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From: "Richard W.M. Jones" <rjones@redhat.com>
To: Mike Snitzer <snitzer@redhat.com>
Cc: Heinz Mauelshagen <heinzm@redhat.com>,
	Zdenek Kabelac <zkabelac@redhat.com>,
	thornber@redhat.com,
	LVM general discussion and development <linux-lvm@redhat.com>
Subject: Re: [linux-lvm] Testing the new LVM cache feature
Date: Fri, 30 May 2014 15:29:48 +0100	[thread overview]
Message-ID: <20140530142948.GO1302@redhat.com> (raw)
In-Reply-To: <20140530135529.GC8830@redhat.com>

On Fri, May 30, 2014 at 09:55:29AM -0400, Mike Snitzer wrote:
> So unless you have misaligned IO you _should_ be able to avoid reading
> from the origin.  But XFS is in play here.. I'm wondering if it is

The filesystem is ext4.

> If you set read_promote_adjustment to 0 it should pull the associated
> blocks into the cache.  What makes you think it isn't?

The fio test is about twice as fast as when I ran the fio test
directly on the hard disk array.  This test runs about 5 times slower
than when I ran it directly on the SSD.

I'm not measuring the speed of the md5sum operation.

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
Read my programming and virtualization blog: http://rwmj.wordpress.com
virt-top is 'top' for virtual machines.  Tiny program with many
powerful monitoring features, net stats, disk stats, logging, etc.
http://people.redhat.com/~rjones/virt-top

  reply	other threads:[~2014-05-30 14:29 UTC|newest]

Thread overview: 37+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-05-22 10:18 [linux-lvm] Testing the new LVM cache feature Richard W.M. Jones
2014-05-22 14:43 ` Zdenek Kabelac
2014-05-22 15:22   ` Richard W.M. Jones
2014-05-22 15:49     ` Richard W.M. Jones
2014-05-22 18:04       ` Mike Snitzer
2014-05-22 18:13         ` Richard W.M. Jones
2014-05-29 13:52           ` Richard W.M. Jones
2014-05-29 20:34             ` Mike Snitzer
2014-05-29 20:47               ` Richard W.M. Jones
2014-05-29 21:06                 ` Mike Snitzer
2014-05-29 21:19                   ` Richard W.M. Jones
2014-05-29 21:58                     ` Mike Snitzer
2014-05-30  9:04                       ` Richard W.M. Jones
2014-05-30 10:30                         ` Richard W.M. Jones
2014-05-30 13:38                         ` Mike Snitzer
2014-05-30 13:40                           ` Richard W.M. Jones
2014-05-30 13:42                           ` Heinz Mauelshagen
2014-05-30 13:54                             ` Richard W.M. Jones
2014-05-30 13:58                               ` Zdenek Kabelac
2014-05-30 13:46                           ` Richard W.M. Jones
2014-05-30 13:54                             ` Heinz Mauelshagen
2014-05-30 14:26                               ` Richard W.M. Jones
2014-05-30 14:29                                 ` Mike Snitzer
2014-05-30 14:36                                   ` Richard W.M. Jones
2014-05-30 14:44                                     ` Mike Snitzer
2014-05-30 14:51                                       ` Richard W.M. Jones
2014-05-30 14:58                                         ` Mike Snitzer
2014-05-30 15:28                                           ` Richard W.M. Jones
2014-05-30 18:16                                             ` Mike Snitzer
2014-05-30 20:53                                               ` Mike Snitzer
2014-05-30 13:55                             ` Mike Snitzer
2014-05-30 14:29                               ` Richard W.M. Jones [this message]
2014-05-30 14:36                                 ` Mike Snitzer
2014-05-30 11:53                       ` Mike Snitzer
2014-05-30 11:38                 ` Alasdair G Kergon
2014-05-30 11:45                   ` Alasdair G Kergon
2014-05-30 12:45                     ` Werner Gold

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