Re: [libvirt-users] Behavior of disk caching with qcow2 disks

2014-08-14 Thread Andrew Martin
- Original Message - > From: "Kashyap Chamarthy" > > Looking at `qemu-img` source[1], 'cache=writeback' seems to be the > default. That's also corroborated by this[2] (Rich's blog, and > libguestfs/virt-tools lead developer). > > > [1] > > http://git.qemu.org/?p=qemu.git;a=blob;f=q

Re: [libvirt-users] Behavior of disk caching with qcow2 disks

2014-08-12 Thread Kashyap Chamarthy
On Mon, Aug 11, 2014 at 02:06:54PM -0500, Andrew Martin wrote: > Hello, > > I am running several virtualization servers with QEMU 1.4.x and > libvirt 1.0.2 on Ubuntu 12.04 and am working on optimizing the cache= > and aio= options for the virtual machines. These VM images are mostly > qcow2, and a

[libvirt-users] Behavior of disk caching with qcow2 disks

2014-08-11 Thread Andrew Martin
Hello, I am running several virtualization servers with QEMU 1.4.x and libvirt 1.0.2 on Ubuntu 12.04 and am working on optimizing the cache= and aio= options for the virtual machines. These VM images are mostly qcow2, and are served both from a local ext4 filesystem (with data=ordered,barrier) and