Veritas InfoScale Storage and Veritas InfoScale Enterprise provides SmartIO─ a data caching solution that helps in improving I/O performance of applications by providing a read-only/write-through I/O cache on locally attached Solid State drives (SSDs).
The locally attached SSDs serve to be a bottleneck for VMware vMotion. VMware vMotion fails if any disk is locally attached to a virtual machine.
To over come this limitation InfoScale provides a solution that replaces the SSDs with SmartDisks. SmartDisks are the disks that are assigned by Veritas Dynamic Multi-Pathing for VMware (VxDMP). These disks are provisioned from an aggregated pool of SSDs and a single SmartDisk is exposed to a virtual machine as a RAW LUN.
SmartIO behavior after vMotion
The first I/O to the cache area fails and the request is forwarded to the back-end storage (data disks). InfoScale Storage considers the I/O failure as a vMotion event and informs the VxDMP layer to allocate a SmartDisk of the required capacity. After the VxDMP layer allocates a SmartDisk, InfoScale Storage retrieves the cache area details from the registry and creates a similar cache area on the SmartDisk. This newly created cache area is assigned to the virtual machine after vMotion.
Note: If the cache area is offline during vMotion, InfoScale Storage does not recreate the cache area on the SmartDisk attached to the target host. Admin intervention is required to bring the cache area online. When a subsequent I/O fails after the cache is brought online, InfoScale Storage initiates the SmartDisk allocation process.
For more details about SmartIO, see: