[Users] iSCSI Storage mirror

[Jaco]

Hi guys,

Got my system (3.2 on CentOS 6.3 - PoC lab v.0.99999) working fairly OK, 
with a few issues that's of concern to me.

I've now started using iSCSI storage, but kept running into an issue 
where the VM's would go into a paused state.

A bit of digging in the logs show that it's because of a timeout issue 
talking to the iSCSI server/target, which for me raises the spectre of 
potential corruption, especially under load.
Couldn't understand how this was possible, as I went out & bought some 
dedicated hardware to set up a totally separate & isolated "storage" 
network, but ended up simply running a cross-over UTP between the 
machines (process-of-elimination & all that), but the issue persisted.
This morning I found that one of the mirrored drives started failing, so 
(until I've replaced the drive & discovered otherwise) I suspect that 
may be the possible cause of the issue.

What occurred to me last night, as this thing was keeping me awake, is 
that this might not be the *best* course of action, and started thinking 
that maybe another way of doing it, especially since oVirt does some 
fairly low-level LVM stuff, is to rather store the VM's on a local 
drive, get far better IOPS than I could hope for with iSCSI over GBE, 
and rather set up the iSCSI to mirror the local device.
That way the data is still available on the target in the event a 
fail-over/migration needs to take place, but that I'm reducing the risks 
a bit while improving overall performance.

Is there a way to do this via oVirt, or would I have to do it manually 
by setting up storage locally & set up the mirroring via iSCSI manually 
as an OS-level?
And if so, what would I be looking for & what sort of caveats would I 
have to keep in mind in order to make this setup suitable for use by 
multiple hosts in the event a (live-)migration needs to take place? (I'm 
pretty new at the iSCSI-thing & LVM knowledge is just passable)

I'd appreciate anyone's insights into this subject

Kind regards

- Jaco