I'm trying to make 3-way replication (dual primary+secondary) with DRBD, whilst having both servers write to drbd (via LVM). I set this up and started VMs residing on LVM on upper-layer DRBD (of course different LVs, I don't start same VMs on different hosts) I got DRBD "Concurrent write detected!" and get frozen drbd and a big hang up of all VMs.
I guess this is because drbd doesn't like that it gets written to by LVM AND at the same moment, lower-level DRBD changes because of sync with another host. I have read that in order to do what I want to do I need to use OCFS2. BUT - how do I do LVM on top of cluster fs? Cluster FS would mean using files instead of LVM. Am i right?
My current setup is
HOST1: sda->sda1->drbd0(lower-layer, Primary, sync with HOST2)->drbd10(upper-layer, Primary, sync with 3rd node)->LVM
HOST2: sda->sda1->drbd0(lower-layer, Primary, sync with HOST1)->drbd10(StandAlone, Primary, so that only one host would sync with HOST3)->LVM
HOST3: sda->sda1->drbd10(Secondary, sync with HOST1)
Everything works fine until I start writing concurrently on both HOST1 and HOST2.
Is there something really wrong with my setup? Will this work with OCFS2 or I need to change my structure somehow?
I guess this is because drbd doesn't like that it gets written to by LVM AND at the same moment, lower-level DRBD changes because of sync with another host. I have read that in order to do what I want to do I need to use OCFS2. BUT - how do I do LVM on top of cluster fs? Cluster FS would mean using files instead of LVM. Am i right?
My current setup is
HOST1: sda->sda1->drbd0(lower-layer, Primary, sync with HOST2)->drbd10(upper-layer, Primary, sync with 3rd node)->LVM
HOST2: sda->sda1->drbd0(lower-layer, Primary, sync with HOST1)->drbd10(StandAlone, Primary, so that only one host would sync with HOST3)->LVM
HOST3: sda->sda1->drbd10(Secondary, sync with HOST1)
Everything works fine until I start writing concurrently on both HOST1 and HOST2.
Is there something really wrong with my setup? Will this work with OCFS2 or I need to change my structure somehow?