From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 30 May 2014 15:29:48 +0100 From: "Richard W.M. Jones" Message-ID: <20140530142948.GO1302@redhat.com> References: <20140529135246.GA31293@redhat.com> <20140529203410.GG1954@redhat.com> <20140529204719.GD1302@redhat.com> <20140529210648.GA3955@redhat.com> <20140529211955.GE1302@redhat.com> <20140529215815.GA4183@redhat.com> <20140530090422.GB31293@redhat.com> <20140530133814.GB8830@redhat.com> <20140530134642.GL1302@redhat.com> <20140530135529.GC8830@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20140530135529.GC8830@redhat.com> Subject: Re: [linux-lvm] Testing the new LVM cache feature Reply-To: LVM general discussion and development List-Id: LVM general discussion and development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , List-Id: Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Mike Snitzer Cc: Heinz Mauelshagen , Zdenek Kabelac , thornber@redhat.com, LVM general discussion and development 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