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From: maarten van den Berg <maarten@vbvb.nl>
To: Mario Giammarco <mgiammarco@virgilio.it>, linux-raid@vger.kernel.org
Subject: Re: RAID1 VS RAID5
Date: Sun, 26 Oct 2003 17:16:16 +0100	[thread overview]
Message-ID: <200310261716.17030.maarten@vbvb.nl> (raw)
In-Reply-To: <1067179519.1222.107.camel@cala>

On Sunday 26 October 2003 15:45, Mario Giammarco wrote:
> Hello,


> My problem is: I have seen that RAID1 code does not interleave reads so
> it does not improve performance very much putting two hard disks.

After thinking about your question for a minute, I think I found the obvious 
reason for that.  Raid1 being a mirror set it does not make sense to 
interleave anything. Either disk1 reads it first or disk2 reads it first. 
Once you get the data from either disk, then you're done; no need to wait for 
the second disk (giving you the identical datablock).  
Interleaving only makes sense with other raid levels, but not with level 1.

Maarten

-- 
Yes of course I'm sure it's the red cable. I guarante[^%!/+)F#0c|'NO CARRIER

  reply	other threads:[~2003-10-26 16:16 UTC|newest]

Thread overview: 20+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-10-26 14:45 RAID1 VS RAID5 Mario Giammarco
2003-10-26 16:16 ` maarten van den Berg [this message]
2003-10-26 18:22   ` Mario Giammarco
2003-10-27  8:27   ` Hermann Himmelbauer
2003-10-27  9:54     ` Lars Marowsky-Bree
2003-10-27 10:16     ` Jeff Woods
2003-10-28 10:45       ` Mario Giammarco
2003-10-27 11:08     ` maarten van den Berg
2003-10-27 12:03       ` Jeff Woods
2003-10-26 16:55 ` Matti Aarnio
2003-10-28 10:46   ` Mario Giammarco
2003-10-27  8:33 ` Hermann Himmelbauer
2003-10-27  9:19   ` Gordon Henderson
2003-10-27 11:01     ` Hermann Himmelbauer
2003-10-27 13:40       ` Gordon Henderson
2003-10-27 15:34         ` Hermann Himmelbauer
2003-10-27 14:17       ` Lars Marowsky-Bree
2003-10-27 15:52       ` Andrew Herdman
2003-10-28 10:40   ` Mario Giammarco
  -- strict thread matches above, loose matches on Subject: below --
2003-10-26 11:24 Mario Giammarco

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