> Has anyone here seen any numbers, or tested themselves, the rebuild
> times for large raid arrays (raid 6 specifically)?
> I can't seem to find anything concrete to go by, and I haven't had to
> rebuild anything larger than a few TB. What happens when you loose a
> 2TB drive in a 20TB array for instance? Do any hardware raid solutions
> help. I don't think ZFS is an option right now, so I'm looking at
> Linux and/or hardware raid.
>
>
> Thanks
> -jim
> _______________________________________________
> Beowulf mailing list, Beowulf at beowulf.org sponsored by Penguin Computing
> To change your subscription (digest mode or unsubscribe) visit http://www.beowulf.org/mailman/listinfo/beowulf
>
>   
Jim,

I have a new Infortrend a24s-g2130 with 24 x 1T drives. I setup a raid6 
with 2 spares and during the raid initialization a drive failed. The 
raid6 initialization took 20 hours and the rebuild took 16 hours.  I've 
since changed the rebuild priority from normal to high but have not had 
any more drives fail.

Cheers,
Paul



http://www.infortrend.com/main/2_product/es_a24s-g2130.asp

-- 
Paul Van Allsburg       
Scientific Computing Specialist
Natural Sciences Division, Hope College
35 E. 12th St.  Holland, Michigan 49423
616-395-7292    vanallsburg at hope.edu
http://www.hope.edu/academic/csm/




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