From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 22 May 2014 19:13:34 +0100 From: "Richard W.M. Jones" Message-ID: <20140522181334.GE1302@redhat.com> References: <20140522101837.GB14236@redhat.com> <537E0D25.7010108@redhat.com> <20140522152232.GC14236@redhat.com> <20140522154946.GD14236@redhat.com> <20140522180405.GA6361@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20140522180405.GA6361@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: Zdenek Kabelac , thornber@redhat.com, LVM general discussion and development On Thu, May 22, 2014 at 02:04:05PM -0400, Mike Snitzer wrote: > By default dm-cache (as is currently upstream) is _not_ going to cache > sequential IO, and it also isn't going to cache IO that is first > written. It waits for hit counts to elevate to the promote threshold. > So dm-cache effectively acts as a hot-spot cache by default. OK, that makes sense, thanks. I wrote about using the LVM cache feature here: https://rwmj.wordpress.com/2014/05/22/using-lvms-new-cache-feature/#content Rich. -- Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones Read my programming and virtualization blog: http://rwmj.wordpress.com virt-p2v converts physical machines to virtual machines. Boot with a live CD or over the network (PXE) and turn machines into KVM guests. http://libguestfs.org/virt-v2v