LVM Configuration the Easy Way

Now oVirt features a simple way to prevent a host from scanning and then activating logical volumes that are not required directly by the host. In particular, the solution addresses logical volumes on shared storage managed by oVirt, and logical volumes created by a guest in oVirt raw volumes. Why is a solution required? Because scanning and activating other logical volumes may cause data corruption, slow boot, and other issues.

The solution is configuring an LVM filter on each host, which allows LVM on a host to scan only the logical volumes required directly by the host. To achieve this, we have introduced a vdsm-tool command, config-lvm-filter, that will configure the host for you.

The new command, vdsm-tool config-lvm-filter analyzes the current LVM configuration to decide whether a filter should be configured. Then, if the LVM filter has yet to be configured, the command generates an LVM filter option for this host, and adds the option to the LVM configuration.

Scenario 1: An Unconfigured Host

On a host yet to be configured, the command automatically configures the LVM once the user confirms the operation:

# vdsm-tool config-lvm-filter
Analyzing host...
Found these mounted logical volumes on this host:

  logical volume:  /dev/mapper/vg0-lv_home
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