Comments inline. On 05-Mar-2014, at 10:01 am, Nishan Sanjeewa Gunasekara <nishan.sanje...@gmail.com> wrote:
> Hi, > > I'm running CS 4.2.1 on XenServer 6.2 hosts. > > My primary storage is a ZFS file system provided via NFS. > > When I do a dd test directly from one of the hosts on the NFS mount I get a > write speed of about 150MBps > > dd if=/dev/zero of=test.dmp bs=1M conv=fdatasync count=1000 > 1000+0 records in > 1000+0 records out > 1048576000 bytes (1.0 GB) copied, 6.99829 seconds, 150 MB/s > > But when I do the same test on a Cloudstack VM running on the same host > (root disk on the same nfs mount ofcourse) I get a very low write speed. > 20MBps. > > dd if=/dev/zero of=test.dmp bs=1M conv=fdatasync count=1000 > 1000+0 records in > 1000+0 records out > 1048576000 bytes (1.0 GB) copied, 44.6171 s, 23.5 MB/s > > Any ideas how I can improve this ? Is this a PV VM? I just did a unscientific test in my lab on a PV VM. Results below: On the XenServer: [root@vxen1-1 ebb66062-d46f-7b3a-07be-b9ec583ec1a9]# dd if=/dev/zero of=test.dmp bs=1M conv=fdatasync count=1000 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 26.1396 seconds, 40.1 MB/s On a VM: [root@scan1 ~]# dd if=/dev/zero of=test.dmp bs=1M conv=fdatasync count=1000 1000+0 records in 1000+0 records out 1048576000 bytes (1.0 GB) copied, 29.4688 s, 35.6 MB/s I guess 10% is the virtual disk overhead. -- @shankerbalan M: +91 98860 60539 | O: +91 (80) 67935867 shanker.ba...@shapeblue.com | www.shapeblue.com | Twitter:@shapeblue ShapeBlue Services India LLP, 22nd floor, Unit 2201A, World Trade Centre, Bangalore - 560 055 Need Enterprise Grade Support for Apache CloudStack? Our CloudStack Infrastructure Support<http://shapeblue.com/cloudstack-infrastructure-support/> offers the best 24/7 SLA for CloudStack Environments. Apache CloudStack Bootcamp training courses **NEW!** CloudStack 4.2.1 training<http://shapeblue.com/cloudstack-training/> 18th-19th February 2014, Brazil. Classroom<http://shapeblue.com/cloudstack-training/> 17th-23rd March 2014, Region A. Instructor led, On-line<http://shapeblue.com/cloudstack-training/> 24th-28th March 2014, Region B. Instructor led, On-line<http://shapeblue.com/cloudstack-training/> 16th-20th June 2014, Region A. Instructor led, On-line<http://shapeblue.com/cloudstack-training/> 23rd-27th June 2014, Region B. Instructor led, On-line<http://shapeblue.com/cloudstack-training/> This email and any attachments to it may be confidential and are intended solely for the use of the individual to whom it is addressed. Any views or opinions expressed are solely those of the author and do not necessarily represent those of Shape Blue Ltd or related companies. If you are not the intended recipient of this email, you must neither take any action based upon its contents, nor copy or show it to anyone. Please contact the sender if you believe you have received this email in error. Shape Blue Ltd is a company incorporated in England & Wales. ShapeBlue Services India LLP is a company incorporated in India and is operated under license from Shape Blue Ltd. Shape Blue Brasil Consultoria Ltda is a company incorporated in Brasil and is operated under license from Shape Blue Ltd. ShapeBlue is a registered trademark.
