<div dir="ltr">qcow3 is supposed to address the qcow vs raw performance. The thing is qcow2 is so powerful as an image format it hardly makes sense to use anything else for os drives, at least in my opinion. If you need good performance, use a combination of qcow2 for transient storage and raw+lvm for persistent storage. </div>
<div class="gmail_extra"><br><br><div class="gmail_quote">On Fri, Jun 21, 2013 at 6:26 PM, Ruben S. Montero <span dir="ltr"><<a href="mailto:rsmontero@opennebula.org" target="_blank">rsmontero@opennebula.org</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">Hi<div><br></div><div>Try adding CACHE='none' in each DISK in the **VM template** to increase the performance. Usually qcow2 perform worse than raw format, because of the additional formatting needed. </div>
<div><br></div><div>If you want to test qcow2 you need to set DRIVER="qcow2" to the DISK attribute or image template. Additionally if the TM_MAD attribute of the datastore is set to qcow2 (e.g. onedatastore update), some operations take advantage of the qcow format, mainly snapshot to clone a disk.</div>
<div><br></div><div>Cheers</div><div><br></div><div>Ruben</div><div><br></div><div class="gmail_extra"><br><br><div class="gmail_quote"><div><div class="h5">On Fri, Jun 21, 2013 at 11:41 PM, Andrei Vakhnin <span dir="ltr"><<a href="mailto:andrey.a.vakhnin@nasa.gov" target="_blank">andrey.a.vakhnin@nasa.gov</a>></span> wrote:<br>
</div></div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><div><div class="h5">Hello,<br>
<br>
I am wondering if qcow2 datablock gives a better performance over raw format. Do I have to use separate datastore to be able to use qcow2 images? I am getting performance hit (only 12MB/s) when using 50GB non-persistent raw datablock formatted as ext3. Thanks<br>
<br>
200000+0 records in<br>
200000+0 records out<br>
1638400000 bytes (1.6 GB) copied, 157.853 s, 10.4 MB/s<br>
<br>
real 2m40.021s<br>
user 0m0.042s<br>
sys 0m3.839s<br>
<br>
oneadmin@xxx:~> oneimage show 38<br>
IMAGE 38 INFORMATION<br>
ID : 38<br>
NAME : data_loc<br>
USER : oneadmin<br>
GROUP : oneadmin<br>
DATASTORE : default<br>
TYPE : DATABLOCK<br>
REGISTER TIME : 12/05 15:34:46<br>
PERSISTENT : No<br>
SOURCE : /var/lib/one/datastores/1/bee8c51f03a40657a114ee3cf505d2a1<br>
FSTYPE : ext3<br>
SIZE : 48.8G<br>
STATE : used<br>
RUNNING_VMS : 2<br>
<br>
PERMISSIONS<br>
OWNER : um-<br>
GROUP : ---<br>
OTHER : ---<br>
<br>
IMAGE TEMPLATE<br>
DESCRIPTION="/data_loc"<br>
DEV_PREFIX="sd"<br>
DRIVER="raw"<br>
TARGET="sdc"<br>
<br>
Here is a template:<br>
<br>
DISK=[<br>
BUS="virtio",<br>
DRIVER="raw",<br>
IMAGE_ID="52",<br>
READONLY="no",<br>
TARGET="sdb" ]yes<br>
<br>
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<br></blockquote></div><br><br clear="all"><div><br></div>-- <br><span class="HOEnZb"><font color="#888888"><div dir="ltr"><div><div><div>-- </div><div>Join us at OpenNebulaConf2013 in Berlin, 24-26 September, 2013</div>
</div><div>-- </div></div>Ruben S. Montero, PhD<br>
Project co-Lead and Chief Architect<br>OpenNebula - The Open Source Solution for Data Center Virtualization<br><a href="http://www.OpenNebula.org" target="_blank">www.OpenNebula.org</a> | <a href="mailto:rsmontero@opennebula.org" target="_blank">rsmontero@opennebula.org</a> | @OpenNebula</div>
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