VVR supports replication of VxVM volumes and VxVM supports VxFS file systems.  VxVM has long supported encapsulation of native file systems for root / boot devices.  It is possible to run native file systems on VxVM volumes and replicate them using VVR.  This configuration has not been tested by Veritas beyond proof of concept testing for data migration use cases.

Replicating a native file system on a VxVM volume using VVR is logically equivalent to SAN based hardware replication, and the customer must understand the suitability / recoverability of replicating a native file system for their particular purpose.  Veritas would like to make the customer aware of a few scenarios when replicating using VVR:

1.       VVR only replicates data that has been flushed to VxVM.  File systems support buffered I/O, and any writes not flushed to VxVM will not be replicated.

2.       Native file system resize operations are not supported by the vxresize command.

3.       In-Band Control (IBC) messaging has been tested with VxFS and databases on raw volumes.  Native file system IBC messaging has not been tested.

4.       VxFS is a crash-consistent file system and can recover in the event of a crash.  Veritas makes no claims regarding the recoverability of native file systems in the event of a crash, and the ability of VVR to replicate native file systems is on an “as-is” basis.

5.       VVR does not support replication of encapsulated root volumes.

Veritas will provide VVR support of native file systems from the point that VxVM receives an incoming write until it is written on the secondary.  Veritas will not troubleshoot problems related to native file system source code.  For best performance, Veritas recommends running VxFS on VxVM volumes replicated using VVR.

Applies To

 VERITAS Volume Replicator 6.x onwards for all platforms.

Does VERITAS  Volume Replicator ( VVR) support replication of native file systems?