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From: Heinz Mauelshagen <heinzm@redhat.com>
To: dm-devel@redhat.com
Subject: Re: raid1 round-robin scheduler
Date: Thu, 19 Feb 2015 16:02:20 +0100	[thread overview]
Message-ID: <54E5FAFC.3010800@redhat.com> (raw)
In-Reply-To: <54E58F6A.9040108@clodo.ru>



dm-mirror (i.e. "lvcreate --type mirror" or respective "dmsetup create 
--table ...",
which is not the recommended raid1 layout any more) provides read 
round-robin since long time.
You'd need an ancient kernel not to have it supported.

"raid1"/"raid10" (the recommended targets) , i.e. the md-raid based 
mappings accessible via the dm-raid target
do read optimizations as well. Use "lvcreate --type raid1/raid10 ..." or 
a respective dm table to set
those up. The former ("raid1") is the default in modern distributions 
and configurable via setting
'mirror_segtype_default = "raid1"' in /etc/lvm/lvm.conf.

Heinz




On 02/19/2015 08:23 AM, konstantin wrote:
> What version of the kernel should I use to get a round-robin read 
> implementation on LV raid1?
>

  reply	other threads:[~2015-02-19 15:02 UTC|newest]

Thread overview: 16+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-02-19  7:23 raid1 round-robin scheduler konstantin
2015-02-19 15:02 ` Heinz Mauelshagen [this message]
2015-03-10 11:55   ` konstantin
2015-03-10 14:22     ` Heinz Mauelshagen
2015-03-11  7:22       ` konstantin
2015-03-11 10:55         ` Heinz Mauelshagen
2015-03-11 12:44           ` konstantin
  -- strict thread matches above, loose matches on Subject: below --
2014-12-05 12:25 Vasiliy Tolstov
2014-12-05 12:38 ` Vasiliy Tolstov
2014-12-05 13:02   ` Bryn M. Reeves
2014-12-05 13:06     ` Zdenek Kabelac
2014-12-05 13:10       ` Vasiliy Tolstov
2014-12-05 13:08     ` Vasiliy Tolstov
2014-12-05 14:34       ` Bryn M. Reeves
2014-12-05 22:10         ` Vasiliy Tolstov
2014-12-08 12:23           ` Bryn M. Reeves

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