From: David Brown <david@westcontrol.com>
To: linux-raid@vger.kernel.org
Subject: Re: Resync intermittently writes to spare drives, waking them up
Date: Thu, 14 Apr 2011 10:32:53 +0200 [thread overview]
Message-ID: <io6bc0$6ol$1@dough.gmane.org> (raw)
In-Reply-To: <BANLkTikqAaS91n06Xw7SwWcMKik_8E0iHA@mail.gmail.com>
On 13/04/2011 23:10, Rory Jaffe wrote:
> I have a RAID5 array with 4 active devices and two spares. The spares
> are normally in sleep mode. I ran a resync with:
>
> echo repair> /sys/devices/virtual/block/md0/md/sync_action
>
> About 20 times (evenly spaced apart) during the resync, the spares
> were written to, waking them up. Is that behavior desired? It seems to
> me that it's a waste--I don't know why the resync would bother with
> the spares.
>
This isn't an answer to your question, but I would recommend changing to
a raid 6 with 5 devices and one spare. Raid 6 gives you /much/ better
reliability - you can thing of it as Raid 5 + hot spare with the hot
spare already synchronised.
next prev parent reply other threads:[~2011-04-14 8:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-04-13 21:10 Resync intermittently writes to spare drives, waking them up Rory Jaffe
2011-04-14 8:32 ` David Brown [this message]
2011-04-18 0:55 ` NeilBrown
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