Veritas InfoScale™ 7.4 Release Notes - Linux

Front-End Log (FEL)-based write-back caching for applications running on VxFS file systems

InfoScale introduces Front-End Log (FEL)-based write-back caching for applications running on VxFS file systems, having Disk Layout Version (DLV) 14 and later.

InfoScale Storage and InfoScale Enterprise supports write-back caching on solid-state drives (SSDs) for applications running on Veritas File System (VxFS) file systems. In case of DLV 14 and later, application writes are cached in a Front-End Log (FEL)-based writeback device.

The FEL-based writeback caching mechanism is functionally similar to that of the SmartIO write-back cache. However, many aspects of the FEL-based design is expected to result in better performance than SmartIO write-back caching. Also, the FEL-based write-back caching removes the restriction of two node cluster, which was present in the SmartIO write-back cache. Since both the caching types are functionally similar, the FEL-based write-back caching is a replacement for the SmartIO write-back caching, on DLV 14 and later. FEL-based write-back caching continues to use many of the user management interfaces as the SmartIO write-back cache. For older disk layouts i.e. DLV 13 and prior, SmartIO write-back caching mechanism remains unchanged.

An FEL-based write-back cache is a volume that is separate from the primary volumes of a filesystem which is used as a persistent staging area, allowing synchronous writes to return quickly to the user, regardless of the complexity of the write itself.

For more details about creating an FEL-based cache area and other related details, see Veritas InfoScale™ 7.4 SmartIO for Solid-State Drives Solutions Guide - Linux.