Gluster Volume Asynchronous Tasks Management enables users to re-balance volumes and remove bricks in Gluster operations and in Gluster volumes.

The "Multiple Storage Domains" feature enables a virtual machine to spread its disks across several storage domains within the same datacenter.

The "Read-Only Disk for Engine" feature gives the engine (Red Hat Enterprise Virtualization Manager) the read-only disk capability found in VDSM.

The "Single-disk Snapshot" feature enables the creation of a customized snapshot. This allows the user to select from which disks to take a snapshot.

After the manager is upgraded to 3.4.0, the ETL Service returns the following error:

You have upgraded your oVirt Engine and now require an upgrade of the ovirt-engine-dwh package.  Upgrade using yum and run ovirt-engine-dwh-setup. Service will now exit.

Due to upgrade flow changes in 3.4.0, the user must take one of the following steps:

After a LUN has been expanded from the storage side, pvresize is now run in order to retrieve the correct storage domain volume group size.

Previously, on block domains, when a thinly-provisioned disk neared its limit, the host running it requested that the SPM (Storage Pool Manager) extend the volume. This was done by writing a message to a pre-defined volume on the master storage domain called the mailbox. The SPM then monitored this mailbox, and handled the requests for extension.

RHEVM 3.4 introduced mixed storage domains, allowing master file domains to be in charge of block domains.

RHEVM 3.4 creates the mailbox on the master storage domain, regardless of its type.

Previously, RHEV allowed the configuration of only one path to the iSCSI target, using only one interface. This was a single point of failure. Using multiple paths allows automatic failover and provides better throughput.

Red Hat Enterprise Virtualization Manager introduced a new subtab called iSCSI Multipathing under the Data Center tab, which allowed creation and management of groups of logical networks and ISCSI storage connections for the purpose of configuring iSCSI multipathing. Such groups are known as "iSCSI Bond". When these bonded targets have been configured, the engine attempts to connect each host to each bonded target by means of each NIC and VLAN related to the logical networks of the same iSCSI Bond.