[one-users] Which is the best storage for One/KVM?

[Alberto Zuin - Liste]

Hello all,
in past for a customer I made a cloud with OpenNebula, XEN and a MooseFS 
storage: with a lot of chunk servers, the I/O latency of VM is acceptable.
Recently I made a little cloud for my personal purposes and also I made 
it with OpenNebula and MooseFS, but with KVM instead of XEN.
Sometimes, the I/O is very slow and the Kernel VM remounts the disk in 
read-only due to a timeout of 900 seconds (!!! I modified this setting 
in sysctl.conf).
In all 2 systems the images are always in raw format (I don't use qow), 
then I don't known if the difference is caused by KVM/XEN or by MooseFS 
chunckservers hardware (2 server with a replica of 2, instead of 5 
server with a relica of 3).
Now, I don't have enough time to make some tests: simply my setup is 
wrong and I have to make another one which works.
The question is: if you have to make a little cloud like mine, with 
OpenNebula, 2 KVM host and 2 servers for storage (each with 2 SATA disk 
that I want to substitute with WD Velociraptor 1 TB to be secure), what 
kind of storage technology you'll choose? The size is not a problem (now 
I use only 1 TB, then a total of 2 TB is OK), but the speed is important 
because mail and sql wants a solid I/O and obviously rock solid in case 
of failure.
MooseFS with better or more hardware? Another Cluster filesystem like 
Gluster o Chepth? A simple active/active DRBD?
Thanks,
Alberto

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