[linux-lvm] new to cLVM - some principal questions

[Lentes, Bernd]

Hi,

i have a bit experience in LVM, but not in cLVM. So i have some principal questions:
My idea is to establish a HA-Cluster with two nodes. The ressources which are managed by the cluster are virtual machines (KVM).
I have a FC SAN, where the vm's will reside. I want to create vdisks in my SAN which are integrated as a PV in both hosts. On top of the PV's i will create a VG, and finally LV's. For each VM one LV.

How are things going with cLVM ? Do i have to create PV ==> VG ==> LV seperately ? Or does cLVM replicate the information from one host to the other ? So that i have to create PV, VG and LV only once on the first node and this configuration is replicated to the second host.

What is about e.g. resizing a LV ? Is this replicated, or do i have to resize twice, on each host ?

E.g. one host is running VM3 in the corresponding lv3 on the first host. Is the second host able to access lv3 simultaneously or is there a kind of locking ?

Is it possible to run some vm's on the first host and others on the second (as a kind of load-balancing) ?

Is it possible to perform a live-migration from one host to the other in this scenario ?

I will not install a filesystem in the lv's, because i got recommendations to run the vm's in bare partitions, this would be faster.


Thanks for any eye-opening answer.


Bernd

--
Bernd Lentes

Systemadministration
Institut für Entwicklungsgenetik
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