We've tested to run a virtual server(kvm) with a san disk atached. All seems ok, but if we do some heavy writes(dd if=/dev/null of=<file on san>) to the disk inside the vm, the filesystem goes to pieces. Our setup is like this:
On the host:
san -> fc -> multipath -> lvm
3par -> /dev/sdX -> /dev/mapper/Disk1 -> /dev/vg3
On the guest(stock debian lenny):
virtio -> lvm -> ext3
/dev/vdb -> /dev/vg1/vol1 -> /mnt
I've done a similar configuration with local disk, and that worked ok, but this seems to fail miserably. Does anyone have any advice on where to start? Can it be some bairrier problem?
One other question, would the performance be better if I "export" the fc card directly to the guest using iommu, and would that be a safe thing to do?
On the host:
san -> fc -> multipath -> lvm
3par -> /dev/sdX -> /dev/mapper/Disk1 -> /dev/vg3
On the guest(stock debian lenny):
virtio -> lvm -> ext3
/dev/vdb -> /dev/vg1/vol1 -> /mnt
I've done a similar configuration with local disk, and that worked ok, but this seems to fail miserably. Does anyone have any advice on where to start? Can it be some bairrier problem?
One other question, would the performance be better if I "export" the fc card directly to the guest using iommu, and would that be a safe thing to do?
