Re: [CentOS] kvm cluster w/ c6

2013-10-21 Thread Andrew Holway
whats the best storage setup for KVM when using direct attached raid? surely using disk image files on a parent ext4/xfs file system isn't the best performance?Should I use host lvm logical volumes as guest vdisks? we're going to be running various database servers in dev/test and

Re: [CentOS] kvm cluster w/ c6

2013-10-21 Thread John R Pierce
On 10/21/2013 2:21 AM, Andrew Holway wrote: Remember that a single SATA harddrive has an approximate equivalent performance of 1G ethernet. 100MB/s or so. A) I have a SATA3 3TB disk on my windows PC that is twice that fast on sequential IO B) these new servers are SAS2 with 15k hybrid drives,

Re: [CentOS] kvm cluster w/ c6

2013-10-21 Thread Andrew Holway
On 21 October 2013 10:26, John R Pierce pie...@hogranch.com wrote: On 10/21/2013 2:21 AM, Andrew Holway wrote: Remember that a single SATA harddrive has an approximate equivalent performance of 1G ethernet. 100MB/s or so. A) I have a SATA3 3TB disk on my windows PC that is twice that fast on

Re: [CentOS] kvm cluster w/ c6

2013-10-21 Thread Alexander Dalloz
[ ... ] Remember that a single SATA harddrive has an approximate equivalent performance of 1G ethernet. 100MB/s or so. [... ] Andrew In the area of virtualization it is IOPS what counts, not sequential read/write. And in terms of IOPS SATA drives are the worst option as storage backend.

Re: [CentOS] kvm cluster w/ c6

2013-10-21 Thread Andrew Holway
On 21 October 2013 12:57, Alexander Dalloz ad+li...@uni-x.org wrote: [ ... ] Remember that a single SATA harddrive has an approximate equivalent performance of 1G ethernet. 100MB/s or so. [... ] Andrew In the area of virtualization it is IOPS what counts, not sequential read/write. And

Re: [CentOS] kvm cluster w/ c6

2013-10-21 Thread John R Pierce
On 10/21/2013 3:44 AM, Andrew Holway wrote: A) I have a SATA3 3TB disk on my windows PC that is twice that fast on sequential IO Really? what model? Seagate ST3000DM001 -- john r pierce 37N 122W somewhere on the middle of the left coast

[CentOS] kvm cluster w/ c6

2013-10-20 Thread John R Pierce
In our development lab, I am installing 4 new servers, that I want to use for hosting KVM. each server will have its own direct attached raid. I'd love to be able to 'pool' this storage, but over gigE, I probably shouldn't even try. most of the VM's will be running CentOS 5 and 6, some of

Re: [CentOS] kvm cluster w/ c6

2013-10-20 Thread Rainer Duffner
Am Sat, 19 Oct 2013 23:22:12 -0700 schrieb John R Pierce pie...@hogranch.com: In our development lab, I am installing 4 new servers, that I want to use for hosting KVM. each server will have its own direct attached raid. I'd love to be able to 'pool' this storage, but over gigE, I

Re: [CentOS] kvm cluster w/ c6

2013-10-20 Thread Digimer
On 20/10/13 02:22, John R Pierce wrote: In our development lab, I am installing 4 new servers, that I want to use for hosting KVM. each server will have its own direct attached raid. I'd love to be able to 'pool' this storage, but over gigE, I probably shouldn't even try. I've build

Re: [CentOS] kvm cluster w/ c6

2013-10-20 Thread John R Pierce
On 10/20/2013 8:55 AM, Rainer Duffner wrote: For your setup, I'd invest more in the hardware itself (redundant PSU, more redundancy in the disks, more powerful RAID-controller with battery-backed cache, the more hardware is hot-pluggable, the better etc..) got all that. dual PSUs which will